JP2006334866A - Ball-point pen tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball-point pen tip, which is excellent in ink followability regardless of a kind and viscosity of an ink. <P>SOLUTION: In a ball holding chamber at a ball-point pen tip, a ball is rotatably held and, at the center of the bottom wall of the ball holding chamber, provided are: an ink flowing hole communicating with an inner hole at the rear end part of the tip; and ink flowing grooves each having a near U-shaped cross section and radially extending from the ink flow hole but not arriving to the inner hole of the rear end part of the tip. A joining part angle between the outermost wall surface from the ink flowing hole of the ink flowing groove and the bottom wall surface is set at least at 150° and not more than 180°, or the bottom wall surface of the ink flowing groove is a circular arcuate surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ballpoint pen tip formed by holding a ball rotatably in a ball holding chamber at the tip of the tip.

  Conventionally, a ball-point pen tip having an ink circulation groove communicating with an ink circulation hole at the center of the bottom wall of the ball holding chamber is well known. In such a ball-point pen tip, an ink circulation groove of a type that extends radially from the ink circulation hole and does not reach the inner hole at the rear end of the chip, as in Japanese Utility Model Publication No. 7-31382, “Ball Pen” is well known.

In such a ballpoint pen tip having an ink circulation groove that extends radially from the ink circulation hole and does not reach the inner hole at the rear end of the chip, Japanese Patent Application Laid-Open No. 8-207482 “Metal chip for ballpoint pen” includes an ink circulation hole. A ball-point pen tip is disclosed in which the diameter of the ink and the length of the ink circulation hole are made to be a fixed ratio, and the ink is prevented from being rewritten after being left upward and the ink following property at the time of high speed writing is improved.
“Japanese Utility Model Publication No. 7-31382” "JP-A-8-207482"

  By the way, the type of ink circulation groove that extends radially from the ink circulation hole and does not reach the inner hole at the rear end of the chip has a substantially U-shaped cross section as disclosed in Patent Documents 1 and 2, The surface is generally L-shaped. As shown in FIGS. 8 and 9, these ink circulation grooves extend radially from the ink circulation holes 105 by abutting and pressing the tool 109 against the bottom wall 103 of the ball holding chamber 102 of the ballpoint pen tip 101. An ink circulation groove 106 having a length L that does not reach the inner hole 107 at the rear end of the chip is formed.

  The tool 109 for forming the ink circulation groove 106 generally has a tip angle of 90 degrees in consideration of durability and the like, and is therefore the most distant from the ink circulation hole 105 of the ink circulation groove 106. The angle α of the joined portion S5 between the outer wall surface 106a and the bottom wall 106b was 135 degrees and was formed with a steep slope.

  As a result of examining the ink circulation groove and the ink followability, the present inventor has found that the inclination angle in the longitudinal section of the ink circulation groove and the ink followability are closely related. This causes turbulence in the vicinity of the joint between the outer wall surface and the bottom wall surface that are farthest from the ink circulation hole in the longitudinal section when the writing instrument ink communicates with the ink circulation groove from the inner hole at the rear end of the chip. It is thought that it is because.

  An object of the present invention is to provide a ballpoint pen tip having excellent ink followability regardless of the type and viscosity of the ink.

  The present invention includes an ink circulation hole that rotatably holds a ball in a ball holding chamber at a tip end of the chip, communicates with an inner hole in a rear end portion of the chip at the center of the bottom wall of the ball holding chamber, and the ink A ball-point pen tip having an ink flow groove extending radially from the flow hole and does not reach the inner hole at the rear end of the chip and having a substantially U-shaped cross-sectional cross section, the most spaced from the ink flow hole of the ink flow groove The outer wall surface is formed in an inclined shape that decreases in diameter from the tip end toward the rear end, and the angle of the joint portion between the outer wall surface and the bottom wall surface that is farthest from the ink circulation hole is 150 degrees or more, It is 180 degrees or less.

  The outer wall surface of the ink circulation groove that is farthest from the ink circulation hole is formed in an inclined shape that decreases in diameter from the tip end toward the rear end.

  In addition, the outer wall surface and the bottom wall surface that are the farthest from the ink circulation hole of the ink circulation groove are formed on an inclined surface having no joint portion.

