JP2012000774A - Ballpoint pen tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ballpoint pen tip that can obtain stable ball rotation and amount of ink outflow by separately forming a ball seat at a different position in an axial direction.SOLUTION: The ballpoint pen tip has, in a tip body an ink circulation hole which communicates to a rear hole of tip body, and an ink circulation groove extending in the shape of a radiation from the ink circulation hole at a center of a bottom wall of ball holding chamber, holds rotatably part of the ball by projecting it from a tip leading edge by inserting the ball to the bottom wall, and caulking the tip end inside. The ballpoint pen tip is characterized in that the ball holding chamber has a first ball holding chamber, and a second ball holding chamber of diameter smaller than the first ball holding chamber at a rear part of the first ball holding chamber, and inserts the ball to the bottom walls of the first ball holding chamber and the second ball holding chamber, and forms the ball seat of substantially the same shape with the ball to bottom walls of the first ball holding chamber of the bottom wall of the second ball holding chamber, while holding the ball rotatably.

Description

  The present invention has an ink circulation hole formed in the center of the bottom wall of the ball holding chamber, and an ink circulation groove extending radially from the ink circulation hole in the chip body, and the ball is inserted into the bottom wall. Further, the present invention relates to a ballpoint pen tip that is configured such that a tip of a tip is caulked inward so that a part of a ball protrudes from the tip tip edge and is rotatably held.

  Conventionally, a ball is inserted into a ball holding chamber having an ink circulation hole in the center of the bottom wall and an ink circulation groove extending radially from the ink circulation hole, and the tip of the chip is caulked inward, thereby A ball-point pen tip is well known in which a portion is protruded from a tip end portion and is rotatably held.

  In such a conventional ballpoint pen tip, as disclosed in Japanese Patent Laid-Open No. 2000-71672 “ballpoint tip”, a ball seat substantially the same shape as the ball is provided on the bottom wall of the ball holding chamber, and wear resistance is high. Many ballpoint pen tips with improved performance have been proposed.

  In addition, the size of the ink distribution groove, particularly the size of the ink distribution groove, particularly the opening area of the ink distribution groove, affects the amount of ink supplied to the ball, as in the size of the ink distribution hole and Japanese Patent Application Laid-Open No. 2001-205968. It is.

JP 2000-71672 A JP 2001-205968 A

  However, the conventional ballpoint pen tip such as Patent Document 2 has a problem that the area of the ball seat that comes into contact with the ball is reduced when the opening area of the ink circulation groove is increased for the purpose of increasing the ink supply amount.

  On the other hand, if the area of the ball seat is simply increased, the process of forming the ball seat becomes difficult, and the deformation part that occurs when the ball seat is formed closes the ink circulation groove, so that the amount of ink supplied to the ball is reduced. There was a risk of significant reduction.

  The present invention has been made in view of these prior arts, and by forming the ball seats at different positions in the axial direction, stable ball rotation and ink outflow can be obtained. It is to provide a ballpoint pen tip.

  In order to solve the above problem, the present invention provides an ink circulation hole communicating with the rear hole of the chip body at the center of the bottom wall of the ball holding chamber, and an ink circulation extending radially from the ink circulation hole. A ball-point pen tip that has a groove, and a ball is inserted into the bottom wall and the tip end of the tip is crimped inward so that a part of the ball protrudes from the tip end edge and is held freely. The ball holding chamber has a first ball holding chamber and a second ball holding chamber having a smaller diameter than the first ball holding chamber behind the first ball holding chamber; The ball is inserted into the bottom walls of the first ball holding chamber and the second ball holding chamber to hold the ball rotatably, and the bottom wall of the first ball holding chamber and the second ball holding A ball seat having substantially the same shape as the ball is formed on the bottom wall of the chamber.

  The ball seat of the first ball holding chamber may include a diameter portion of a ball extending vertically from the axis of the chip body.

  According to the configuration of the first aspect of the present invention, the ballpoint pen tip includes the first ball holding chamber, the first ball holding chamber, and the first ball holding chamber located behind the first ball holding chamber. A second ball holding chamber having a small diameter, the ball is inserted into the first wall holding chamber and the bottom wall of the second ball holding chamber, the ball is rotatably held, and the first In order to form a ball seat substantially the same shape as the ball on the bottom wall of the ball holding chamber and the bottom wall of the second ball holding chamber, not only the area of the seat is increased, but also a position separated in the axial direction Since the ball seat is provided in the ball, the rotation of the ball is stabilized.

  In addition, by forming the first ball holding chamber and the second ball holding chamber, the space for storing ink can be formed at different positions in the axial direction, so that it is possible to obtain good ink ejection. Play.

  According to the configuration of claim 2 of the present invention, the ball seat of the first ball holding chamber includes the diameter portion of the ball extending perpendicularly from the axis of the chip body, so that the ball play is effectively prevented. Therefore, stable ball rotation can be obtained.

