JP2013136187A - Ballpoint pen tip and ballpoint pen using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ballpoint pen tip capable of stably giving a pressure force to a ball, in which the ball makes a close contact with an inner wall surface of the tip end part when not in use, and to provide a ballpoint pen using the same.SOLUTION: In the ballpoint pen tip, the ball is pressed to the inner wall surface of the tip end part by a coil spring arranged in the rear of the ball. The tip end part of the coil spring includes: a straight part which is extended toward the ball; a folded part which is extended to be folded from the straight part; and a bent part which is continued to the straight part and the folded part, and is extended in a substantially vertical direction to the shaft core of the ballpoint pen tip. The bent part is abutted with the rear end part of the ball.

Description

  In the present invention, the tip of the tip is caulked inward so that a part of the ball protrudes from the tip tip edge and is rotatably held, and the ball is held by the coil spring disposed behind the ball. It is related with the ball-point pen tip formed by pressing on the inner wall surface.

  Conventionally, the structure of a ballpoint pen provided with a coil spring that presses the ball is well known and disclosed in Japanese Patent Application Laid-Open No. 10-329475, “Ballpoint Pen” and the like.

  A coil spring is arranged at the rear end of the ball, and the ball is brought into close contact with the inner wall surface of the tip of the tip by the pressing force of the coil spring, and a gap is formed between the ball and the inner wall of the tip of the tip by the writing pressure at the time of writing. Ballpoint pen tips having a valve mechanism to form are well known, and Japanese Patent Application Laid-Open No. 2000-158869 “Ballpoint Pen Tips” describes that even if the straight part of the coil spring moves, the straight part does not close the ink circulation groove. A structure is disclosed.

  Further, in a ballpoint pen tip provided with a valve mechanism at the tip end, Japanese Patent Application Laid-Open No. 2006-198835 “Ballpoint Pen Tip” discloses that the tip ball has a ball tip to prevent defects such as writing defects due to burrs in the straight part of the coil spring. It is disclosed that a contact ball is disposed at the rear end, and the contact ball is pressed against the tip ball by a coil spring.

Furthermore, in Japanese Patent Application Laid-Open No. 08-11478, an applicator is provided with a bent portion obtained by bending a straight portion of a coil spring, and the ball is pressed against the inner wall surface at the tip of the chip by the bent portion. A ballpoint pen tip is disclosed.
"JP 2000-158869 A" "Japanese Patent Laid-Open No. 2006-198835" "Japanese Patent Laid-Open No. 08-11478"

  However, in Patent Document 1, the wire diameter of the coil spring is as small as φ0.1 mm to φ0.3 mm, and there is a problem that the straight portion closes the ink circulation groove. Further, in Patent Document 2, there is a problem that the number of parts increases and the straight portion of the coil spring moves in the radial direction or the like and deviates from the center of the contact ball and presses. As a result, the contact ball However, there was a problem of not pressing the center of the writing ball. Furthermore, Patent Document 3 does not solve the problem that the straight portion and the folded portion of the coil spring move in the radial direction and deviate from the center of the ball and are pressed.

  In view of the above-mentioned patent document, when the wire diameter of the straight portion of the coil spring is increased, the volume of the coil spring with respect to the volume of the ink circulation hole is increased, and a passage for ink to flow out corresponding to the outflow of ink is provided. There is a problem that the ink cannot be secured, and there is a possibility that sufficient ink outflow from the tip of the tip may not be obtained at the time of writing.

  In view of the above problems, the present invention provides a ballpoint pen tip that can apply a stable pressing force to the ball and a ballpoint pen using the same in a ballpoint pen tip in which the ball is in close contact with the inner wall surface of the tip end portion when not in use. Is.

