JP2002046384A - Ballpoint pen tip made of metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a writing satisfaction by reducing a ball sink of a pipe type ballpoint pen tip. SOLUTION: A metal fine tube is formed of an austenite stainless steel containing C of 0.03% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal ball-point pen tip, and more particularly to a ball-point pen tip using a pipe-shaped metal thin tube, and more particularly to a metal ball-point tip specifying a material of the metal thin tube.

[0002]

2. Description of the Related Art Conventionally, a metal thin tube in the form of a pipe has been used, and a ball receiving seat is formed by an inward projection which presses and deforms the vicinity of the front end of the metal thin tube inward. A metal ballpoint pen tip formed by inserting a ball in between and crimping the leading edge is used.

As such a thin metal tube, an austenitic stainless thin tube, particularly SUS304, has been generally used. In this SUS304, the content of C is 0.08%
Although described as below, the content was actually 0.03% or more. According to the classification of the ballpoint pen tip, in the invention described in JP-A-63-166596, a metal ballpoint pen tip made of stainless steel containing titanium three times or more by weight of carbon is disclosed.
In the invention described in JP-A-59-143694, the nickel content is 10.5 to 13.0% and the chromium content is 17.0 to 17.0%.
A metal ballpoint pen tip using a 19.0% austenitic stainless steel pipe is disclosed.

[0004]

One of the characteristics required for a ballpoint pen tip is the amount of ball sinking. Here, the sinking of the ball is a phenomenon in which the receiving seat gradually wears due to the friction generated between the rotating ball and the receiving seat, so-called play of the ball increases. When the amount of sinking of the ball increases, the gap between the ball and the opening at the tip of the tip increases, so that the supply amount of ink increases,
It was also the cause of bottling.

In particular, when a pigment ink is used as the ink, the pigment particles are insoluble in the solvent, and the particles are dispersed in the solvent in a suspended state. The presence of the particles increases wear of the receiving seat, and the ball sinking amount is made larger than that of the dye ink. Under such circumstances, ballpoint pen chips include a so-called bullet type and a pipe type.

[0006] Here, a bullet-shaped ballpoint pen tip means a ball house, an ink flow hole,
An ink circulation groove and the like were formed. This type of ballpoint pen tip is designed to reduce the size of the ink flow hole and the width of the ink flow groove, etc.
The area of the seat that is in contact with the ball has been increased. In addition, various measures have been taken to prevent the ball from sinking when the pigment ink is used.

On the other hand, a ball-point pen tip using a metal pipe has a lower receiving seat than a so-called shell-shaped ball-point pen tip because the receiving seat for the rotating ball is formed by an inwardly pressed projection. The area in contact with the ball is small, and the ball sinking due to wear is correspondingly large. Also, if you try to increase the area of the seat that is in contact with the ball, the amount of deformation due to the pressing deformation must be increased, which may cause deformation of the ball house, cracking of the inward projection, etc. I was

Therefore, according to the first aspect of the present invention, a ball receiving seat is formed by an inward projection which presses and deforms the vicinity of the distal end of the thin metal tube inward, and a ball receiving seat is provided between the ball receiving seat and the distal end. An object of the present invention is to reduce the amount of ball sinking in a metal ball-point pen tip formed by inserting a ball and crimping the leading edge. According to the second aspect of the present invention, a ball receiving seat is formed by pressing and deforming the vicinity of the distal end of the thin metal tube inward, and then a ball house is formed by cutting. It was intended to reduce the amount of ball sinking in a metal ballpoint pen tip formed by caulking.

The invention described in claim 3 is the first or second invention.
In addition to the object of the invention described above, it is an object to set a reasonable range between the diameter of the ball and the diameter of the inscribed circle of the inward projection. A fourth aspect of the present invention aims at defining a reasonable number of inward projections in addition to the object of the first, second or third aspect of the invention. A fifth aspect of the present invention has the object of enabling use regardless of the material of the ink used, in addition to the objects of the first, third, and fourth aspects of the invention.

[0010]

In order to achieve the above-mentioned object, a first aspect of the present invention comprises a ball and a holder for holding the ball at a tip thereof, wherein the holder comprises a tip of a thin metal tube. In a metal ballpoint pen tip formed by forming a ball receiving seat by an inward projection that deforms the neighborhood inward by pressing the ball inward, inserting a ball between the ball receiving seat and the tip, and crimping the tip edge. The thin metal tube is formed of austenitic stainless steel having a C content of 0.03% or less.

The invention according to claim 2 comprises a ball and a holder for holding the ball at the tip,
The holder presses and deforms the vicinity of the distal end of the thin metal tube inward to form an inward protrusion, thereby forming a ball receiving seat, and then forming a ball house by cutting, and then putting the ball into the ball house. In a metal ball-point pen tip formed by caulking a tip end edge, the metal thin tube is formed of austenitic stainless steel having a C content of 0.03% or less.

