JP3355543B2 - Method of manufacturing ballpoint pen set - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip holder having a ballpoint pen tip holding a ball as a writing member at the tip thereof and protruding and fixed at a front portion of a bore, and a fiber bundle for guiding ink into the ballpoint pen tip. The present invention relates to a method for manufacturing a ballpoint pen tip set including a ballpoint pen tip, a chip holder, and an ink guide core by fixing the ink guide core to the ink guide core by ultrasonic welding.

[0002]

2. Description of the Related Art Heretofore, as a member for guiding ink contained in an ink tank into a ballpoint pen tip, a member using a fiber bundle of acrylic fiber, polyester fiber or the like as an ink guiding core has been known. Here, the position of the ink guide wick with respect to the ballpoint pen tip, which is the pen tip, should be strictly controlled, and if there is a space between the ink guide wick and the ballpoint pen tip,
This leads to poor ink connection to the pen tip, resulting in defects such as blurred handwriting. Conversely, if the ink guide core is pressed too strongly into the ballpoint pen tip, the space in the fiber The rate was locally reduced, making it difficult for ink to pass through, and eventually the handwriting was blurred due to poor ink connection to the pen tip. From the above, the ink guide core and the tip holder are welded and positioned and fixed,
Attempts have been made to make the positional relationship between the ballpoint pen tip and the ink guide core good and not to impair the good positional relationship due to vibration, impact or the like.

[0003] As a welding method, a thermal iron having a thin tip is used to point the iron between the rear portion of the chip holder and the ink guide core inserted into the inner hole of the chip holder, thereby melting and fixing both members simultaneously. , The so-called heat welding method, or making the tip of the ultrasonic horn thinner like the tip of the heat iron,
In order not to break the delicate processing inside the tip, the tip of the pen is kept in non-contact with other members, and while oscillating ultrasonic waves, the tip holder and the ink guide core inserted into the tip holder and the inner hole of the ballpoint pen tip There is known a so-called ultrasonic welding method in which an ultrasonic horn is pressed to melt and fix both members simultaneously.

[0004]

In the heat welding method using a hot iron, the temperature of the hot iron is easily affected by changes in the environment of the outside air and it is extremely difficult to keep the temperature constantly constant.
Therefore, there is a problem that it is difficult to perform processing with uniform welding strength, and the welding strength tends to be insufficient. If the temperature of the hot iron is raised or the welding time is lengthened so that the welding strength does not become insufficient, the amount of resin or the like that melts out increases, adversely affecting the connection relationship with other members such as the barrel, There is a risk that the ink path such as the ink guide core and the bore of the ballpoint pen tip may be adversely affected, and furthermore, the appearance becomes messy.

When the ultrasonic welding method is employed, the ultrasonic vibration cannot be applied only to a portion to be welded. That is, the ultrasonic vibration is also transmitted to the ballpoint pen tip connected to the chip holder, and sometimes destroys a delicate shape in the ball chamber holding the ball as a writing member. By making the tip of the ballpoint pen tip out of contact with other members, the effect of transmitting ultrasonic vibration can be suppressed somewhat.However, when ultrasonic vibration is transmitted to the tip end that prevents the ball from falling off, There has been a problem that the fore-edge portion expands or an outward force is applied to the ball itself, so that a ball detachment phenomenon easily occurs. When welding is performed by adjusting the ultrasonic vibration to such an extent that the ball does not come off, for example, by shortening the ultrasonic vibration application time, the desired welding strength cannot be obtained, and the product is dropped. There is a problem that the positional relationship between the ink guide core and the ballpoint pen tip changes due to the impact due to the vibration, the vibration at the time of transportation, and the like, and defects such as handwriting blur occur.

[0006]

That is, according to the present invention, ink is guided into a ball-point pen tip and a chip holder having a ball-point pen tip holding a ball as a writing member at the front end thereof, which is fixed at a front portion of a bore. In a method of manufacturing a ballpoint pen tip set for fixing an ink guide core made of a fiber bundle by ultrasonic welding, when applying ultrasonic waves to the tip holder and the ink guide core, the tip of the ballpoint pen tip is applied to an elastic member. The gist of the present invention is a method of manufacturing a ballpoint pen tip set characterized by being brought into contact with a ballpoint pen set.

