  The dynamical effect of the cosmological constant $\Lambda$ on a single
spherical void evolving in a the universe is investigated within a non linear
perturbation of Newton-Friedmann models. The void expands with a huge initial
burst which freezes asymptotically with time up to matching Hubble flow. For
$\Omega_{\circ}\sim 0.3$, $\Lambda$-effect on the kinematics intervenes
significantly by amplifying the expansion rate at redshift $z\sim 1.7$. As a
result, the size increases with the background density and with $\Lambda$, what
interprets by the gravitational attraction of borders from outside regions and
the gravitational repulsion of borders. The velocity flow within the void
region depends solely on $\Lambda$, it reads $\vec{v}=\sqrt{\Lambda/3}\vec{r}$.
Hence, the empty regions are swept out for spatially closed Friedmann models
what provides us with a stability criterion.
