Direct current load breaking contact point constitution and switching mechanism therewith

摘要

The invention intends to provide a direct current load breaking contact point constitution that can make and break an electrical circuit under both direct current loads of direct current resistance load and direct current inductance load over a long period of time without causing problems such as {circle around (1 the conduction defect due to the consumption of the contact point, {circle around (2 the locking due to material transfer from one contact point to the other contact point, {circle around (3 the welding between the contact points, and {circle around (4 the abnormal arc continuation, and a direct current load breaking switching mechanism such as a relay, a switch and so on that has the contact point constitution. The direct current load breaking contact point constitution according to the invention comprises a movable contact point and a stationary contact point that face each other; wherein the movable contact point is made of AgSnO₂In₂O₃ alloy that contains at least Ag, 8 to 15% by weight in total of metal oxides including SnO₂ and In₂O₃, 6 to 10% by weight of SnO₂ and 1 to 5% by weight of In₂O₃; the stationary contact point is made of AgZnO alloy that contains at least Ag and 7 to 11% by weight of ZnO; and polarity of a movable side is (+) and that of a stationary side is (-).