The invention described in claim 3 is the first or second invention.
In addition to the configuration of the invention described above, when the diameter of the ball is A and the diameter of the inscribed circle of the inward projection is B, the relationship between A and B is 0.3 ≦ B / A ≦ 0.5. It is characterized by having done.
According to a fourth aspect of the present invention, in addition to the configuration of the first, second, or third aspect of the present invention, the inward protrusions are arranged at three locations that are almost equally distributed.

[0013] The invention according to claim 5 is the invention according to claims 1, 2, and 3.
Alternatively, in addition to the constitution of the invention described in 4 above, a pigment ink is used as the ink to be used. Here, in the case of a holder made of austenitic stainless steel SUS304, a ball made of cemented carbide, and a pipe-type ballpoint pen tip made of a combination of pigment ink, frictional heat is generated due to friction between the ball and the seat during writing, and It has been found that since C forms a carbide with Cr near the grain boundary, Cr is reduced near the grain boundary and further wear is promoted.

Therefore, the use of austenitic stainless steel having a low carbon content, which is a material that does not form carbides of Cr even when frictional heat is generated, as in the invention described in claim 1 or 2, reduces the formation of carbides. Therefore, there is no decrease in Cr, and a metal ballpoint pen tip with little wear can be formed. Here, as the low carbon content austenitic stainless steel, the content of C was 0.03.
% Or less, for example, SUS301L, SUS
304L, SUS304LN, SUS316L, SUS
316LN, SUS317L, SUS317LN, SU
S317J3L, SUS317J4L, SUS317J
5L and the like.

In addition, even if low-carbon stainless steel is used, the dimensional relationship between the inner projection and the ball, which is advantageous in sinking the ball, is provided as long as deformation of the ball house and cracking of the inner projection do not occur. Is the range described in claim 3.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a ballpoint pen tip used in the present invention will be described with reference to the drawings showing the manufacturing steps.
FIG. 1 is a sectional view showing the metal tube itself, and FIG. 2 is a partial sectional view showing a completed chip. FIG. 3 is a cross-sectional view showing a state in which a ball is put in the holder, FIG. 4 is a side view of the holder looking at the ball house, and FIG. 5 is an enlarged front view of the tip after crimping.

Here, the thin metal tube 10 shown in FIG. 1 is made of austenitic stainless steel having a C content of 0.03% or less. This metal tube 10 is
As shown in FIG. 2, the ball receiving seat 31 is formed by pressing and deforming the vicinity of the distal end of the thin metal tube 10 inward to form an inward projection 30, and then forming a ball house by cutting. The ball 20 is put into a ball house, and the tip edge is crimped to form a ball-point pen tip as a swaged portion 40.

In this case, first, three inward projections 30, 30, 30 are formed by inwardly deforming three places, which are almost equally distributed, from the tip of the thin metal tube 10 to an appropriate position. Next, the outer peripheral surface and the inner surface of the distal end portion of the inner protrusion 30 are processed by cutting. Thereafter, the ball 20 is positioned on the inward projection 30 from the distal end side of the thin metal tube 10, and the ball 20 is pushed to the opposite distal end side to slightly sink and harden the receiving seat 31.

Next, the tip edge is further swaged inward to form a swaged portion 40, thereby completing the ballpoint pen tip. Next, experimental results relating to the sink amount of the receiving seat 31 will be described using the present invention and the comparative example having such a shape. First, various members used in the experiment will be described. (Ball) A (diameter) = 0.38 mm Material: made of cemented carbide (chip) Example Metal tube size: 0.6 mm outer diameter x 042 mm inner diameter x 8 mm length Metal tube material: SUS316L (C: 0.017% Comparative Example Metal tube size: outer diameter 0.6 mm x inner diameter 0.42 mm x length 8 mm metal tube material: SUS304 (C: 0.067%) (ink) component carbon black 7.0% by weight ammonium styrene acrylate resin Group 3.0% by weight ethylene glycol 20.0% by weight Kari soap (lubricant) 0.4% by weight 1: 2-benzisothiazolone salt (preservative) 0.2% by weight aminomethylpropanol (pH adjuster) 0.3 Wt% Benzotriazole (rust inhibitor) 0.2 wt% Polyacrylate (acrylic synthetic polymer) 0.1 wt% Deionized water balance Viscosity Viscosity at 25 ° C .: 100 mPa · s The following values were used for the diameter (B) of the inscribed circle of the inward projection shown in FIG. B (diameter) = 0.10 mm (B / A = 0.26) 0.12 mm (B / A = 0.32) 0.15 mm (B / A = 0.40) 0.18 mm (B / A = 0) .47) 0.20 mm (B / A = 0.53) The experimental results were as shown in FIG. 1 by changing the material ratio and the value of “B / A”.

Here, "x" in "holder deformation"
Indicates a chip that has become unusable due to deformation of the ball house, cracking of the inward projection, etc. due to an excessively large amount of inward projection. The ball sinking amount is
It is displayed in the unit of “mm”, and if it exceeds 0.030 mm, it is treated as causing inconvenience in writing.

Further, a writing test for measuring such a sinking amount is performed using a writing tester conforming to ISO standard 14145-1, writing speed: 4.5 m / min, writing angle: 60 °, writing addition: 100 gf writing. Distance and method: After the test under the conditions of 1000 m continuous spiral writing, the amount of ball sinking was measured.

