Cylinder apparatus

A cylinder apparatus sealingly containing functional fluid having a fluid property changing according to an electric field, the cylinder apparatus including a rod inserted therein, the cylinder apparatus comprising:

• an inner cylinder electrode and an outer cylinder electrode provided outside this inner cylinder electrode, the inner cylinder electrode and the outer cylinder electrode serving as electrodes of potentials different from each other;
• and
• one or a plurality of flow passage formation unit(s) provided between the inner cylinder electrode and the outer cylinder electrode, the one or plurality of flow passage formation unit(s) forming a plurality of flow passages through which the functional fluid flows at least according to an extension-side movement of the rod from one end side toward an opposite end side in an axial direction,
• wherein the flow passages formed by the one or plurality of flow passage formation unit(s) are each a helical or serpentine flow passage having a circumferentially extending portion, and provided in such a manner that an effective cross-sectional area of the flow passage on at least one of an entrance and an exit is large compared to an effective cross-sectional area of an intermediate portion of this flow passage,
• wherein the flow passage formation unit(s) comprise(s) one or a plurality of seal unit(s) provided so as to be inclined at some inclination angle with respect to the axial direction, and
• wherein the inclination angle of each of the seal unit(s) is not constant, and a sharply inclined portion inclined at a large inclination angle is provided at least on an entrance of an extension-side flow passage.