  In addition, an ink circulation hole that rotatably holds a ball in a ball holding chamber at the tip end of the chip, communicates with an inner hole in the rear end of the chip at the center of the bottom wall of the ball holding chamber, and the ink circulation hole In the ball-point pen tip having an ink circulation groove that extends radially from the tip and does not reach the inner hole at the rear end of the chip, the bottom wall surface of the ink circulation groove is an arcuate surface.

  In addition, the outer wall surface and the bottom wall surface that are the farthest away from the ink circulation hole of the ink circulation groove are arc-shaped surfaces having no joint portion.

  It was possible to provide a ballpoint pen tip having excellent ink followability regardless of the type and viscosity of the ink.

  Next, embodiments of the ballpoint pen tip and the ballpoint pen using the same according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.

  The ball-point pen tip 1 shown in FIGS. 1 and 2 has a ball 8 placed on the bottom wall 3 of the ball holding chamber 2 of the chip body, and the tip end edge 4 is caulked inward, so that the ball 8 can be rotated. I have a hug. The bottom wall 3 of the ball holding chamber 2 has an ink circulation hole 5 communicating with the inner hole 7 at the rear end of the chip, and extends radially from the ink circulation hole 5 to the inner hole 7 at the rear end of the chip. Four ink flow grooves 6 having a length L1 that do not communicate with each other are formed.

  As shown in FIG. 3, the ink circulation groove 6 has a tool 9 in contact with the bottom wall 3 of the ballpoint pen tip so that the cross section is substantially U-shaped and the vertical section is substantially L-shaped, and pressed (FIG. 3). Thus, the ink flow groove 6 is formed, and the angle α1 of the joint portion S1 between the outer wall surface 6a and the bottom wall surface 6b that is farthest from the ink flow hole 5 is formed at 150 degrees. .

  The conventional ball-point pen tip 101 shown in FIGS. 8 and 9 can be obtained by setting the angle of the joint S1 between the outer wall surface 6a and the bottom wall surface 6b farthest from the ink circulation hole 5 of the ink circulation groove 6 to 150 degrees. Since the angle α of the joint portion S between the outer wall surface 106a and the bottom wall surface 106b that is farthest from the ink circulation hole 105 of the ink circulation groove 106 is larger than 135 degrees (α <α1). When the writing instrument ink passes through the ink circulation groove 6 from the inner hole 7 at the rear end of the chip, it becomes difficult to cause turbulent flow in the vicinity of the joint S1, and the ink followability is improved.

  The ball-point pen tip 11 of Example 2 shown in FIG. 4 has an outer wall surface 16a farthest from the ink circulation hole 15 of the ink circulation groove 16 and is formed in an inclined shape whose diameter decreases from the tip end toward the rear end. The ball of the chip body is the same as in Example 1 except that the angle α2 of the joint portion S2 between the outer wall surface 16a and the bottom wall surface 16b farthest from the ink circulation hole 15 of the ink circulation groove 16 is set to 150 degrees. By placing the ball 8 on the bottom wall 13 of the holding chamber 12 and caulking the tip end edge 14 inward, the ball 8 is rotatably held, and the chip is placed on the bottom wall 3 of the ball holding chamber 2. An ink circulation hole 15 communicating with the inner hole 17 at the rear end, and four ink circulation grooves 16 extending radially from the ink circulation hole 15 and not communicating with the inner hole 17 at the chip rear end are L2. Forming a ballpoint pen tip 11 .

  By forming the outer wall surface 16a farthest from the ink circulation hole 15 of the ink circulation groove 16 into a slanted shape with a diameter decreasing from the tip end toward the rear end, In order to set the angle α2 of the joint portion S2 between the outermost wall surface 16a and the bottom wall surface 16b, which are farthest apart, to 150 degrees, the length L2 of the ink circulation groove 16 is set to the length L6 of the ink circulation groove 106 of the conventional ballpoint pen tip 101. Since the length of the ink circulation groove 16 can be easily set, for example, the ink circulation groove 16 can be formed without being deeply formed.