  In order to solve the above problems, the present invention has an ink circulation hole provided in the center of the bottom wall of the ball holding chamber and an ink circulation groove extending radially from the ink circulation hole in the chip body, By placing the ball on the wall and caulking the tip of the tip inward, a part of the ball protrudes from the tip of the tip and is held rotatably, and by the coil spring disposed behind the ball, In a ballpoint pen tip formed by pressing a ball against the inner wall surface of the tip end portion, a straight portion extending toward the ball at a tip portion of the coil spring, a folded portion extending so as to be folded back from the straight portion, and the straight A bent portion extending in a direction substantially perpendicular to the axis of the ballpoint pen tip, and the bent portion is brought into contact with the rear end of the ball And wherein the door.

  In addition, a wear-resistant coating layer is provided on the surface of the coil spring.

  Furthermore, the ballpoint pen refill is formed by mounting the ballpoint pen tip directly on the tip of the ink storage cylinder or via a chip holder, and directly storing the ink for the ballpoint pen in the ink storage cylinder. The ink for use contains at least fine particles.

  According to the first configuration of the present invention, in the ballpoint pen tip, at the tip of the coil spring, a straight portion extending toward the ball, a folded portion extending so as to be folded from the straight portion, and the straight portion and the folded portion. A bent portion that extends in a direction substantially perpendicular to the axis of the ballpoint pen tip, and abuts the bent portion on the rear end of the ball, so that the pressing force to the ball is reduced. In addition to being stable, ink can be smoothly supplied to the ball during writing. This is because the gap between the wire rods or the valley between the wire rods extends to the ball in the bent portion, and the ballpoint pen ink flows through the gap or valley.

  Further, since the bent portion can be bent with respect to the straight portion and the folded portion, a more stable pressing force can be obtained by a synergistic effect of the spring property of the coil portion of the coil spring and the spring property of the folded portion. Can be obtained.

  It is important that the coil spring of the present invention is formed by coiling from one coil wire and folding and bending the straight portion. This is because, for example, when coiled with two coil wires, the coil spring in the chip, particularly the coil part, has the same diameter, the same free length, and the same pressing force when attached. This is because there is a possibility that the volume of the ink increases and the ink flowability decreases. In consideration of ink supply to the ball, it is preferable to provide a gap between the wires in the bent portion.

  The present invention also includes a straight portion extending toward the ball, a folded portion extending so as to be folded back from the straight portion, a straight portion and a folded portion, and a straight portion extending from the straight portion to a tip portion of the coil spring. The shape is not particularly limited as long as the bent portion is provided continuously with the folded portion and provided with a bent portion extending in a direction substantially perpendicular to the axis of the ball-point pen tip, and the bent portion is in contact with the rear end portion of the ball. However, if the length of the bent portion in the radial direction is less than 50% of the ink circulation hole diameter, the folded portion moves due to the rotation of the ball during writing, and it is difficult to obtain a stable pressing force. If it exceeds, the bent portion may come into contact with the ink circulation hole and may not move back and forth smoothly. Therefore, the radial length of the bent portion is 50% or more and 95% or less with respect to the ink circulation hole diameter. Preferably, 70% or more, 90 The following are most preferred.

  In addition, the pressing force of the coil spring that presses the ball is most preferably set to 5 gf to 50 gf, preferably 10 gf to 30 gf, and 15 gf to 25 gf in consideration of writing feeling and ink leakage. The pressing force of the ball according to the present invention can be measured by the force required to contact the bottom wall of the ball holding chamber or the ball seat from the state of contact with the inner wall of the tip end portion. The clearance in the longitudinal direction of the ball can be appropriately selected depending on the ink viscosity and composition, but is preferably 5 μm to 60 μm. If the pressing force of the coil spring that presses the ball is 5 gf to 50 gf, ink leakage will occur. Considering 10 μm to 40 μm is most preferable.

  According to the second configuration of the present invention, the wear resistance coating layer is provided on the surface of the coil spring, and by suppressing the wear of the coil spring by the ball, the change of the ball pressing force due to the coil spring is suppressed, A stable writing feeling can be obtained.

