An upper frame for construction equipment mounted to swing on a lower
driving structure is provided, in which fixing pins for supporting a boom
and a boom cylinder are coupled to left and right side plates that are
welded on a base plate to face each other, and a plate-shaped joint
connection plate is welded on the left and right side plates and the base
plate, so as to support the left and right side plates by exhibiting the
rigidity and flexibility against load being transferred to the fixing
pins through a working device during working. The upper frame includes a
base plate on which a driving means for swing the upper frame is mounted,
left and right side plates vertically welded on the base plate to face
each other and composed of inner and outer vertical plates to which a
boom and a boom cylinder are rotatably fixed by fixing pins,
respectively, and a joint connection plate having both sides welded on
inner sides of the inner vertical plates and a lower end part welded on
the base plate and supporting the left and right side plates by
exhibiting rigidity and flexibility when reaction load from the boom is
generated on the fixing pins due to load generated on the working device
during working.