  The ballpoint pen tip of the present invention is most preferably made of a metal such as stainless steel, aluminum, brass or the like. The total area of the ball seat is not particularly limited, but is preferably 20 to 40% of the ball surface area.

  The present invention has been able to provide a ballpoint pen tip that can obtain a stable rotation of the ball and an ink outflow amount by forming the ball seats at different positions in the axial direction.

FIG. 3 is an enlarged vertical cross-sectional view of a main part in which a part of the ball-point pen tip of Example 1 is omitted. It is AA sectional drawing which abbreviate | omitted the ball | bowl in FIG. It is a figure which shows the 1st ball holding chamber and the 2nd ball holding chamber in FIG. 1 after manufacture. It is BB sectional drawing in FIG.

  The ball-point pen tip 1 of Example 1 shown in FIGS. 1 and 2 includes a tip body 2 made of stainless steel wire, a first ball holding chamber 3, and a first ball holding chamber 3 behind the first ball holding chamber 3. A second ball holding chamber 6 having a diameter smaller than that of the ball holding chamber 3, an ink circulation hole 9 in the center of the second ball holding chamber 6, and extending radially to communicate with the ink circulation hole 9, Eight ink flow grooves 10 that do not reach 11 are formed and communicated with the first ball holding chamber 3 and the second ball holding chamber 6, and the ball on the bottom wall 4 of the first ball holding chamber 3. A ball 12 made of tungsten carbide having a diameter of 0.7 mm is placed on the ball seat 8 on the bottom wall 7 of the seat 5 and the second ball holding chamber 6, and the tip end 2 a of the ball 12 is caulked inward to thereby form one of the balls 12. The part is held in a rotatable manner so that the part protrudes from the tip end edge of the chip.

  The ball-point pen tip 1 is formed by cutting a stainless steel wire having a diameter of 2.3 mm and a hardness of 230 Hv to 280 Hv into a desired length, and holding the first ball holding chamber 3 and the second ball holding as shown in FIGS. After producing the chamber 6, the ink circulation hole 9, and the rear hole 11, the ink circulation groove 10, the bottom wall 4 of the first ball holding chamber 3, and the bottom wall 7 of the second ball holding chamber 6 are hammered. Ball seats 5 and 8 having substantially the same shape as the ball are formed.

  A ball seat 5 of the first ball holding chamber 3 is formed from the bottom wall 4 of the first ball holding chamber 3 to the second ball holding chamber 6 as shown in FIG. A ball seat 5 formed on the bottom wall 4 of the first ball holding chamber 3 and the bottom wall 7 of the second ball holding chamber 6, formed at a position including the diameter portion (CL) of the vertically extending ball 12; The total area of 8 was 25% of the surface area of the ball 12. The clearance of the ball 12 in the front-rear direction was 10 μm.

  In addition, a writing instrument ink passage (not shown) at the time of writing leads from the rear hole 11 to the second ball holding chamber 6 through the ink circulation hole 9 and the ink circulation groove 10, and further to the ink circulation hole 9 and the ink. The circulation groove 10 and the second ball holding chamber 6 communicate with the first ball holding chamber 3 and flow to the tip end portion of the chip.

  The ballpoint pen tip of the present invention can be used without being limited to the ink used, and can be used regardless of the type of ink, such as oil-based ballpoint pen ink, water-based ballpoint pen ink, ink with shear thinning viscosity, and correction ink. Therefore, it can be widely used as a ballpoint pen tip using a ball as a writing medium.

DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Tip body 2a Tip 3 First ball holding chamber 4 Bottom wall 5 Ball seat 6 Second ball holding chamber 7 Bottom wall 8 Ball seat 9 Ink flow hole 10 Ink flow groove 11 Rear hole 12 Ball

Claims (2)

The chip body has an ink circulation hole communicating with the rear hole of the chip body at the center of the bottom wall of the ball holding chamber, and an ink circulation groove extending radially from the ink circulation hole, and the ball is placed on the bottom wall. A ballpoint pen tip that is inserted and caulked with the tip end of the tip inward so that a part of the ball protrudes from the tip end edge of the tip and is rotatably held. A ball holding chamber and a second ball holding chamber having a diameter smaller than that of the first ball holding chamber at the rear of the first ball holding chamber; The ball is held on the bottom wall of the ball holding chamber to hold the ball rotatably, and the bottom wall of the first ball holding chamber and the bottom wall of the second ball holding chamber have substantially the same shape as the ball. A ballpoint pen tip forming a ball seat. 2. The ballpoint pen tip according to claim 1, wherein the ball seat of the first ball holding chamber includes a diameter portion of a ball extending perpendicularly from an axis of the tip body.

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