JP5802449B2 - Ballpoint pen refill - Google Patents

Description

  The present invention relates to a ballpoint pen refill in which a tip holder is press-fitted and attached to the tip of an ink containing cylinder, and a tip of the tip holder is attached with a ballpoint pen tip that rotatably holds a ball.

  Conventionally, a ballpoint pen refill has been well known in which a tip holder is press-fitted and attached to the tip of an ink containing cylinder, and a tip of the tip holder is attached with a ballpoint pen tip that rotatably holds a ball. No. 198291 “Ball Pen Refill” and the like.

  By the way, in recent years, many ballpoint refills have been marketed for the purpose of improving writing quality and the like, and low-viscosity oil-based ballpoint pens and water-based ballpoint pens imparted with shear thinning. Such low-viscosity oil-based ballpoint pens and water-based ballpoint pens imparted with shear thinning have a high ink consumption, and therefore, a ballpoint refill with good ink followability is desired.

JP 2000-198291 A

  However, when the inner diameter of the rear hole of the chip holder is simply increased, as in Patent Document 1, the thickness of the chip holder is reduced at the fitting portion between the ink containing cylinder and the chip holder, and the fitting force may be reduced. In view of these problems, if the chip holder fitting part has a certain thickness, the moldability is poor and sink marks are likely to occur, and a gap occurs between the ink containing cylinder and the chip holder fitting part. Although it is necessary to increase the fitting force, there is a problem that the assembling property is lowered.

  The present invention has been made in view of these conventional techniques, and the problem of the present invention is that the ink followability is good, the chip holder and the ink storage cylinder are easily press-fitted, and the chip holder and the ink storage cylinder Another object of the present invention is to provide a ballpoint pen refill that is unlikely to cause ink leakage from a fitting portion with a simple structure.

In order to achieve the above object, the present invention provides a ballpoint pen refill in which a tip holder is press-fitted and attached to the tip of an ink containing cylinder, and a tip of the tip holder is attached with a ballpoint pen tip that rotatably holds a ball. A rear hole communicating with the ink containing cylinder is provided at the rear end of the chip holder, and a plurality of ribs projecting toward the axial center and extending in the longitudinal direction are provided at different positions in the circumferential direction on the inner wall of the rear hole. this, formed, the width of the rib, provided in equal width, and the circumferential clearance ribs between adjacent, with smaller toward the shaft center, the circumferential clearance ribs between which the proximity, 0 0.1 to 1.0 mm .

  The inscribed circle diameter of the rib may be increased toward the rear.

The rear hole is composed of a front hole and a rear hole having a larger inner diameter than the front hole, which is connected to the rear of the front hole, and the ribs are the front hole and the rear hole. And the thickness of the tip holder in the portion where the rib is not formed in the front hole portion and the rear hole portion is substantially the same.

  According to the configuration of claim 1 of the present invention, a rear hole communicating with the ink containing cylinder is provided at the rear end portion of the chip holder, and the inner wall of the rear hole protrudes toward the axial center and extends in the longitudinal direction. By forming multiple extending ribs at different positions in the circumferential direction, the ballpoint pen ink that flows from the ink receiving cylinder through the rear hole of the chip holder when the ink for ballpoint pen by writing consumes and follows, Ink can flow by the main flow flowing in the inscribed circle of the rib on the side and the side flow flowing between the ribs, the capillary action is easy to work, and the ink followability is enhanced.

  In addition, by forming a plurality of ribs extending toward the axial center in the rear hole at different positions in the circumferential direction, the volume of the space in which ink flows is larger than a chip holder having the same thickness as the rib. The amount of ink increases and the ink followability increases, and the phenomenon that the ballpoint pen ink in the ballpoint pen tip flows back to the ink containing cylinder side due to an impact such as when knocking or dropping occurs, that is, the phenomenon of ink incorporation has ribs. Thus, the wall surface resistance due to the increase in the contact area between the ballpoint pen ink and the tip holder can be suppressed. Furthermore, compared with a chip holder having the same thickness as the rib, the moldability is good and the effect of suppressing the occurrence of sink marks and the like is achieved.

