Liquid storage tank upper cover assembly of drawing or adding liquid machine and drawing or adding liquid machine

A drawing or adding liquid machine, wherein the drawing or adding liquid machine comprises a liquid storage tank upper cover assembly, the liquid storage tank upper cover assembly comprises an upper cover, a switching valve foundation disposed at an upper end of the upper cover and a valve cartridge cooperated with the switching valve foundation, the upper cover and the switching valve foundation are a one-piece molded part, the switching valve foundation has a sliding hole, a lower part of the upper cover has a first through-hole and a second through-hole, a the first through-hole and the second through-hole are spaced apart, the first through-hole and the second through-hole are both connected to the sliding hole, the switching valve foundation has a third through-hole connected with the sliding hole;

• the valve cartridge is glidingly provided in the sliding hole, the valve cartridge has a first working position and a second working position, when the valve cartridge is in the first working position, the first through-hole and the third through-hole are hermetically connected, the second through-hole is connected with an external air by the sliding hole, when the valve cartridge is in the second working position, the second through-hole and the third through-hole are hermetically connected, and the first through-hole is connected with the external air by the sliding hole;
• the drawing or adding liquid machine further comprises:
• a pump, an upper part of a side wall of the pump has a first air vent, a lower part of a side wall of the pump has a second air vent, the first air vent is connected with a lower end of the first through-hole through a first pipeline, the second air vent is connected with a lower end of the second through-hole through a second pipeline, the second pipeline has a one-way valve structure, and the one-way valve structure is used to prevent the air from flowing into the pump from the second pipeline;
• a piston assembly, is disposed at the pump movably up and down, the piston assembly is divides the pump into an upper space and a lower space, when the piston assembly moves downward, the upper space and the lower space are not connected, the piston assembly pushes the air into the second pipeline, and when the piston assembly moves upward, the upper space and the lower space are connected;
• a connecting rod, a lower end of the connecting rod is connected with the piston assembly, and an upper end of the connecting rod is inserted out of the pump;
• a handle, is fixedly disposed at the upper end of the connecting rod;
• a liquid storage tank, the upper cover is hermetically disposed at an upper end of the liquid storage tank, and a region of the upper cover corresponding to the liquid storage tank has a fourth through-hole;
• a third pipeline, an end of the third pipeline is connected with the third through-hole,
• and another end of the third pipeline is connected with the fourth through-hole;
• and
• a fourth pipeline, an end of the fourth pipeline is disposed at an inside lower end of the liquid storage tank, and another end of the fourth pipeline is inserted out of the upper cover;
• wherein the drawing or adding liquid machine comprises a foundation, a lower end of the pump and a lower end of the liquid storage tank both are hermetically and fixedly disposed at the foundation, the upper cover has a locating part, and the locating part hermetically cooperates with an upper end of the pump.