Within the framework of the $\cal CP$ conserving Two
Higgs Doublet Models (2HDM) type I and II we investigate
the di-Higgs production at future $e^+e^-$ colliders in order to
find effects coming from triple Higgs couplings.
We define and explore some benchmark planes
that show large values of these couplings, still in agreement
with all the relevant theoretical and experimental constraints.
Within those planes two production channels are considered:
$e^+e^-\to h_ih_jZ$ and $e^+e^-\to h_ih_j\nu\bar{\nu}$,
with $h_ih_j=hh,\ HH\ \mathrm{and}\ AA$.
We discuss on the sensitivity to $\kappa_\lambda:=\lambda_{hhh}/\lambda_{hhh}^\mathrm{SM}$ and $\lambda_{hhH}$ in the $hh\nu\bar{\nu}$ production and
to $\lambda_{hHH}$ ($\lambda_{hAA}$) in the $HH\nu\bar{\nu}$ ($AA\nu\bar{\nu}$) production at CLIC 3 TeV
via the cross section distribution on the invariant mass of the final-state Higgs-pair.