JP3623915B2 - Ballpoint pen manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ballpoint pen, and more specifically, a ballpoint pen provided with a valve mechanism for preventing ink leakage and preventing ink drying by urging a back surface of a transfer ball held inside a tip of a chip by a coil spring. It relates to a manufacturing method .
[0002]
[Prior art]
In a conventional ballpoint pen, a structure using a coil spring for holding a ball, more specifically, a valve mechanism that urges a transfer ball in a chip by a coil spring to closely contact the inward tip edge of the chip, Many are known such as JP-A-7-251592, JP-A-9-226288, JP-A-7-12280, and JP-A-8-216586.
In general, coil springs are manufactured by specialist spring manufacturers, but are formed by supplying coil wire to a coiling machine or forming machine, and the coil wire is applied to the machine during high-speed coiling by the coiling machine. In order to prevent the occurrence of catching breakage, the coil wire is plated for the purpose of improving lubricity.
[0003]
In the coil spring for holding the ball of the ballpoint pen, a stainless steel extra fine wire is used as the coil wire, and the wire diameter of the coil wire may be 0.2 mm or less. In this case, the surface of the coil wire W It was essential to form a nickel plating layer M on the substrate (see FIG. 3).
The coil spring is disposed in the chip or in a joint between the chip and the ink storage tube and is always in contact with the ink.
[0004]
[Problems to be solved by the invention]
However, although the conventional ballpoint pen is presumed to be caused by the nickel plating layer of the coil spring, the ink may deteriorate over time and cause problems such as writing wrinkles and writing errors.
That is, it is presumed that the long-term contact between the coil spring and the ink corrodes the nickel plating on the surface of the coil spring and the nickel sulfide dissolves into the ink and reacts with the ink to increase the ink viscosity. .
In particular, when the ink is a water-based ink having a so-called shear thinning viscosity, a phenomenon of writing wrinkles or non-writing is observed.
[0005]
An object of the present invention is to provide a ballpoint pen manufacturing method that solves the above-mentioned problems in view of the above-described conventional circumstances, prevents deterioration of ink over time, and has excellent writing performance without writing curling or non-writing. To do.
[0006]
[Means for Solving the Problems]
In the first invention, in the ballpoint pen manufacturing method in which the back surface of the rotatable transfer ball held inside the tip end of the chip is urged by the coil spring, the coil spring is a coil having a plated layer formed thereon. The plating layer is peeled off after being formed from a wire.
Further, in the second invention, the plating layer is a nickel plating layer, and the coil wire after molding is immersed in a nitric acid-based or sulfuric acid-based solvent, and the nickel plating layer is eluted in the solvent. Features.
Furthermore, the third invention is characterized in that ultrasonic waves are applied to the solvent.
Furthermore, in the fourth invention, the coil spring includes a pressing portion in which the free end of the coil on the tip side extends straight along the axial center, and the tip of the pressing portion contacts the transfer ball. The coil spring is configured to be in contact with each other, and is chamfered as deburring on the outer periphery of the distal end surface of the pressing portion.
The coil spring is limited in its shape as long as the transfer ball can be biased, such as a shape in which the entire length is formed in a coil shape, or a shape in which the tip side that contacts the transfer ball is formed in a straight shape. is not.
The tip includes not only the tip of the ballpoint pen tip but also the tip of the ballpoint pen refill.
[0007]
The coil spring is manufactured by forming a coil spring with a coiling machine or the like and performing a predetermined heat treatment when using a coil wire (coated coil wire) having a plating layer on the surface in order to improve workability and productivity. After that, the plating layer is peeled off and used after post-treatment such as washing. The coil wire in that case is generally a fine wire made of stainless steel (SUS304, SUS316).
Diameter of the upper Symbol coil wire is may be those exceeding the 0.2 mm, preferably used fine wire or ultrafine bare wires of 0.01 to 0.2 mm.
