Knee joint component, knee joint and artificial leg

A knee joint component to be mounted on a hydraulic cylinder including, a cylinder tube coupled to a socket to be mounted on a thigh part, an oil chamber formed in said cylinder tube, and an oil filled in said oil chamber,

• and a rod coupled to an artificial lower leg part, and a piston that divides said oil chamber into a first oil chamber and a second oil chamber and that moves with the movement of said rod,
• the knee joint component comprising;
• a first passage connecting said first oil chamber and said second oil chamber, and having a first passage characteristic as said oil passes through when said piston is moving from said first oil chamber toward said second oil chamber;
• a second passage arranged so as to be parallel to said first passage, and having a second passage characteristic in which a hydraulic resistance of said oil is higher than that of said first characteristic when said piston is moving from said first oil chamber toward said second oil chamber;
• a third oil passage connecting said first oil chamber and said second oil chamber, and is passed through said oil when said piston is moving from said second oil chamber toward said first oil chamber;
• a switching mechanism for switching whether said oil passes through either said first oil passage or said second oil passage;
• and
• said second oil passage has an inlet/outlet of said oil on the way;
• and said switching mechanism has a first rotating member that rotatably attaches around a first rotating shaft, and that rotates around said first rotating shaft when said artificial lower leg part is tilted, and has a second rotating member that rotatably attaches around a second rotating shaft of said first rotating member, and that rotates around said second rotating shaft when said artificial lower leg part is tilted, and that switches said oil through either said first oil passage or said second oil passage by opening or closing said inlet/outlet of said second oil passage.