JP3221077B2 - Method for manufacturing ballpoint pen tip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The pressing force was applied by pressing pin ball BACKGROUND OF the ball protruding end portion protruding from the ball-point pen tip made of metal Borupe <br/>-chip was holding, pressing the bottom wall of the ball holding portion The present invention relates to a method for manufacturing a ballpoint pen tip that forms a spherical ball receiving seat portion by deformation.

[0002]

Hole portion including a ball holding portion of the Related Art Metal ballpoint pen tip is formed by the general cutting, countless cutting marks formed on the surface of the ballpoint pen tip inner wall after cutting, It is in a so-called rough state with many fine irregularities. When the inner wall of the ballpoint pen tip is thus roughened, smooth rotation of the ball is impeded. In view of this point, conventionally, a method of manufacturing a ballpoint pen tip that forms a ball receiving seat by pressing a ball with a pressing pin transfers the shape of the ball to the ball receiving seat,
The purpose is to form a ball receiving seat with a shape approximately the same as the ball, so that the ball is positioned to some extent during writing, and to make the surface condition of the contact portion between the ball receiving seat and the ball better than immediately after cutting. It was. Further, in this method, since the contact portion of the pressing pin that comes into contact with the ball is a flat surface, it comes into contact with the ball at a point or near a point.

[0003]

In the above method, the pressing force is concentrated on one point of the ball, and the ball is pressed.
There is a problem that deformation of the ball and a phenomenon that a part of the ball is chipped occur. Similarly, since the force is concentrated at one point even at the contact portion of the pressing pin, there is a problem in durability of the pressing pin. In addition, the contact position between the ball and the pressing pin varies, resulting in variations in the amount of projection of the ball from the tip of the ball pen tip and the dimensions of the ball receiving seat.
There was a problem that a ball pen tip of stable quality could not be obtained.

[0004]

SUMMARY OF THE INVENTION The present invention is, from the ball-point pen tip of a metal ball-point pen tip which is holding the ball
A method of manufacturing a ballpoint pen tip, wherein a pressing force is applied to a protruding tip portion of a protruding ball by a pressing pin to form a spherical ball receiving seat portion by pressing deformation on a bottom wall of the ball holding portion. A contact recess for contacting the ball is formed in the
The present invention provides a method for manufacturing a ballpoint pen tip, characterized in that a pressing force is applied to the ballpoint pen.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In each embodiment, basically the same parts are denoted by the same reference numerals.

Reference numeral 1 denotes a metal ball-point tip.
Reference numeral 2 denotes a metal ball, and 3 denotes a ball pressing pin. The ball 2 is held by the ball holding portion 4 of the ball pen tip 1. The ball pen tip 1 and the ball 2 form a ball.
The writing section of Lupen is configured. The pressing pin 3 is moved in the direction of the arrow (the direction A in the drawing) to press the ball 2, and the bottom wall 5 of the ball holding portion 4 is pressed by the ball 2 to be deformed by pressing. To form a spherical ball receiving seat portion 6 having substantially the same shape as that of FIG.

Here, as shown in FIG. 2, a ball contact recess 7 having a spherical shape substantially the same shape as the ball is formed in a portion of the pressing pin 3 which contacts the ball. . Press pin 3
The ball 2 comes into contact with the ball 2 and the ball 2 comes into contact with the pressing pin 3 by apparent upper surface contact. Thus, the pressing force of the pressing pin 3 can be efficiently transmitted to the ball 2. Therefore, the pressing force is not concentrated, the deformation and chipping of the ball are suppressed, and the durability of the pressing pin 3 is also improved. Further, since the ball 2 can be positioned with respect to the pressing pin 3 by the contact concave portion 7, if the positional relationship of the ball pen tip 1 with respect to the pressing pin 3 is managed, the ball formed on the ball pen tip 1 can be formed. The position of the ruler seat 6 can be managed.

As shown in the drawing, the contact recess 7 of the pressing pin 3 is not only a spherical recess which comes into surface contact with the ball 2, but also
A conical concave portion that makes circumferential line contact with the ball 2 can also be used.

The ball receiving seat portion 6 of the ball pen tip 1 formed by such a method is once pressed and deformed excessively by the ball and then slightly restored by the elastic force of the metal. The ball 2 and the ball receiving seat 6 are in line contact with each other. In the case of a low viscosity ink such as an aqueous ball pen ink having a viscosity of 2 to 5 centipoise, the ball 2
When the ball receiving seat 6 comes into line contact with the ball receiving seat 6, the movement of the ink in the ball holding portion 4 is smooth, and the writing feeling is improved.

The ball 2 is pressed while rotating the pressing pin 3 in the embodiment of FIG. 1 in the circumferential direction of the ball pen tip 1 (the direction of the arrow B in FIG. 1) by appropriate means. Since the ball 2 also rotates in conjunction with the rotation of the pressing pin 3, the ball
Rotational force is applied to the screw receiving seat 6 in addition to the pressing force. By fixing the ball pen tip 1 so as not to rotate, the ball receiving seat 6 is adhered and worn by rotation. As a result, the above-mentioned elastic force of the metal is suppressed at the contact portion of the ball receiving seat portion 6 with the ball 2, and the restoration after pressing hardly occurs. Therefore, by this processing, the ball 2 and the ball receiving seat 6 are brought into surface contact.