[0008]
According to the present invention, the coil spring is loaded and incorporated in the tip of the ballpoint pen without a nickel plating layer on the surface of the coil spring, so that the plating component remains in the ink even if the coil spring is in contact with the ink for a long time. It does not melt into
[0009]
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described. FIG. 1 shows a first example, and is an enlarged sectional view of a tip 1 of a ballpoint pen or a ballpoint pen refill.
The chip 1 has a substantially cylindrical shape obtained by processing a metal bar such as white or stainless steel, and a ball house 2 is formed inside the tip. A transfer ball 3 is rotatably held in the ball house 2. An ink passage 5 is opened behind the ball house 2 through an ink introduction hole 4.
[0010]
An ink storage tube 6 or the like is connected to the rear side of the chip 1, and ink 7 stored in the ink storage tube 6 is supplied into the ball house 2 through the ink passage 5 and the ink introduction hole 4.
The ink 7 is a gel ink having a so-called shear thinning viscosity. Specifically, the ink 7 is a water-based ink that has a high static viscosity but flows out with a decrease in viscosity due to rotation of the transfer ball 3 during writing.
[0011]
A coil spring 10 is inserted into the chip 1 from the rear end side, and the rear end portion of the coil spring 10 is hooked by a receiving member 8 that is fixed to the rear end portion of the chip 1, and the front end is the transfer ball 3. It is loaded so as to be in contact with the back surface of the urine.
[0012]
The coil spring 10 includes a pressing portion 10a in which the free end of the coil on the tip side extends straight along its axis, and the tip of this pressing portion 10a is allowed to loosely penetrate the ink introduction hole 4. It is brought into contact with the transfer ball 3. As a result, the tip of the pressing portion 10a elastically presses the transfer ball 3 by the elasticity of the coil spring 10 so as to be in close contact with the inward leading edge 1a of the chip 1, that is, the inward leading edge 1a of the chip 1. And the transfer ball 3 constitute a valve mechanism so that the ink 7 in the chip 1 is not ejected when not in use, and the ink is prevented from drying.
The coil spring 10 is obtained by cutting the pressing portion 10a to a predetermined length, and performing chamfering such as a so-called glass polishing method as deburring on the outer periphery of the cut end surface.
[0013]
The coil spring 10 is formed by using a coil wire W made of stainless steel (SUS304, SUS316) having a wire diameter of 0.01 to 0.2 mm, but the surface thereof has no nickel plating layer. Specifically, the coil spring 10 is manufactured as follows.
[0014]
When the coil wire W to which the nickel plating layer M is applied is used When the coil spring is formed using the coated coil wire W that has been subjected to nickel plating as shown in FIG. 3, heat treatment (300 ° C., 3 minutes), and then the surface nickel plating layer M is peeled off. That is, a large number of coil springs are accommodated together in a nitric acid-based or sulfuric acid-based solvent, and the nickel plating layer M is eluted with the solvent to be peeled off from the wire.
Specifically, the nickel plating layer M is suitably peeled off by a peeling treatment in which a nitric acid solution having a concentration of 1 to 10 vol% is used as a solvent and a large number of coil springs 10 are immersed at a solvent temperature of 60 to 90 ° C. Removed).
The immersion time in the peeling treatment varies depending on the concentration and temperature of the solvent. In the above range, about 1 to 10 minutes is sufficient, and if the immersion time may be long, the concentration and temperature of the solvent are further increased. It can also be set low. Moreover, immersion time can be shortened by applying an ultrasonic wave to the said solvent.
A large number of coil springs taken out from the solvent are then subjected to post-processing steps such as washing and drying to complete the coil spring 10.
[0015]
In the case of using the bare coil wire is it decrease the productivity of coiling molding.
[0016]
Next, FIG. 2 shows a second embodiment in which the shape of the coil spring is different. Since the chip 1 is substantially the same as the case of the first embodiment, the description is omitted by attaching the same reference numerals for the sake of convenience. To do.
The coil spring 20 is loosely penetrated into the ink introduction hole 4, and a small-diameter spring portion 21 that presses the transfer ball 3 at its tip, and a large-diameter spring portion 22 that is integrally formed on the rear side of the small-diameter spring portion 21. It consists of.
