JP4132840B2 - Writing instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, welding of the writing instrument for writing tip, about a writing instrument, particularly applicable to gas leakage prevention and writing tip pressed break preventing the pressure ballpoint pen.
[0002]
[Prior art]
Ballpoint pens, especially those that contain pressurized gas, can simply drop the writing tip into the ink tube or tip holder due to the enclosed gas pressure, high temperature during circulation, or creep over time. There is sex. Further, there has been a problem of gas leakage due to minute scratches during assembly. Similarly, even with a normal writing instrument that is not a pressure pen, if a chip with a writing part is pressed in so that ink does not leak out, there will be a problem that the resin ink tube and the holder will crack. It was. In order to prevent this, it is made of other soft resin with poor performance, a peripheral groove is provided in the ink tube press-fitting part of the chip, or a special shape is used, and resin melted in the peripheral groove by ultrasonic waves is used. The holder is formed by inflow, or the holder is welded by ultrasonic heat generation to the tip of the shaft cylinder on which the writing tip is fitted so as to fix the writing tip with the chip holder that is fitted around the chip.
[0003]
[Problems to be solved by the invention]
When ultrasonic waves are used for welding, the writing tip is affected by the ultrasonic waves, and the ball held by the tip of the writing tip is dropped, the ink is bent, ejected, and the line is broken during writing. This causes damage to the writing part. Also, the ink tube fitting part of the writing tip cannot maintain the original strength due to external force, environmental temperature influence, creep deformation of the material itself, cracks, etc., chip falling off, ink leakage, the whole writing instrument generates heat, There is a problem that problems such as unstable welding occur.
[0004]
The present invention can appropriately weld only necessary portions without using ultrasonic waves between the writing chip and the ink tube or / and the chip holder, and can prevent the writing chip from dropping off or ink leakage. The purpose is to provide writing instruments .
[0005]
[Means for Solving the Problems]
The present invention includes a stainless steel writing tip having a writing portion to the writing instrument tip, and an ink tube ink therein hoarding, a writing instrument having a holding member for holding the writing tip,
The holding body is made of a resin material which is easily broken because there is no elongation of cyclic polyolefin, modified polyethylene terephthalate (modified PPE), polystyrene (PS) or the like whose tensile elongation (according to ASTM D638) is 20% or less. The holding body is formed in a substantially cylindrical structure in which the inner diameter of the front end portion in the longitudinal direction is a small diameter and the inner diameter of the rear end portion is a large diameter,
The holder is fixed by inserting the tip of the ink tube into the rear end of the large diameter,
The writing chip is inserted from the narrow tip end of the holder to the tip end of the ink tube inserted into the rear end of the holder ,
By performing electromagnetic induction heating on the part inserted into the holding body front end part and the ink tube front end part of the rear end part of the writing chip other than the front end part of the writing chip without using ultrasonic heating, by melting or softening the adhesion of the resin of the holding member distal end portion of its periphery to a rear end portion and an ink tube tip of the writing tip, said writing tip, and welded to the holding member distal end portion and an ink tube distal end portion of the surrounding ,
At the same time, the ink tube is covered with a hollow cylindrical inner shaft whose rear end is closed, and pressurized gas is sealed inside the inner shaft, and the tip of the inner shaft is fitted on the outer periphery of the holding body. a writing instrument that welded writing tip, characterized in that fixed to.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal cross-sectional explanatory view of a main portion tip portion of a pressurized ballpoint pen refill according to the first embodiment, and FIG. 2 is an explanatory drawing of a fitting and fixing state of a writing tip 10 and a joint (chip holding body) 12 in FIG. 3 is a longitudinal cross-sectional explanatory view of the tip of the gel ink ballpoint pen. The shaft cylinder to which the refill is attached is not shown.
[0007]
As shown in FIG. 1, the writing instrument according to the first embodiment of the present invention has a rear end portion 10c of a metal writing chip 10 externally fitted with a joint 12 which is a resin chip holding body and a front end of a resin ink tube 14. It is inserted in. And the inner shaft 16 closed at the rear end is fitted on the outer peripheral surface of the joint 12 to cover the writing tip central portion 10b from the tip portion of the inner shaft 16 and protect the writing tip 10. (So-called mouth plastic) 18 is fitted.
[0008]
The writing chip 10 holds the ball at the tip portion 10a which is a writing portion, and the outer peripheral surface portion of the center portion 10b is larger in diameter than the tip portion 10a and the rear end portion 10c.
