Disclosed are a knock type direct liquid pen refill assembly and a writing pen. The pen refill assembly comprises an ink cylinder assembly (100), a pen tip (200) and an elastic member (300). An ink guide core (150) is provided in the ink cylinder assembly. The pen tip (200) is arranged at one end of the ink cylinder assembly (100). An ink duct (210) is formed inside and passes through the pen tip (200). A ball member (230) is provided at an ink outlet end of the ink duct (210). The ink guide core (150) partially passes through the ink duct (210), and one end of the ink guide core (150) is abutted against the ball member (230). The elastic member (300) is sleeved at the periphery of the ink guide core (150) and positioned inside the ink duct (210). The elastic member is abutted against the ball member to exert a force, such that the ball member is closely attached to an inner wall of the ink outlet end, the ball member forms sealed contact with the inner wall of the ink outlet, and ink volatilization and leakage are avoided.

A method of manufacturing a metallic ball pen tip for a writing instrument comprising a feeding passage extending in an axial direction, the feeding passage reaching in a housing configured to receive a ball, the housing being defined by a cylindrical wall and a wall, the method comprising the steps providing a preform of the metallic ball pen tip comprising the feeding passage and the housing, the housing being defined by the cylindrical wall and a wall, machining the wall so as to obtain a stepped wall, broaching feeding grooves in the stepped wall and coining the stepped wall with a spherical die so as to obtain the ball seat, and a metallic ball pen tip obtained by the method.

A method of manufacturing a metallic ball pen tip for a writing instrument comprising a feeding passage extending in an axial direction, the feeding passage reaching in a housing configured to receive a ball, the housing being defined by a cylindrical wall and a wall, the method comprising the steps providing a preform of the metallic ball pen tip comprising the feeding passage and the housing, the housing being defined by the cylindrical wall and a wall, machining the wall so as to obtain a stepped wall, broaching feeding grooves in the stepped wall and coining the stepped wall with a spherical die so as to obtain the ball seat, and a metallic ball pen tip obtained by the method.

A writing instrument including a main body provided with a writing tip. The writing tip being supplied with ink by a free ink-type reservoir equipped with a pressure regulating device for regulating the pressure within the reservoir. The pressure regulating device includes at least one microfluidic valve.

A ballpoint pen tip comprises: a ball having a diameter of 0.5 mm or less; and a tip body, wherein the tip body has a ball holding chamber, a rear hole, an ink flow hole, and an ink flow groove opening to the ball holding chamber, and not reaching the rear hole. A ratio of an ink consumption per 100 m of handwriting to a diameter of the ball is 200 mg/mm or more and 800 mg/mm or less, and when a front end of the ink flow groove is set as a start point and a position of 0.3 mm rearward from the front end of the ink flow hole is set as an end point, a volume of a first space in the ink flow hole and the ink flow groove from the start point to the end point is 0.02 mm.sup.3 or more.

A ballpoint pen tip comprises: a ball having a diameter of 0.5 mm or less; and a tip body, wherein the tip body has a ball holding chamber, a rear hole, an ink flow hole, and an ink flow groove opening to the ball holding chamber, and not reaching the rear hole. A ratio of an ink consumption per 100 m of handwriting to a diameter of the ball is 200 mg/mm or more and 800 mg/mm or less, and when a front end of the ink flow groove is set as a start point and a position of 0.3 mm rearward from the front end of the ink flow hole is set as an end point, a volume of a first space in the ink flow hole and the ink flow groove from the start point to the end point is 0.02 mm.sup.3 or more.

A pen includes: an ink reservoir configured to store an ink; and a pen tip section including an ink application part configured to apply the ink to an ink application object. The ink application part of the pen tip section includes: a rigid tip made of a rigid material and having a hemispherical outer surface, an inner surface facing toward the ink reservoir, and a penetration part penetrating from the inner surface side to the outer surface side of the rigid tip; and at least one foam body filled in the penetration part at least on the side of the penetration part close to the outer surface side of the rigid tip, and provided with at least one air bubble formed to communicate from the outer surface side of the foam body to the inner surface side of the foam body.

A direct-liquid writing instrument includes a penholder, an ink feeder and a nib. One end of the penholder is provided with a writing portion, and the other end of the penholder is provided with an ink storage portion. The nib is partially inserted into the writing portion. The direct-liquid writing instrument also includes a first baffle and a second baffle that are spaced apart from each other to form an air barrier layer. The first baffle is in contact with the ink of the ink storage portion, and the second baffle is adjacent the writing portion. Additionally, the first baffle is provided with a first air-guiding channel, and a second air-guiding channel is provided between the second baffle and the ink feeder. The ink feeder passes through the first baffle, the air barrier layer, and the second baffle to deliver the ink to the nib.

A direct-liquid writing instrument includes a penholder, an ink feeder and a nib. One end of the penholder is provided with a writing portion, and the other end of the penholder is provided with an ink storage portion. The nib is partially inserted into the writing portion. The direct-liquid writing instrument also includes a first baffle and a second baffle that are spaced apart from each other to form an air barrier layer. The first baffle is in contact with the ink of the ink storage portion, and the second baffle is adjacent the writing portion. Additionally, the first baffle is provided with a first air-guiding channel, and a second air-guiding channel is provided between the second baffle and the ink feeder. The ink feeder passes through the first baffle, the air barrier layer, and the second baffle to deliver the ink to the nib.

A writing instrument including a main body provided with a writing tip. The writing tip being supplied with ink by a free ink-type reservoir equipped with a pressure regulating device for regulating the pressure within the reservoir. The pressure regulating device includes at least one microfluidic valve.