The small-diameter spring portion 21 has a coil outer diameter that is smaller than that of the large-diameter spring portion 22 on the rear side, and has an end turn portion 21a in which the coils are in close contact with each other on the tip side.
[0017]
The coil spring 20 abuts the end winding portion 21a of the small-diameter spring 21 against the back surface of the transfer ball 3, thereby elastically pressing the transfer ball 3 and bringing it into close contact with the inward leading edge 1a of the chip 1. The inward leading edge 1a of 1 and the transfer ball 3 constitute a valve mechanism.
Then, the coil spring 20 is also, as described above, when forming the coil spring by using a coating coil wire W is to a process for separating the nickel plating layer M on the surface after the molding, the surface of its The chip 1 is loaded without the nickel plating layer.
[0018]
Thus, since the coil springs 10 and 20 are loaded in the tip of the ballpoint pen without the nickel plating layer M on the surface thereof, the coil springs are in contact with the ink 7 having shear thinning viscosity for a long period of time. However, the plating component does not dissolve into the ink 7 and prevents the ink from being altered.
The coil springs 10 and 20 are made of stainless steel and contain nickel (Ni). However, the surface of the coil springs 10 and 20 becomes an alloy in the manufacturing process of the wire, and the surface is oxidized by chromium (Cr). Since the coating is formed, the component nickel of the coil wire does not melt into the ink 7.
[0019]
In the above embodiment, as the coil spring, the first embodiment provided with a straight pressing member on the tip side and the second embodiment including the large-diameter spring portion and the small-diameter spring portion have been described, but the present invention is not limited thereto. For example, the shape of the transfer ball is not limited as long as the transfer ball can be urged, for example, a conical shape having a reduced diameter from the rear side to the tip side.
The coil springs 10 and 20 have been described in the case where the entire length of the coil springs 10 and 20 is loaded in the chip 1. It is also possible to arrange the joint and the chip as in Japanese Patent No. 226288.
[0020]
【The invention's effect】
According to the present invention, since the coil spring is arranged without a plating layer such as nickel on the surface thereof, the plating component does not melt into the ink even if it is in contact with the ink for a long time. It is possible to prevent the occurrence of wrinkles and writing errors by preventing deterioration and deterioration over time such as increase in ink viscosity.
When the coil wire is made of stainless steel, stripping the nickel plating layer coated on該線material after the coil spring forming, the length of the writing performance of the ballpoint pen to remove adversely affect nickel component on the quality of the i ink Good period can be maintained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment in which a chip 1 of a ballpoint pen (including a ballpoint pen refill) of the present invention is enlarged.
FIG. 2 is a sectional view of the second embodiment.
FIG. 3 is a partially enlarged cross-sectional view of a coil spring using a coated coil wire.
[Explanation of symbols]
1: Chip 3: Transfer ball 7: Ink 10: Coil spring 20: Coil spring W: Coil wire M: Nickel plating layer

Claims (4)

In the ballpoint pen manufacturing method in which the back surface of the rotatable transfer ball held inside the tip end of the chip is urged by a coil spring.
  The method of manufacturing a ballpoint pen, wherein the coil spring is formed from a coil wire having a plated layer, and then the plated layer is peeled off. The plating layer is a nickel plating layer,
  2. The method of manufacturing a ballpoint pen according to claim 1, wherein the coil wire after forming is immersed in a nitric acid-based or sulfuric acid-based solvent, and the nickel plating layer is eluted in the solvent. 3. The ballpoint pen manufacturing method according to claim 2, wherein ultrasonic waves are applied to the solvent. The coil spring includes a pressing portion in which a free end of the coil on the tip side extends straight along its axis, and is configured to abut the tip of the pressing portion on the transfer ball,
  4. The ballpoint pen manufacturing method according to any one of claims 1 to 3, wherein the coil spring is chamfered as deburring on the outer periphery of the tip surface of the pressing portion.

Images