  The ball-point pen tip 21 of Example 3 shown in FIG. 5 is formed except that the outer wall surface 26a and the bottom wall surface 26b that are farthest from the ink circulation hole 25 of the ink circulation groove 26 are formed on an inclined surface without a joint portion. In the same manner as in Example 1, the ball 8 is placed on the bottom wall 23 of the ball holding chamber 22 of the chip body, and the tip end edge 24 is caulked inward to hold the ball 8 rotatably. An ink circulation hole 25 communicating with the inner hole 27 at the rear end of the chip is formed in the bottom wall 23 of the ball holding chamber 22 and extends radially from the ink circulation hole 25 and does not communicate with the inner hole 27 at the rear end of the chip. A ballpoint pen tip 21 is obtained by forming an ink distribution groove 26 having a length of L3.

  The outer wall surface 26a and the bottom wall surface 26b, which are the farthest from the ink circulation hole 25 of the ink circulation groove 26, are formed on an inclined surface having no joint (angle α3 = 180 degrees), so that the writing instrument ink is transferred to the rear end of the chip. Since the turbulent flow does not occur in the vicinity of the joint portion when passing through the ink circulation groove 26 from the inner hole 27 of the portion, the ink followability is further improved.

  Note that the angle of the joint portion between the outer wall surface and the bottom wall surface that are the farthest away from the ink circulation holes is 150 degrees or more because the effect of suppressing turbulence is reduced when the angle is less than 150 degrees. Further, the angle of 180 degrees is most preferable because turbulent flow does not occur at the joint.

  The ballpoint pen tip 31 of the fourth embodiment shown in FIG. 6 is the same as the first embodiment except that the bottom wall surface 36b of the ink circulation groove 36 is formed in an arcuate surface, and the bottom wall 33 of the ball holding chamber 32 of the chip body. The ball 8 is placed on the tip and the tip end edge 34 is caulked inward to hold the ball 8 in a freely rotating manner, in the bottom wall 33 of the ball holding chamber 32, and in the inner hole 37 at the rear end of the tip. A ball-point pen tip 31 is obtained by forming the ink circulation holes 35 that communicate with each other and four ink circulation grooves 36 that extend radially from the ink circulation holes 35 and that do not communicate with the inner holes 37 at the rear end of the chip and have a length L4. ing.

  By forming the bottom wall surface 36b of the ink distribution groove 36 in an arcuate surface, the writing tool ink passes through the ink distribution groove 36 from the inner hole 37 at the rear end of the chip as in the third embodiment. Turbulent flow is unlikely to occur in the vicinity of the joint S3 between the outer wall surface 36a and the bottom wall surface 36b farthest from the ink circulation hole 35. Further, by making the bottom wall surface 36b of the ink circulation groove 36 into an arcuate surface, even if the length L4 of the ink circulation groove 36 is the same as in the second and third embodiments and the prior art, the volume of the ink circulation groove 36 is increased. Since the amount of ink passing through the ink circulation groove 36 is large and the ink followability is further improved, it is preferable.

  In the ball-point pen tip 41 of Example 5 shown in FIG. 7, the outermost wall surface 46a and the bottom wall surface 46b that are the farthest away from the ink circulation hole 45 of the ink circulation groove 46 are formed in a continuous arc-shaped surface without a joint portion. Except for the above, the ball 8 is placed on the bottom wall 43 of the ball holding chamber 42 of the chip body in the same manner as in the first embodiment, and the tip end edge 44 is caulked inward, so that the ball 8 can be held freely. An ink circulation hole 45 communicating with the inner hole 47 at the rear end of the chip is communicated with the bottom wall 43 of the ball holding chamber 42, and extends radially from the ink circulation hole 45 and communicates with the inner hole 47 at the rear end of the chip. The four ink circulation grooves 46 having a length of L5 are formed to obtain the ballpoint pen tip 41.

  Further, the outer wall surface 46a and the bottom wall surface 46b farthest from the ink circulation hole 45 of the ink circulation groove 46 are formed in a continuous arc-shaped surface having no joint portion, so that the writing instrument ink is the same as in the third embodiment. However, no turbulent flow occurs when the ink passes through the ink circulation groove 46 from the inner hole 47 at the rear end of the chip. Further, by forming the arc-shaped surface, similarly to the fourth embodiment, the volume of the ink circulation groove 46 is increased even if the length L5 of the ink circulation groove 46 is the same as that of the second and third embodiments and the prior art. Therefore, it is preferable because the amount of ink passing through the ink circulation groove 46 is large and the ink followability becomes extremely good.