As the wear-resistant coating layer used in the present invention, diamond-like carbon (DLC), tungsten disulfide (WS ₂ ), molybdenum disulfide (MoS ₂ ), titanium nitride layer (TiN) and the like are conventionally known. A wear-resistant coating layer can be used as appropriate. In addition, the method for coating the wear-resistant coating layer is not particularly limited, and examples thereof include vacuum deposition, ion deposition, physical vapor deposition, chemical vapor deposition, vacuum arc deposition, and the like. It may be a coating layer. In particular, among the above-mentioned wear-resistant coating layers, it is most preferable to use diamond-like carbon (DLC) in consideration of lubricity.

  Further, according to the third configuration of the present invention, the above-described ball-point pen tip is mounted directly on the tip of the ink storage cylinder or via a chip holder, and the ink for the ball-point pen is directly stored in the ink storage cylinder. In this ballpoint pen refill, when the ballpoint pen ink contains at least fine particles, good handwriting and feel can be obtained. This is because the fine particles enter between the ball and the bent portion due to the gap between the wires in the bent portion or the valley between the wires, so that the lubricity is improved and the fine particles in the bent portion are like a cushion. This is considered to increase the repulsive force, easily maintain the ink layer between the ball and the bent portion, and enhance the wear suppression effect.

  The fine particles described above are not particularly limited, and examples thereof include inorganic pigments, organic pigments, processed pigments such as pigments, organic fine particles, inorganic fine particles, and the like. Specifically, the pigments include carbon black, pearl pigments, fluorescent pigments, Examples thereof include phosphorescent pigments, complementary color pigments, microcapsule pigments, and specific examples of the fine particles include resin fine particles such as acrylic, silicone, and polyethylene, fine alumina particles, and fine silica particles. The size of the particles is 0.001 μm to less than 10 μm, preferably 0.001 μm to 5 μm on a volume basis. The shape of the fine particles is most preferably a true sphere or a substantially true sphere. The content of the fine particles is preferably 0.1 to 15% by mass with respect to the total amount of the ink composition. In addition, it is preferable to make the magnitude | size of the said fine particle smaller than the clearance gap between the wire materials in the said bending part. The size of the fine particles in the present invention means an average size to the last, and shows an average particle size in the case of a substantially spherical shape, and can be obtained by a centrifugal sedimentation method or a laser diffraction method.

  The present invention was able to provide a ballpoint pen tip capable of applying a stable pressing force to the ball and a ballpoint pen using the same in a ballpoint pen tip in which the ball is in close contact with the inner wall surface of the tip end portion when not in use. .

It is the figure made into the principal part expanded sectional view which abbreviate | omitted one part which shows the ball-point pen tip of Example 1. FIG. It is an expanded sectional view of the coil spring in FIG. It is the figure seen from the 90 degree direction in FIG. It is a figure which shows the manufacture process of the coil spring of Example 1. FIG. It is an AA expanded sectional view in FIG. It is a figure which shows the ball-point pen using the ball-point pen tip of Example 1. FIG. It is an expanded sectional view of the coil spring of Example 2. It is a figure which shows the manufacture process of the coil spring of Example 2. FIG. It is BB expanded sectional drawing in FIG.

  A ballpoint pen tip 1 of Example 1 shown in FIGS. 1 to 5 includes an ink circulation hole 5 in the center of a ball holding chamber 3 of a chip body 2 made of a stainless steel wire, and an ink extending radially from the ink circulation hole 5. A ball seat 4 having a curvature of the ball and a substantially curvature is provided on the bottom wall in which the flow groove 7 is formed, and a ball 8 having a diameter of 0.7 mm made of tungsten carbide cemented carbide is placed on the ball seat 4. By crimping the tip end portion 2A inward, a part of the ball 8 is rotatably held so as to protrude from the tip end edge of the tip, and a coil spring 9 is disposed behind the ball 8 to dispose the ball-point pen tip 1. It has gained.

