Electromagnetic contactor

1. An electromagnetic contactor, comprising:

a contact conductor portion including a fixed contact portion having a first contact portion and first contact end portions formed at lateral ends of the first contact portion, a fixed contact attachment portion spaced apart from the fixed contact portion to form a space therebetween, an intermediate portion integrally linking the fixed contact portion and the fixed contact attachment portion to form a C-shaped portion, and chamfered portions each being formed on each side of the fixed contact portion and extending to the fixed contact attachment portion through the intermediate portion along each inner corner portion of the C-shaped portion, wherein the first contact end portion is a part of the chamfered portion;

a movable contact portion disposed in the space between the fixed contact portion and the fixed contact attachment portion, and having a second contact portion and second contact end portions formed at lateral ends of the second contact portion, respectively facing the first contact portion and the first contact end portions, the second contact portion contacting to and separating from the first contact portion,

an insulating cover disposed between the fixed contact attachment portion and the movable contact portion, the insulating cover including an opposing surface portion facing a surface opposite to the second contact portion of the movable contact portion, and left and right upright portions formed on two sides of the opposing surface portion and extending in a direction away from the movable contact portion, and

an arc extinguishing receptacle forming an arc extinguishing chamber housing the fixed contact portion and movable contact portion,

wherein the first contact end portion is chamfered such that a distance between the first contact end portion of the fixed contact portion and the second contact end portion of the movable contact portion increases in a moving direction of an arc generated when separating the second contact portion from the first contact portion,

the intermediate portion extends in a direction intersecting the moving direction of the arc,

a width dimension of the opposing surface portion is smaller than that of the movable contact portion in a direction along the moving direction of the arc, and

the left and right upright portions have shapes corresponding to the chamfered portions of the fixed contact attachment portion to extend the arc upwardly in the arc extinguishing chamber.

2. The electromagnetic contactor according to claim 1 , wherein the movable contact portion further includes a chamfered portion formed on each second contact end portion such that a distance between the first contact end portion and the second contact end portion further increases toward each end of the second contact end portions positioned in the moving direction of the arc.

3. The electromagnetic contactor according to claim 1 , wherein the contact conductor portion further includes a small diameter portion having a diameter smaller than the width dimension of the opposing surface portion; and

the insulating cover further includes fitting portions inwardly projecting from ends of the left and right upright portions to fit into the small diameter portion of the contact conductor portion.