  The outer wall surface 46a and the bottom wall surface 46b farthest from the ink circulation hole 45 of the ink circulation groove 46 may be the same arc or may be different arcs. It may be a structure.

  In the present embodiment, for convenience, the ball seat is not formed, but the ball seat may be formed on the bottom wall of the ball holding chamber. Also, the shape and number are not particularly limited as long as the ink circulation groove extends radially from the ink circulation hole and does not reach the inner hole at the rear end of the chip.

  Can be implemented without limitation on ink type and ink viscosity, such as oil-based ink, shear-thinning ink, and water-based ink, and is particularly effective for shear-thinning ink and low-viscosity oil-based ink that are ejected on the paper surface during writing. Can be used.

It is the longitudinal cross-sectional view which abbreviate | omitted partially which shows the ball-point pen tip of Example 1. FIG. It is AA sectional drawing which abbreviate | omitted one part in FIG. It is a figure which shows the state before forming the ink distribution groove | channel in FIG. It is the longitudinal cross-sectional view which abbreviate | omitted partially which shows the ball-point pen tip of Example 2. FIG. It is the longitudinal cross-sectional view which abbreviate | omitted one part which shows the ball-point pen tip of Example 3. FIG. FIG. 6 is a partially omitted longitudinal sectional view showing a ball-point pen tip of Example 4. FIG. 10 is a partially omitted longitudinal sectional view showing a ballpoint pen tip of Example 5. It is the principal part expanded sectional view abbreviate | omitted in the conventional ball-point pen tip. It is a figure which shows the state before forming the ink distribution groove | channel in FIG.

Explanation of symbols

1, 11, 21, 31, 41, 101 Ball-point pen tip 2, 12, 22, 32, 42, 102 Ball holding chamber 3, 13, 23, 33, 43, 103 Bottom wall 5, 15, 25, 35, 45 , 105 Ink flow hole 6, 16, 26, 36, 46, 106 Ink flow groove 6a, 16a, 26a, 36a, 46a, 106a Outer wall surface 6b, 16b, 26b, 36b, 46b, 106b Bottom wall surface 7, 27, 37 , 107 Inner hole at the rear end of the chip 8 Ball 9, 109 Tool S, S1, S2, S3 Joint α, α1, α2, α3, Angle of joint

Claims (5)

A ball is rotatably held in a ball holding chamber at the tip of the chip, an ink circulation hole communicating with an inner hole in the rear end of the chip at the center of the bottom wall of the ball holding chamber, and a radial shape from the ink circulation hole A ball pen tip having a substantially U-shaped ink circulation groove that does not reach the inner hole at the rear end of the chip, and an outer wall surface that is the most spaced from the ink circulation hole of the ink circulation groove; A ballpoint pen tip having an angle of a joint portion with a bottom wall surface of 150 degrees or more and 180 degrees or less. 2. The ballpoint pen tip according to claim 1, wherein an outer wall surface of the ink circulation groove that is farthest from the ink circulation hole is formed in an inclined shape that decreases in diameter from the tip end toward the rear end. 3. The ballpoint pen tip according to claim 2, wherein an outer wall surface and a bottom wall surface that are farthest apart from the ink circulation hole of the ink circulation groove are formed on an inclined surface having no joint portion. A ball is rotatably held in a ball holding chamber at the tip of the chip, an ink circulation hole communicating with an inner hole in the rear end of the chip at the center of the bottom wall of the ball holding chamber, and a radial shape from the ink circulation hole A ballpoint pen tip having an ink circulation groove extending to the inner edge of the tip rear end portion and having a bottom wall surface of the ink circulation groove is an arcuate surface. The ball-point pen tip according to claim 4, wherein the outer wall surface and the bottom wall surface that are farthest from the ink circulation hole of the ink circulation groove are arc-shaped surfaces having no joint portion.

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