  Furthermore, compared to the case where the tip holder is not provided with ribs and is simply made thin, the ink container is bent inward even when it is strongly press-fitted when press-fitting the ink-containing cylinder in order to suppress a decrease in rigidity. As a result, the ease of assembly is enhanced, the press-fitting force is less likely to decrease with time and impact, and ink leakage is less likely to occur from the fitting portion between the chip holder and the ink container.

  According to the configuration of claim 2 of the present invention, since the inscribed circle diameter of the rib increases toward the rear, the main stream flowing from the ink containing cylinder into the inscribed circle of the rib flows smoothly. be able to.

  According to the configuration of claim 3 of the present invention, the rear hole is composed of a front hole part and a rear hole part having a larger inner diameter than the front hole part connected to the rear of the front hole part, By forming the ribs in the front hole portion and the rear hole portion, the ink for the ballpoint pen can smoothly flow from the ink containing cylinder having a large inner diameter through the rear hole portion and the front hole portion into the ball pen tip having a small inner diameter. it can.

  The object of the present invention is to provide a ballpoint pen refill that has good ink followability, is easy to press-fit and fit between the tip holder and the ink containing cylinder, and hardly causes ink leakage from the fitting portion between the tip holder and the ink containing cylinder. Could be provided with a simple structure.

It is a longitudinal cross-sectional view of the ball-point pen refill of Example 1. FIG. 2 is an enlarged view of a main part, partly omitted in FIG. 1. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG.

  Next, examples of the multi-core writing instrument of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

Example 1
The ballpoint pen refill 1 according to the first embodiment shown in FIGS. 1 to 4 is mounted by press-fitting a press-fitting mounting portion 3e formed at the rear end portion of the chip holder 3 into the tip portion of the ink containing cylinder 2. A ball-point pen refill 1 is obtained by press-fitting and mounting a ball-point pen tip 4 holding a ball 5 in a rotatable manner. A coil spring 9 that presses the ball 5 against the inner wall of the tip end of the tip is disposed in the ballpoint pen tip 4, and a tail plug 6 is attached to the rear end of the ink containing cylinder 2.

  The chip holder 3 will be described in detail. Inside the chip holder 3, a fitting hole 3a for attaching the ball-point pen tip 4 to the tip portion, and a communication hole 3b having a smaller diameter than the fitting hole 3a are provided behind the fitting hole 3a. A rear hole 3c having a diameter larger than that of the communication hole 3b is formed at the rear of the communication hole 3b and at least in a position corresponding to the press-fit mounting portion 3e. Further, six ribs 3d are formed in the rear hole 3c at different positions in the circumferential direction.

  More specifically, the rear hole 3c formed in the rear end portion of the chip holder 3 is provided with a front hole portion 3ca having a diameter of 3.0 mm and a rear hole portion 4cb having a diameter of 4.0 mm behind the front hole portion 3ca. There is a rib 3da that protrudes toward the axial center in the front hole portion 3ca and extends along the longitudinal direction, and a rib 3db that protrudes toward the axial center in the rear hole portion 3cb and extends in the longitudinal direction. Six are formed at different positions in the circumferential direction.

  The thickness L of the rib 3d is gradually increased from 0.5 mm toward the outside on the axial center side, and is provided at six positions at different circumferential positions and at equal intervals of about 60 degrees. The inscribed circle diameter of the rib 3d is such that the inscribed circle diameter R1 on the front end side of the front hole portion 3ca is 1.8 mm, the inscribed circle diameter R2 on the rear end side of the rear hole portion 3cb is 2.0 mm, The inscribed circle diameter of 3d is provided to expand toward the rear. The inner diameter r1 of the front hole 3ca is smaller than the inner diameter r2 of the rear hole 3cb. Further, the thicknesses G1 and G2 of the chip holder 3 in the portion where the rib 3 is not formed in the front hole portion 3ca and the rear hole portion 3cb are substantially equal.

  When the ballpoint pen ink 7 is consumed by writing, it flows from the ink containing cylinder 2 into the ballpoint pen tip 4 through the rear hole 3c of the chip holder 3 and further through the communication hole 3b. At this time, the ballpoint pen ink 7 flowing in the rear hole 3c flows into the ballpoint pen tip 4 from the rear hole 3d through the communication hole 3b. Further, in the rear hole 3c, a main flow that flows in the inscribed circle of the rib 3 on the axial center side and a secondary flow that flows between the ribs 3 flow toward the communication hole 3b.