The ink tube 14 has a hollow cylindrical shape and contains ink therein. The joint 12 has a slightly tapered general cylindrical structure, and the inner diameter of the central portion is smaller than that of the rear portion in a step shape. That is, in the large diameter portion 12a having a large inner diameter from the central portion to the rear portion in the axial direction of the joint 12, the distal end portion 14a of the ink tube 14 is inserted, and the inner peripheral portion of the distal end portion has a stepwise narrow diameter. The small-diameter portion 12b is externally fitted to a part of the writing tip rear end portion 10c. The tip of the small-diameter portion 12b has a stepped diameter, and the stepped portion on the rear side of the writing chip central portion 10b is inserted into the enlarged portion.
The ink tube 14 can be fixed to the chip 10 and / or the joint 12 in various ways such as mounting, adhesion, and welding so that the ink 23 inside does not leak.
[0009]
As shown in FIG. 1, an annular flange portion 12c is formed on the outer peripheral surface near the front end of the joint large-diameter portion 12a, and the inner shaft 16 that is externally fitted to the joint 12 abuts against the flange portion 12c. Is mounted and positioned. An annular protrusion 16 a is formed on the outer peripheral surface portion of the inner shaft 16.
The tip protector 18 as a whole has a shape along a substantially conical side surface. When the inner peripheral portion of the front end comes into contact with the outer peripheral surface of the central portion 10b of the writing tip 10, the tip protector 18 is prevented from coming off. The inner peripheral portion is fitted to the outer periphery of the inner shaft 16 while being in contact with the outer peripheral protruding portion 16a (the fitting portion is indicated by a symbol b). And it can fix by fitting with the joint 12 outer peripheral surface part and the inner shaft 16 inner peripheral surface part.
The writing chip 10 is connected to the ink tube 14 with the joint 12 interposed therebetween, and a pressurized gas is sealed in the inner shaft 16 to form a pressurized writing instrument.
In addition, the material of each part is polypropylene or polyethylene for the ink tube, and the joint 12 and the inner shaft 16 are gas barrier properties such as ethylene vinyl copolymer (EVOH), PET, nylon, PBT, POM, polyacrylonitrile, PEN. Each can be used in consideration of the point.
[0010]
Here, a predetermined portion 20 (at least a portion where the joint 12 small diameter portion 12b is fitted) 20 of the rear end portion 10c to be fitted into the joint 12 of the metal writing tip 10 of the writing instrument is heated, and this predetermined is performed by this heating. By melting the resin around the location, the predetermined location 20 of the writing chip 10 and the joint 12 around it are welded together.
In this case, since the front end portion 10a of the writing chip 10 is not heated and only the rear end portion 10c is heated, adverse effects such as discoloration, deformation, and deterioration due to heating of unnecessary portions can be prevented.
[0011]
The heating is preferably performed by electromagnetic induction heating of the predetermined portion 20 of the metal writing chip 10. If induction heating is used, only the target portion can be heated without causing problems such as ball drop due to vibration, ink deterioration, blow-out, poor welding, and overall unnecessary heating as in ultrasonic heating. In addition, as shown in FIG. 2, the induction coil 22 is installed with the induction coil 22 facing the predetermined location 20 of the metal writing chip 10, and the current is applied to the induction coil 22 to induce the induction coil 22 to the predetermined location 20. Only the predetermined portion 20 is heated by supplying an electric current.
It is also possible to heat the rear end of the writing chip 10 with a heating iron.
The writing chip 10 can be made of various metal materials as long as it is made of a metal that can be induction-heated. In particular, stainless steel that contains many components such as ferromagnetic Fe (iron) and Cr (chromium) inside and does not generate heat oxidation and rust is preferable. In addition, if at least the heating portion (predetermined portion 20) is made of stainless steel, the portions other than the heating portion can be made of other materials, and the range of material selection can be widened to reduce costs.
The writing instrument is effective in a pressurized ballpoint pen in which an inner cylinder is used as a sealed space and a pressurized gas such as pressurized air or nitrogen gas is sealed in the space. This is because, by the welding method, the predetermined portion can be easily and surely made a sealed structure that does not leak gas. Welding is also effective for preventing gas leakage due to vertical flaws attached during assembly.
[0012]
In the above-described embodiment, the writing tip is welded to the joint. However, the writing tip and the ink tube can be welded together or separately. Adhesion between the ink tube and the chip is tight and reliable, which is preferable in terms of preventing ink leakage.
