Hydraulic jack

A hydraulic jack, comprising:

• a base as a carrier for mounting other components;
• an inner cylinder barrel (4) vertically fixed to the base, a sliding cavity being formed in the inner cylinder barrel (4);
• an outer cylinder barrel (2) vertically and slidably fitted outside the inner cylinder barrel (4);
• a valve plug assembly slidably fitted in the sliding cavity, the sliding direction of the valve plug assembly being parallel to the axis direction of the inner cylinder barrel (4), and the valve plug assembly being rigidly connected to the outer cylinder barrel (2) via a valve plug rod (5) and being able to slide synchronously with the outer cylinder barrel (2);
• a valve plug driving assembly mounted on the outer cylinder barrel (2) and used for driving the valve plug assembly to slide up and down;
• and
• a supporting component mounted on the side wall of the outer cylinder barrel (2) in an up-down adjustable mode and used for supporting a lifting object;
• wherein the valve plug assembly comprises a valve plug main body (3) slidably fitted in the sliding cavity, the valve plug main body (3) separates the sliding cavity into a lower cavity (40a) and an upper cavity (40b), a one-way valve assembly for one-way communication between the lower cavity (40a) and the upper cavity (40b) is formed in the valve plug main body (3), the top of the valve plug main body (3) is rigidly connected to the outer cylinder barrel (2) via a cylinder sleeve (5), a second sliding cavity is formed in the cylinder sleeve, the second sliding cavity is in communication with the one-way valve assembly, and a sliding plug (61) is slidably fitted in the second sliding cavity;
• a sliding plug rod (6) is disposed on the sliding plug, the sliding plug rod (6) extends upwards to the outside of the outer cylinder barrel (2) and is connected to a rocking handle (26) hinged to the outer cylinder barrel (2), and the sliding plug is driven to move up and down by swinging the rocking handle (26) back and forth, so that hydraulic oil in the upper cavity (40b) enters the lower cavity (40a) via the one-way valve assembly and the outer cylinder barrel (2) is jacked up.