However, for a pen that became unwritable at a distance of less than 1000 m, the distance to the point at which writing was disabled and the amount of sinking at the time when writing was disabled are shown. In addition, if the holder was deformed and the writing test could not be performed, the amount of sinking of the ball is not described.

[0023]

[Table 1]

From these results, it was found that B
When the value of / A is the same, the content of C is 0.017%
It was confirmed that SUS316L of the No. 2 had a lower sink amount of the ball 20 than SUS304 having a C content of 0.067%. When B / A is 0.26, SUS316L having a C content of 0.017% also has a C content of 0.017%.
SUS304 with a content of 0.067% was also unable to write. This is due to the fact that the length of the projection as the inward projection 30 is too large, causing deformation of the ball house or cracking of the inward projection 30.

Therefore, from this experiment, it was found that B / A was 0.1.
If it is less than 30, it is highly likely that writing becomes impossible, and it is considered unsuitable as a ballpoint pen tip. In addition, according to Comparative Example 7, it can be seen that writing was impossible at 450 m of writing. This is because B / A is large,
That is, since the amount of protrusion of the inner protrusion 30 is small, the receiving seat 3
It is considered that the wear of No. 1 was large and the writing distance was reduced. In comparison, in Comparative Example 2, 1000
m, but the ball sinking amount was 0.034m
m. Although this was better than Comparative Example 7, it was evaluated as unsuitable because the ball sinking amount was too large.

As a result, it was found that the austenitic stainless steel having a low C content can reduce the amount of ball sinking as compared with the same type having a high C content. In addition, as for the range of C, 0.017% was used in the above experiment, but it was confirmed that 0.03% or less is preferable in consideration of other experiments.

Further, from the above experiment, B / A was also
It was confirmed that a value between 0.3 and 0.5 was suitable.
With respect to the inwardly protruding portion 30, the ball is not stable with two protruding portions, and if the number is four or more, the protruding length cannot be increased, so that the area of the receiving seat 31 is reduced. It proved to be suitable.

In the above experiment, the case where the pigment gel ink is used has been described. Of course, the use of the dye ink is expected to reduce the ball sinking amount. Also,
It has been confirmed that even when ink mixed with aluminum powder, such as gold or silver ink, is used, the same tendency as in the above experimental results is obtained.

[0029]

As described above, according to the first aspect of the present invention, the ball receiving seat is formed by the inward projection which presses and deforms the vicinity of the distal end of the thin metal tube inward. The ball sink amount is reduced in a metal ballpoint pen tip formed by inserting a ball between a seat and a tip and crimping the tip edge.

According to a second aspect of the present invention, a ball receiving seat is formed by pressing and deforming the vicinity of the distal end of the thin metal tube inward.
Thereafter, after forming a ball house by cutting, the ball is put into the ball house, and the tip of the tip is crimped to reduce the ball sinking amount in the metal ball-point pen tip. The invention described in claim 3 is the invention according to claim 1.
Or, in addition to the effects of the invention described in 2, the ratio of the diameter of the ball and the diameter of the inscribed circle of the inward projection is set.

According to the fourth aspect of the invention, in addition to the effects of the first, second or third aspect of the invention, a reasonable number of inward projections is defined. Further, the invention according to claim 5 is based on claims 1, 2,
In addition to the effects of the invention described in 3 or 4, it can be used regardless of the material of the ink used.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a thin metal tube itself.

FIG. 2 is a partial cross-sectional view showing a completed ballpoint pen tip.

FIG. 3 is a sectional view showing a state where a ball is put in a holder.

FIG. 4 is a side view of the holder as seen from the ball house.

FIG. 5 is an enlarged front view of a tip portion after caulking.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Metal thin tube 20 Ball 30 Inward projection 31 Receiving seat 40 Caulking part

Claims (5)

[Claims] 1. A ball and a holder for holding the ball at the tip thereof, the holder forming a ball receiving seat by an inward projection which presses and deforms the vicinity of the tip of the thin metal tube inward. In a metal ballpoint pen tip formed by inserting a ball between a ball receiving seat and a tip and crimping the tip edge, the metal thin tube is made of austenitic stainless steel having a C content of 0.03% or less. A metal ballpoint pen tip formed by: 2. A ball receiving device, comprising: a ball; and a holder for holding the ball at the tip. The holder presses and deforms the vicinity of the tip of the thin metal tube inward to form an inward projection. After forming a seat and then forming a ball house by cutting, a ball is put into the ball house, and a tip end edge is caulked to form a metal ball-point pen tip. A metal ball-point pen tip formed of austenitic stainless steel having a content of not more than 03%. 3. When the diameter of the ball is A and the diameter of the inscribed circle of the inward projection is B, the relationship between A and B is 0.3 ≦ B.
3. The metal ball-point pen tip according to claim 1, wherein /A≦0.5. 4. The metal ball-point pen tip according to claim 1, wherein the inward projections are divided into three places which are almost equally distributed. 5. The metal ball-point pen tip according to claim 1, wherein the ink used is a pigment ink.