  The magnetic dipole ($M$1) resonances of even-even $^{112-120, 124}$Sn
isotopes are investigated in the framework of the self-consistent Skyrme
Hartree-Fock (HF) + BCS and Quasiparticle Random Phase Approximation (QRPA).
The Skyrme energy density functionals SLy5 and T11 with and without tensor
terms are adopted in our calculations. The mixed type pairing interaction is
used to take care of the pairing effect for open-shell nuclei both in the
ground and excited states calculations. The calculated magnetic dipole
strengths are compared with available experimental data. The QRPA results
calculated by SLy5 and T11 with tensor force show a better agreement with the
experimental data than those without the tensor force. By analyzing the HF and
QRPA strength distributions of $^{112}$Sn and $^{124}$Sn, we discuss the effect
of tensor force on the $M$1 resonances in detail. It is found that the $M$1
resonance is sensitive to the tensor interaction, and favors especially a
negative triplet-odd tensor one. Depending on the nucleus, a quenching factor
of the $M$1 operator of about 0.71-0.95 is needed to reproduce the total
observed transition strength. In our calculations, we also find some low-lying,
pygmy-type magnetic dipole states distributed below 6.0 MeV, and they are
formed mainly from the neutron configuration
$\nu$2$d_{5/2}$$\rightarrow$$\nu$2$d_{3/2}$.