  Specifically, the ball-point pen tip 1 is made of one stainless steel wire having a diameter of 0.15 mm, a straight portion 9A, a close contact portion 9D at the rear end of the straight portion 9A, and a coiled coil portion behind the straight portion 9A. A coil spring 9 having 9E is disposed. Specifically, as shown in FIG. 4, the straight portion 9 </ b> A positioned substantially at the axial center of the coil spring 9 is folded back (XX) by a certain length, and a folded portion 11 </ b> B is provided. Thereafter, the straight portion 9A and the folded portion 9B are bent (YY) in a direction substantially perpendicular to the axial center of the coil spring, and the bent portion 9C connected to the straight portion 9A and the folded portion 9B is provided. Form. The bent portion 9C is brought into contact with the rear end portion of the ball 8, and a part of the straight portion 9A and the folded portion 9B is located in the ink circulation hole 5, and the tip of the folded portion 9B is connected to the ink circulation hole 5. It is located and arranged (not shown) at the rear end. The straight portion 9A and the folded portion 9B are provided in contact with each other, and the radial length H of the bent portion 9C is 80% of the inner diameter of the ink circulation hole 5.

  The coil spring 9 is restricted from moving backward by caulking the rear end of the chip body 2 inward. With such a configuration, when not in use, the ball 8 is in close contact with the inner wall of the tip end portion 2A, and is a valve mechanism that provides a gap between the ball 8 and the inner wall of the tip end portion 2A by writing pressure during writing. The pressing force of the coil spring 9 that presses the ball 8 was 15 gf.

  Further, by turning the straight portion 9A and forming the folded portion 9B, the inflection portion R of the folded portion 9B has a rounded shape, and the coil spring 9 is subjected to the writing pressure when it is disposed in the chip. When moving back and forth (in the direction of arrow F in FIG. 1 and in the opposite direction), it becomes difficult to get caught in the chip.

FIG. 6 shows a ballpoint pen 10 in which the ballpoint pen tip 1 of the first embodiment is attached to the tip of the ink containing cylinder 11. The ink containing cylinder 11 contains a pigment having an average particle diameter of 0.3 μm, AR-G2 (stainless steel 40 mm 2 ° rotor), 20 ° C., shear rate 500 sec ^{− The} ballpoint pen 10 is obtained by directly containing the oil-based ballpoint pen ink 12 having a viscosity of 2000 mPa · s (25 ° C.) and the grease-like ink follower 13.

  When writing on the paper surface using this ballpoint pen 10, the ballpoint ink 12 in the ink containing cylinder 11 is supplied from the rear hole 7 of the ballpoint pen tip 1 to the ball 8 and the ball holding chamber 3 through the ink circulation hole 5 and the ink circulation groove 6. Is done. This ball-point pen ink 12 is moved by the ball pressure to the ball seat 4 side by the writing pressure, creating a gap between the inner wall of the tip end portion 2A and the ball 8 by the vertical clearance, and writing to the outside through this gap. can do. At this time, since the ball-point pen ink 12 from the ink circulation hole 5 is supplied to the ball 8 through the valley portion T of the bent portion 9C, the ink can be supplied smoothly.

  FIGS. 7 to 9 show other examples of coil springs. The coil spring 19 is the same as in Example 1 except that a lubricating coating layer J made of DLC (diamond-like carbon) is provided on the surface of the coil spring 19 and that the straight portion 19A and the folded portion 19B are provided apart from each other. Thus, the coil spring 19 is obtained.

  Specifically, the coil spring 19 is made of one stainless steel wire having a diameter of 0.15 mm, a straight portion 19A, a close contact portion 19D at the rear end of the straight portion 19A, and a coiled coil portion 19E behind the straight portion 19A. And have. As shown in FIG. 8, the coil spring 19 has a straight portion 19A of the coil spring 19 folded back (XX) by a predetermined length and provided with a folded portion 19B. Thereafter, the straight portion 19A and the folded portion 19B are bent (YY) in a direction substantially perpendicular to the axis of the coil spring 19, and a bent portion 19C connected to the straight portion 19A and the folded portion 19B is provided. It is formed.

