Liquid ink writing instrument

A liquid ink writing instrument comprising:

• a pen body for containing ink and constituting a principal part of the writing instrument;
• a writing element mounted on a head of the pen body;
• an ink absorber mounted on a rear end of the writing element;
• a fiber ink feeder mounted in the pen body penetrates through said ink absorber, a front end of which is contacted with the writing element, and a rear end is communicated with an ink cartridge formed by an inner cavity of the pen body;
• wherein,
• at least one air-liquid balancer is set in the pen body along an axial direction, the air-liquid balancer is installed between the fiber ink feeder and the pen body;
• there is one or more air-liquid exchange grooves penetrating an outer circumferential surface of the air-liquid balancer thereof and having a capillary attraction effect on the ink;
• there is an overflow groove on a radial surface of the air-liquid balancer, one end of which is in contact with the fiber ink feeder, and the other end of which is communicated with the air-liquid exchange groove;
• an interference fit is provided between an outer circumferential surface of the fiber ink feeder and an inner wall of the air-liquid balancer.