A ball in which the ball and the ball receiving seat portion are in surface contact.
Lupen tips are good for high viscosity inks such as oily ballpoint inks having a viscosity of 6,000 to 10,000 centipoise. In the case of ink having high viscosity to some extent, such as oil-based ball pen ink, when the ball and the ball receiving seat are in linear contact, the ink film is separated and the ball and the ball are separated. This causes contact between the metal members and the receiving seat portion, which gives the user a feeling of writing when writing. In addition, the amount of ink transferred onto the paper surface on the ball is reduced, and the ink follow-up property during writing is poor. As a result, the amount of ink transferred to the paper surface on the ball is reduced, and the writing line is blurred. According to the present embodiment, the balls 2 and
An ink film is formed in a minute gap between the two while being in surface contact with the ball receiving seat portion 6, so that a large amount of ink can be applied to the ball, and the ink followability in writing can be improved.

Here, as shown in FIG. 3, the rotational force applied to the ball is rotated in the direction perpendicular to the circumferential direction (the direction of arrow C in the drawing) in the direction of the arrow (the direction of arrow D in the drawing). Power can also be applied. Specifically, as shown in FIG. 4, the pressing pin 3 has a cylindrical contact body 9 in which a ball contact recess 7 is formed on the body 8 over the entire circumference. The ball contact recess 7 is brought into contact with the ball 2, and the entire periphery of the ball contact recess 7 is brought into contact with the ball 2 while pressing the ball 2 against the ball receiving seat 6. Then, the contact member 9 is rotated, and the entire pressing pin is further rotated in the circumferential direction with respect to the ball pen tip 1.

The shape of the ball seat 6 obtained by applying a rotational force as described above is shown in FIG. 3 and FIG. 5, which is an enlarged view of a portion I in FIG. Ball receiving seat part 6 which comes into contact with ball 2
Are formed with fine wear marks due to cohesive wear, and small protrusions 11 are formed at the end portions 10 as relief portions for strain due to plastic deformation.
Is formed. The projection 11 further increases the contact area between the ink and the ball, holds the ink film, smoothes the rotation of the ball, and improves the ink followability. be able to.

In the above, the ball pen tip 1, the ball pen
Although various metals can be used for the screw 2 and the pressing pin 3, alloys such as stainless steel and nickel silver are often used. Specifically, an iron alloy containing 20% of chromium and 2% of molybdenum is adopted as a ball-point tip.
Some adopt a tungsten carbide alloy containing 10% of cobalt. The ball pen tip 1, the ball 2, and the pressing pin 3 are more related to each other than the pressing pin.
It is preferable that the ball is hard and that the ball is harder than the ball pen tip.

[0015]

According to the present invention, the pressing force imparted by the pressing pin ball protruding end portion protruding from the ball-point pen tip made of metal baud <br/> Rupenchippu was holding the ball, the bottom wall of the ball holding portion In the method of manufacturing a ballpoint pen tip, which forms a spherical ball receiving seat portion by pressing deformation, a contact concave portion that contacts the ball is formed on the pressing surface of the pressing pin, and the ball is pressed against the ball while rotating.
Since the force is applied , deformation of the ball and chipping of the ball can be suppressed, the durability of the pressing pin can be improved, and the amount of protrusion of the ball from the ball pen tip and the ball can be prevented. suppressing variation in dimensional accuracy such as Le receiving seat to a minimum, volume of stable quality - Rupenchippu can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of the present invention.

FIG. 2 is a perspective view showing members used in the present invention.

FIG. 3 is a sectional view showing another example of the present invention.

FIG. 4 is a perspective view showing members.

FIG. 5 is an enlarged sectional view of a main part of a member manufactured according to the present invention.

[Explanation of symbols]

A Arrow indicating the pressing direction B Arrow indicating the rotating direction C Arrow indicating the rotating direction D Arrow indicating the rotating direction I Main part 1 Ball pen tip 2 Ball 3 Press pin 4 Ball holding part 5 Bottom wall 6 Bo -Ball receiving seat 7 Ball contact recess 8 Body 9 Contact body 10 End 11 Projection

Claims (1)

(57) [Claims] 1. A ball pressing force imparted by the pressing pin ball protruding end portion protruding from the ball-point pen tip of a metal ball-point pen tip which is holding, spherical ball by pressing deformation on the bottom wall of the ball holding portion In the method of manufacturing a ball-point pen tip that forms a receiving seat, a contact recess that contacts the ball is formed on a pressing surface of the pressing pin.
Applying pressing force to the ball while rotating together
Ballpoint pen tip manufacturing method which is characterized by that.