[0013]
FIG. 3 is an explanatory view of a main part of a gel ink ballpoint pen according to the second embodiment of the present invention. The change from the first embodiment described above is that ABS, modified PPE, cyclic polyolefin, polycarbonate (PC), which is a material in which the writing instrument is non-pressurized, and the joint 12 is easily cracked by press fitting, and Polystyrene (PS), etc., which has a tensile elongation of 20% or less according to ASTM D638, can be prevented from cracking and chipping out by heat welding even if it is a resin that is very fragile because it does not stretch. . In the case of heat welding of the present invention, even if it is PS that is glassy and easily broken, if it is minute with almost no press-fitting allowance, or there is no press-fitting allowance and there is a gap, there is a weld that does not leak ink or gas Is possible. Further, although the shapes of the tip press-fitting portions of the tube 14 and the joint 12 are different, the present invention can be similarly applied. In addition, various things, such as a fountain pen, a sign pen, and a pipe pen, can be applied similarly.
[0014]
【The invention's effect】
The present invention is a stainless steel writing tip, since the welded to the holding member by electromagnetic induction heating without using the ultrasonic wave, the writing tip is not be affected by ultrasound, is holding the writing tip tip It is possible to prevent problems such as falling off of balls, ink deterioration, blowout, and line splitting during writing.
Also, the writing chip fitting part can maintain the original strength due to the external force, the influence of environmental temperature, creep deformation of the material itself, etc., and chip dropping, cracking of the press-fitting part, ink leakage, etc. occur. There is nothing.
In addition, since the front end portion of the writing tip is not heated and only the rear end portion is heated, there is an adverse effect on writing due to waste of heating of unnecessary portions, deterioration due to heating other than the welding necessary portions, and thermal deformation of the writing portion. It is possible to prevent adverse effects such as coming out.
In addition, cracking can be prevented by stress relaxation due to heating even in materials that cause cracks in normal press-fitting or materials that have little elongation.
In the present invention, the heating is induction heating of a predetermined portion of the stainless steel writing chip by an induction coil. Therefore , since the heating is not ultrasonic heating, it is possible to surely prevent the adverse effects due to ultrasonic heating as described above.
In addition, since the heated portion of the writing tip is made of stainless steel (particularly SUS430-based is preferred), even if the induction heating, there is no deterioration or the like occurs, efficient heating is, is reliable and good adhesion precision it can.
Further, when the writing tool is a pressure ballpoint pen, the surrounding tip of the writing chip is melted or softened and adhered to the rear end portion of the writing tip, and the peripheral portion of the writing tip Since the front end portion of the holder and the front end portion of the ink tube are welded, gas leakage can be completely prevented, and stable quality can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a main part of a pressure-type writing instrument according to a first embodiment of the present invention.
FIG. 2 is an explanatory view showing a state in which the writing tip of the first embodiment is fitted and welded to a joint.
FIG. 3 is an explanatory view of a main part of a gel ballpoint pen according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Writing tip 12 Joint 14 Ink tube 16 Inner shaft 18 Tip protector 20 Predetermined part (heating part)
22 induction coil 23 ink 24 pressurized gas

Claims (1)

And stainless steel writing tip having a writing portion to the writing instrument tip, and an ink tube ink therein hoarding, a writing instrument having a holding member for holding the writing tip,
The holding body is made of a resin material which is easily broken because there is no elongation of cyclic polyolefin, modified polyethylene terephthalate (modified PPE), polystyrene (PS) or the like whose tensile elongation (according to ASTM D638) is 20% or less. The holding body is formed in a substantially cylindrical structure in which the inner diameter of the front end portion in the longitudinal direction is a small diameter and the inner diameter of the rear end portion is a large diameter,
The holder is fixed by inserting the tip of the ink tube into the rear end of the large diameter,
The writing chip is inserted from the narrow tip end of the holder to the tip end of the ink tube inserted into the rear end of the holder ,
By performing electromagnetic induction heating on the part inserted into the holding body front end part and the ink tube front end part of the rear end part of the writing chip other than the front end part of the writing chip without using ultrasonic heating, by melting or softening the adhesion of the resin of the holding member distal end portion of its periphery to a rear end portion and an ink tube tip of the writing tip, said writing tip, and welded to the holding member distal end portion and an ink tube distal end portion of the surrounding ,
At the same time, the ink tube is covered with a hollow cylindrical inner shaft whose rear end is closed, and pressurized gas is sealed inside the inner shaft, and the tip of the inner shaft is fitted on the outer periphery of the holding body. writing implement welded a writing tip, characterized in that fixed to.

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