[0007]

An embodiment will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a process of applying ultrasonic waves to a ballpoint pen tip set including a ballpoint pen tip 1, a tip holder 2, and an ink guide core 3. A ball-point pen tip 1 made of stainless steel is pressed into a hole 2a of a chip holder 2 made of polyacetal resin and fixed in a state where the tip protrudes, and then the hole of the chip holder 2 is extended to the inside of the ball-point pen tip 1. An ink guide core 3 which is a bundle of polyester fibers is inserted from 2a, and a ballpoint pen tip set including a ballpoint pen tip 1, a chip holder 2, and an ink guide core 3 is temporarily attached.

A stainless steel chip holder receiving jig 4 for positioning the temporarily attached ballpoint pen tip set
The spring 5 presses the rear part of the ink guide core with a force of 100 to 500 g in order to suppress poor contact between the ink guide core and the chip holder. Next, the tip holder 2 is fixed to the jig from the surroundings by a stainless fixing jig 6 so as not to swing, and the tip of the ballpoint pen tip 1 is made of an NBR plate ball pen having a thickness of 3 mm and a hardness of 80 °. It is brought into contact with the chip receiving jig 7. Finally, an ultrasonic welding machine 9 (USWP-200Z2 manufactured by Ultrasonic Industry Co., Ltd.)
A horn 8 (tip diameter: 1.2 mm) for applying ultrasonic vibration connected to the tip holder 2 is connected to the tip holder 2.
Ultrasonic vibration with an output of 200 W and a frequency of 28 KHZ is applied. The horn 8 is pierced while melting the tip holder 2 by ultrasonic vibration, and the horn 8 is
To complete the welding.

For comparison, a test was conducted by changing the time for applying the ultrasonic vibration. In addition, a test was performed when the material of the chip holder receiving jig 4 and the fixing jig 6 was changed.

Further, as a comparative example, a test in which the fixing jig 6 was not used, a test in which the ball-point pen tip receiving jig 7 was not brought into contact with the tip of the ball-point pen, and a test by a heat welding method were also performed. The samples used in each test are shown in (Table 1).

[0011]

[Table 1]

Test 1 The presence or absence of a ball was visually inspected for 100 samples of each of the above-mentioned Examples and Comparative Examples.

Test 2 The welding strength was determined by measuring the pull-out strength of the ink guide core with a push-pull gauge (Imada Co., Ltd., 0-5 kgf measurement) and comparing the stability of the welding strength (maximum value and minimum value).

Test 3 100 samples of each of the examples and comparative examples were assembled into a writing instrument and written with a writing tester, and the number of blurred handwritings was counted.

Test 4 The contact state between the ink guide core and the chip holder after dropping upward from a height of 1 m of the concrete floor was examined for 100 samples of each of the above Examples and Comparative Examples. The results of Tests 1 to 4 are shown in (Table 2) and (Table 3).

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

As described above, according to the method for manufacturing a ball-point pen tip set of the present invention, a uniform, stable and high-strength welded product can be obtained without the ball coming off during ultrasonic welding. .

[Brief description of the drawings]

FIG. 1 is a schematic view showing a step of applying ultrasonic waves.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Tip holder 2a Medium hole 3 Ink guide core 4 Tip holder receiving jig 5 Spring 6 Fixing jig 7 Ballpoint pen tip receiving jig 8 Horn

Claims (1)

(57) [Claims] 1. A tip holder having a ball-point pen tip holding a ball as a writing member at a tip thereof and fixed at a front portion of a bore, and an ink guide core made of a fiber bundle for guiding ink into the ball-point tip. In the method of manufacturing a ballpoint pen tip set fixed by ultrasonic welding, when applying ultrasonic waves to the chip holder and the ink guide core,
A method of manufacturing a ballpoint pen tip set, wherein the tip of the ballpoint pen tip is brought into contact with an elastic member.