Un approccio Problem Solving alle tolleranze dimensionali e geometriche

In this paper we propose a problem solving approach to the dimensional and geometric tolerances. This approach starts from simple geometrical remarks concerning the functional/ assembly characteristics of a part. It assigns the geometric tolerances to the features by a method that connects the degrees of freedom to the measurements. For instance, the contact of a face on a plane, which cancels three degrees of freedom, allows the measurement of the forbidden translation (distance of a point, an axis, or a plane from the contact plane of the face) and the measurements of the forbidden rotations (angles between an axis or a plane and the contact plane of the face). Points, axes and planes are associated with features: a point to a spherical feature, an axis to a hole/shaft feature, a plane to a slot/tab feature or to a face. We have chosen the envelope mode to avoid the introduction of the spines related to the determination of central lines and median surfaces.