Cylinder apparatus

A cylinder apparatus comprising:

• functional fluid sealingly contained in the cylinder apparatus, the functional fluid having a fluid property changing according to an electric field;
• an inner tube electrode;
• a rod inserted inside the inner tube electrode;
• and
• an outer tube electrode,
• wherein the inner tube electrode and the outer tube electrode are electrodes having different potentials from each other,
• wherein the outer tube electrode is provided outside the inner tube electrode,
• wherein the cylinder apparatus further includes a flow passage formed between the inner tube electrode and the outer tube electrode, the flow passage being configured in such a manner that the functional fluid flows from one axial end side toward the other axial end side due to at least an extension-side movement of the rod,
• wherein the flow passage defines a first end region, a second end region, and an intermediate region between the first and second end regions,
• wherein the flow passage includes a flow passage cross-sectional area change portion configured such that a cross-sectional area of the flow passage of the intermediate portion of the flow passage is larger than a cross-sectional area of the flow passage of the first end region of the flow passage,
• wherein a plurality of seal portions is provided in the flow passage,
• wherein the plurality of seal portions includes short partition walls provided in the first end region of the flow passage and a plurality of long partition walls,
• wherein the long partition walls are longer than the short partition walls and extend helically continuously from an end of the first end region of the flow passage through at least the intermediate region of the flow passage, and
• wherein the number of seal portions provided in the intermediate region of the flow passage is less than the number of seal portions provided in the first end region of the flow passage.