  Although not shown, in the ballpoint pen using the coil spring 19, since the ink for the ballpoint pen is supplied from the ink circulation hole to the ball 8 through the gap S of the bent portion 19C, the ink can be supplied more smoothly. it can.

  Further, by providing a lubricating coating layer J made of DLC (diamond-like carbon) on the surface of the coil spring 19, the contact resistance with the ball 8 and the ink circulation hole can be reduced, and the wear of the coil spring 19 is suppressed and stabilized. And a smooth ball rotation can be obtained.

  In the present embodiment, for convenience, the rear end portion of the chip is crimped inward to hold the coil spring, but the method of holding the coil spring is not particularly limited, such as holding it in contact with the chip holder. Further, in this embodiment, since wear due to the rotation of the ball can be suppressed, a ball seat is provided on the bottom wall of the ball holding chamber as a preferred form for convenience. However, a shape without the ball seat may be used.

  Furthermore, in this embodiment, for the sake of convenience, the wear-resistant coating layer is provided only on the coil spring, but the wear-resistant coating layer is provided on the surface of the ball and / or the bottom wall of the ball holding chamber to provide a ball seat. It is preferable to suppress such wear.

    The type of ink for the ballpoint pen of the present invention is oily, water-based, etc., and the ink viscosity is not particularly limited, but if the viscosity at the time of writing is low or the ink consumption per 100 m is large, the ink Since it is difficult to suppress leakage and handwriting drying, the effect of the present invention is remarkable. Specifically, the ink can be suitably used for a ballpoint pen having an ink consumption of 30 mg or more under 50000 mPa · s or less under a condition of a shear rate of 500 sec-1 in an environment of 20 ° C. The ink consumption was measured on a JIS P3201 writing paper A under the conditions of a writing angle of 65 ° and a writing load of 100 g at a writing speed of 4 m / min. The average value of the ink consumption per 100 m was determined as the ink consumption per 100 m and measured.

  The ball-point pen tip of the present invention is not particularly limited, such as the type of ink and the ball diameter, and thus can be widely used as a ball-point refill and can be suitably used as a ball-point pen tip used for a knock-type ball-point pen.

DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Tip body 2A Tip end 3 Ball holding chamber 4 Ball seat 5 Ink flow hole 6 Ink flow groove 7 Rear hole 8 Ball 9, 19 Coil spring 9A, 19A Straight portion 9B, 19B Folded portion 9C, 19C Fold Curved part 10 Ballpoint pen 11 Ink receiving cylinder 12 Ballpoint pen ink 13 Ink follower T Valley part S Gap J Lubrication coating layer

Claims (3)

The chip body has an ink circulation hole provided in the center of the bottom wall of the ball holding chamber, and an ink circulation groove extending radially from the ink circulation hole, the ball is placed on the bottom wall, and the tip of the chip is By caulking inward, a part of the ball protrudes from the tip of the chip and is rotatably held, and the ball is pressed against the inner wall surface of the tip of the chip by a coil spring disposed behind the ball. In the ballpoint pen tip, a straight part extending toward the ball, a folded part extending so as to be folded back from the straight part, and the straight part and the folded part are provided continuously at the tip part of the coil spring, A ballpoint pen tip comprising: a bent portion extending in a direction substantially perpendicular to the axis of the tip, wherein the bent portion is brought into contact with a rear end portion of the ball. The ballpoint pen tip according to claim 1, wherein a lubricating coating layer is provided on a surface of the coil spring. A ballpoint pen refill in which the ballpoint pen tip according to claim 1 or 2 is mounted directly on the tip of an ink storage cylinder or via a chip holder, and ink for ballpoint pen is directly stored in the ink storage cylinder. The ballpoint pen contains at least fine particles in the ballpoint pen ink.

Images