  Further, the front end surface 3f of the front hole 3ca and the front end surface 3g of the rear hole 3cb are surfaces whose inner diameters become smaller toward the front end. In this way, the front end surface 3f of the front hole portion 3ca and the front end surface 3g of the rear hole portion 3cb are surfaces having an inner diameter that decreases toward the front end, so that the front hole portion 3ca and the front hole portion are formed from the rear hole portion 3cb. This is preferable because the ink can smoothly flow from the portion 3ca to the communication hole 3b.

In the ink container 2, a water-based gel ink ballpoint pen ink 7 having a shear rate of 1.92 sec ^{−1 and} an ink viscosity of 1800 mPa · s and a grease-like ink follower 8 are directly stored at the rear end of the ink. It is. The ink consumption per 100 m of the writing distance was 170 mg. The ink viscosity was measured in a 20 ° C. environment using a Brookfield DV-II viscometer (CPE-42 rotor) manufactured by Brookfield, and the ink consumption was JIS P3201 writing paper as writing paper. On A, the writing angle was 65 ° and the writing load was 100 g, and the writing speed was 4 m / min.

  In the present embodiment, six ribs 3d are formed for the sake of convenience, but the thickness, the number, etc. are not particularly limited. The rib provided in the rear hole 3d may be provided in the entire length in the longitudinal direction of the rear hole 3d, but the rear end of the rib 3d is positioned forward of the rear end of the chip holder 3 in the longitudinal direction. By forming a substantially cylindrical introduction hole 3h behind the rib 3d, the ink flows from the ink containing cylinder 2 having a large inner diameter into the introduction hole 3h and from the introduction hole 3h to the rear hole 3d. Since the possible change in the cross-sectional area is small, the ballpoint pen ink 7 can flow smoothly.

  Further, the length and interval of each rib are not particularly limited, but considering the action of capillary action, the circumferential gap between the ribs is preferably 0.1 to 1.0 mm, preferably 0.5 mm. The following is more preferable, and it is most preferable to provide them uniformly in the circumferential direction. The individual ribs may also be provided with a uniform width toward the shaft center, but it is preferable to reduce the width toward the shaft center because the strength of the press-fit portion can be further increased.

  The ballpoint pen refill of the present invention can be used without being limited to the ink used, and can be used regardless of the type of ink such as oil-based ballpoint pen ink, water-based ballpoint pen ink, and correction ink. As widely available.

  Ink viscosity and ink consumption are not particularly limited, but since there is a tendency that a higher ink consumption tends to be preferable, an ink consumption of 100 mg or more per 100 m of writing distance is preferable, and more preferably 200 mg or more. It is preferable to use a ballpoint pen refill.

DESCRIPTION OF SYMBOLS 1 Ball-point pen refill 2 Ink receiving cylinder 3 Tip holder 3a Insertion hole 3b Communication hole 3c Rear hole 3ca Front hole part 3cb Back hole part 3d Rib 3e Press-fit mounting part 3f, 3g Front end surface 3h Introduction hole 4 Ball-point pen tip 5 Ball 6 Tail plug 7 Ballpoint pen ink 8 Ink follower

Claims (3)

In a ballpoint pen refill in which a tip holder is press-fitted and attached to the tip of the ink containing cylinder, and a tip of the tip holder is mounted with a ballpoint pen tip that rotatably holds a ball, the ink is attached to the rear end of the tip holder. A rear hole communicating with the housing cylinder is provided, and a plurality of ribs extending in the longitudinal direction and extending in the longitudinal direction are formed on the inner wall of the rear hole at different positions in the circumferential direction. The circumferential gap between adjacent ribs provided in the width decreases toward the axial center, and the circumferential gap between adjacent ribs is 0.1 to 1.0 mm. Ballpoint pen refill. 2. The ballpoint pen refill according to claim 1, wherein an inscribed circle diameter of the rib increases toward a rear side. The rear hole is composed of a front hole and a rear hole having a larger inner diameter than the front hole, which is connected to the rear of the front hole, and the rib is formed in the front hole and the rear hole. And the thickness of the tip holder of the part which does not form the said rib in the said front hole part and a back hole part is substantially equivalent, The ball-point refill of Claim 1 or 2 characterized by the above-mentioned.

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