JPH0558089A - Manufacture of ball-point pen tip - Google Patents

Abstract

PURPOSE:To provide a method wherein a center hole and a radial groove are formed in the seat of a ball receiver and then a pressing tool having the same conical shape as the seat is pressed against the radial groove so as to push down the opening of said groove, so that delivery characteristics of ink can be improved, while writing performance relating to the rotation of a ball is maintained. CONSTITUTION:The outer surface 5 of a tip member A is pressed down by a holder 6 to press the surface 5 by means of a pressing tool 7 against a ball receiving part 1 of the ball-point pen tip member A wherein a center hole 2 and a radial groove 3 are formed. The pointed end 8 of the tool 7 has the same conical shape as the part 1, but the pointed end angle has an angle of 118 deg. in consideration of repulsion near the center hole of the part 1. When the pressing tool having a conical shape whose end angle is slightly smaller than the angle of the receiving part, which has an angle of 120 deg., is pressed down in such a manner that the groove 3 is fully pressed down, the width of the opening of the groove 3 is made smaller as the groove 3 is pressed down. The groove width of the opening of the groove 3 is made smaller by about 0.03 mm after the pressing of the tool 7.

Description

Detailed Description of the Invention

[0001]

[Industrial application] A ball that holds a ball rotatably
A method of manufacturing a ball-pen tip having a hole receiving seat, a central hole, and a radial groove communicating with the central hole, wherein the ball receiving seat has an opening of the central hole and an opening of the radial groove. And a method for manufacturing a ball-point pen tip having

[0002]

2. Description of the Related Art Conventionally, as a ball pen tip, Japanese Patent Laid-Open No. 58-82532 discloses that "a ball receiving seat surface is spherically machined so that the ball can be smoothly rotated ..."
As disclosed, for the purpose of smoothing the rotation of the ball, a ball-pointing seat portion of the ball-pen tip is pressed with a pressing tool having a spherical tip or is arranged on the ball-receiving seat. There has been one in which a metal ball is pressed to form a mirror surface state (a state with a small surface roughness) on the ball receiving seat portion.

[0003]

DISCLOSURE OF THE INVENTION In the above ball pen, the ball receiving seat portion and the ball gripped by the seat portion.
If the shape of the ball and the shape of the ball are almost the same, it becomes difficult for the ink that also acts as a lubricant to enter between the ball receiving seat and the ball, and as a result, resistance to rotation of the ball occurs. There was something that happened.

In contrast to such a ball pen, the ball receiving seat having a conical shape has a ball receiving seat and a ball receiving seat.
The ink becomes a line contact, and ink as a lubricant can exist between the two.

For these reasons, the ball receiving seat has a conical shape, and the ball and the ball receiving seat are in line contact with each other. It is possible to add good writing quality to the rupen. However, during this pressing, the radial groove portion opened in the ball receiving seat portion may be partially or entirely widened.

As described above, in the case where the opening of the radial groove is widened, the capillary force is weakened in this opening, which causes a problem in ink dischargeability.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to the manufacture of a metal ball pen tip having a ball receiving seat for rotatably holding a ball, a central hole, and a radial groove communicating with the central hole. A method of manufacturing a ball-point pen tip, wherein the ball receiving seat portion has an opening portion of the central hole and an opening portion of the radial groove portion, wherein after forming the central hole and the radial groove portion, -A pressing member having a conical tip portion substantially equal to the ball receiving seat portion and having a mirror surface is pressed against the surface of the ball receiving seat portion, and at least the surface of the ball receiving seat portion. A method for manufacturing a ball-point pen tip is characterized in that a mirror-like state is formed on the surface and the opening of the radial groove is narrowed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example will be described below with reference to the drawings.

The member shown in FIG. 1 is formed by subjecting a stainless steel columnar member or a pipe-shaped member to cutting work, forging deformation or the like, and
By molding the base receiving portion 1, the central hole 2, and the radial groove portion 3,
The ball pen tip member A is used.

Here, the ball receiving seat portion 1 has an angle of about 120 degrees, and the radial groove portion 3 formed by broaching is about 0.06 mm at the opening portion 4. It has a groove width of.

As shown in FIG. 2, the outer surface 5 of the ball pen tip member A is pressed by the gripping tool 6 against the ball receiving seat portion 1 of the ball pen tip member A having the center hole 2 and the radial groove portion 3 formed therein. Pressing is performed by the pressing tool 7. Here, the tip end portion 8 of the pressing tool 7 has a conical shape that is substantially the same shape as the ball receiving seat portion 1, but the tip portion angle is near the center hole of the ball receiving seat portion 1. The repulsion is calculated to be 118 degrees.

Here, in pressing the pressing tool having a slightly sharp tip cone shape at an angle of the ball receiving seat of 120 degrees, if the pressing is performed to such an extent that the entire radial groove 3 is pressed down, The width of the opening of the radial groove is reduced to the same extent as a whole. The groove width of the opening of the radial groove portion 3 after pressing the pressing tool 7 is reduced to about 0.03 mm.

Here, as shown in FIG. 2, the diameter of the pressing portion of the pressing tool 7 is made slightly larger than the diameter of the ball receiving seat portion 1, and the shoulder portion 10 has a smooth corner. In addition, the side wall 9 of the ball receiving seat 1 may have a mirror-finished state. Thus, if not only the ball receiving seat portion 1 but also the side wall 9 are mirror-finished, the ball contacts not only the ball receiving seat portion 1 but also the side wall 9 in a linear state. The ball can rotate uniformly even when the tip of the ball pen is inclined with respect to the writing surface. Here, the mirror surface of the pressing tool 7 has a surface roughness of 0.2 μm or less.

[0014]

According to the method of manufacturing a ball-pen tip of the present invention, the inner hole of the member for the ball-pen tip is subjected to cutting or forging deformation to form a conical ball-receiving seat portion and this ball-receiving seat portion. -After forming a central hole and a radial groove opening in the ball receiving seat, a pressing tool having a conical tip end substantially equal to the ball receiving seat is pressed so that the entire opening of the radial groove is pressed down. The entire radial groove can be reduced in width, and while maintaining the writing quality regarding the rotation of the ball,
Ink dischargeability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a ball pen tip after processing the inside of a ball receiving seat portion.

FIG. 2 is a cross-sectional view showing a step of pressing the pressing portion against the ball receiving seat portion.

[Explanation of symbols]

 A ball pen tip member 1 ball receiving seat 2 center hole 3 radial groove 4 opening 5 outer surface 6 gripping tool 7 pressing tool 8 tip 9 side wall 10 shoulder

Claims (1)

[Claims] 1. A method of manufacturing a metal ball-pen tip having a ball receiving seat for rotatably holding a ball, a center hole, and a radial groove communicating with the center hole. In the method for manufacturing a ball-point pen tip having the opening of the central hole and the opening of the radial groove, the ball receiving seat is substantially equal to the ball receiving seat after forming the central hole and the radial groove. A pressing tool having a conical tip and having a mirror surface is pressed against the surface of the ball receiving seat to form a mirror surface on at least the surface of the ball receiving seat. A method for manufacturing a ball-point pen tip, characterized in that the opening of the radial groove is narrowed.