The invention provides a fast-extending and slow-contracting
hydraulic cylinder. The
hydraulic cylinder mainly comprises a cylinder
barrel, a
piston rod, a
piston, a buffer sleeve, a
jet flow passage, an acceleration sleeve, a guide buffer sleeve, an end cover B and an end cover A. The fast-extending and slow-contracting
hydraulic cylinder is characterized in that the
piston rod can extend fast and contract slowly. According to the fast-extending and slow-contracting hydraulic cylinder, the buffer sleeve with one inwardly
concave side and an angular
jet flow passage are arranged, so that the slow contracting of the
piston rod is realized; the parabola-shaped acceleration sleeve is arranged, so that the fast extending of the
piston rod is realized; the parabola-shaped inwardly-concave guide buffer sleeve is arranged, and an annular
blind hole is formed in the guide buffer sleeve, so that buffer stop of the acceleration sleeve is realized, the extension length of the
piston rod is increased, and soft start contraction of the piston rod is realized; a
check valve is arranged on the cylinder
barrel, so that high-pressure air in the cylinder is discharged; elastic pads are arranged between the end cover B and the guide buffer sleeve, so that
impact on the guide buffer sleeve generated by fluid is absorbed; oil grooves and sealing rings are arranged on the outer side surface of the piston, so that oil leakage,
temporary storage of impurities in oil and sealing of the piston are realized.