JP3139148U - Ballpoint pen tip - Google Patents

Abstract

The present invention provides a ballpoint pen tip that can prevent a ball from falling off for a long period of time despite having a minimal ball and has sufficient writing performance with no handwriting interruption.
A ball receiving seat 3 is formed on the inner surface near the tip of a metal cylinder 2. A ball 5 having an outer diameter of less than 0.3 mm is accommodated on the front side of the ball receiving seat 3. The caulking portion 4 is formed by deforming the tapered tip portion 21 of the metal cylinder 2 inwardly in a circumferential shape. A ball 5 is rotatably held between the ball seat 3 and the caulking portion 4. A part of the ball 5 is projected forward from the tip of the crimping portion 4. When the outer diameter of the ball 5 is A, the inner diameter of the crimping portion 4 is H, and the protruding dimension from the tip of the crimping portion 4 of the ball 5 is L, “0.010 mm <A−H <0.035 mm” and “0 .. 15 <L / A <0.30 ”is satisfied.
[Selection] Figure 1

Description

The present invention relates to a ballpoint pen tip having a very small ball (that is, a ball having an outer diameter of less than 0.3 mm).

Conventionally, in this type of ball-point pen tip, in Claim 3 of Patent Document 1, in the vicinity of one end of the metal thin tube, a plurality of locations equidistant from the one end are pressed and deformed inward to form inward projections. A ball-point pen tip comprising a holder and a ball having a diameter of less than 0.3 mm inserted between the inward projection and the one end, and having a crimped portion formed by caulking the edge of the one end inward. When the diameter of the ball is D, the diameter of the inscribed circle of the inward projection is F, the projected dimension of the ball from the tip of the caulking portion is G, and the inner diameter of the caulking portion is H,
0.4 ≦ F / D ≦ 0.6, G / D ≧ 0.25
And 0.005 mm ≦ DH−0.010 mm
The ball-point pen tip characterized by satisfying the following relationship is disclosed.

JP 2003-251979 A

In general, in the case of a ballpoint pen tip having a very small ball (that is, a ball having an outer diameter of less than 0.3 mm), as shown in FIG. The part is buried in the paper. In particular, when the writing pressure is high, the amount of the ball and the caulking portion embedded in the paper surface is significant. For this reason, the ball-point pen tip having a tiny ball is gradually worn when the crimped portion comes into contact with the paper surface during writing, and the ball may drop out to the outside in a short period of time.

The ballpoint pen tip of Patent Document 1 places importance on eliminating the feeling of catching at the time of writing, restrains the amount of deformation of the caulking portion to be relatively small, and makes the ratio of the ball protruding dimension with respect to the ball outer diameter a general ball ( For example, it is configured to be set relatively large like a ball having an outer diameter of 0.5 mm. As a result, it is difficult for the ballpoint pen tip of Patent Document 1 to prevent the ball from falling off for a long period of time.

Further, since the ball pen tip of Patent Document 1 has a relatively small inward protrusion amount of the ball receiving seat, it is difficult to sufficiently prevent wear of the ball receiving seat. Therefore, the ball seat is greatly worn by writing, and the gap between the crimped portion and the ball becomes large. As a result, when writing, the inner peripheral edge of the caulking portion scratches the paper surface, and not only a good writing feeling is obtained, but also a problem that foreign matter such as fiber scraps on the paper surface is mixed in the ball holding portion (ie, paper jam). As a result, ink outflow and smooth rotation of the ball were hindered, and there was a risk that handwriting was interrupted, or writing could not be performed with the filled ink remaining in the ballpoint pen body.

The present invention solves the above-mentioned problems, and provides a ballpoint pen tip that has sufficient writing performance that can prevent the ball from falling off for a long period of time despite having a tiny ball. To provide a ballpoint pen tip that has sufficient writing performance with no traces of handwriting despite having a tiny ball, and to provide a ballpoint tip that can prevent the ball from falling off for a long time despite having a tiny ball The purpose is to do.

In order to solve the above problems, the present inventors have the following a. b. Focused on this point.
a. The tip of a ballpoint pen tip with a very small ball (especially a needle-type ballpoint pen tip with a very small ball) is sharp, and as shown in FIG. The tapered tip end is always deeply buried in the paper surface, and the paper surface is temporarily recessed. For this reason, even if the ball protruding dimension is set to be small to some extent, the temporarily recessed paper surface and the ball are sufficiently in contact with each other, and sufficient writing performance without handwriting interruption is obtained.
b. In the case of a ballpoint pen with a very small ball, writing to details (for example, partial writing to a notebook or printed document) is the main usage, so a ball with a general outer diameter (for example, outer diameter 0.5 mm) Smooth writing feeling like a ballpoint pen equipped with a ball) is not required.
The present inventors paid attention to the above points, and as a result of intensive research, they came to complete the present invention.

[1] The first device of the present application is to form a ball receiving seat 3 on the inner surface in the vicinity of the tip of the metal cylinder 2, and accommodate a ball 5 having an outer diameter of less than 0.3 mm on the front side of the ball receiving seat 3; A caulking portion 4 is formed by inwardly deforming the tapered tip portion 21 of the metal cylinder 2 in a circumferential shape, and the ball 5 is rotatably held between the ball receiving seat 3 and the caulking portion 4. A ball-point pen tip 1 having a part of a ball 5 protruding forward from the tip of the crimping portion 4;
When the outer diameter of the ball 5 is A, the inner diameter of the crimping portion 4 is H, and the protruding dimension from the tip of the crimping portion 4 of the ball 5 is L,
0.010mm <A-H <0.035mm
And 0.15 <L / A <0.30
(1) is satisfied.

In the ballpoint pen tip 1 of the first aspect, when the outer diameter A of the ball 5 is less than 0.3 mm (millimeter), the difference A−H between the outer diameter A of the ball and the inner diameter H of the caulking portion 4 is set to 0. By making it larger than 010 mm (millimeter) (that is, 0.010 mm <AH), the ball is prevented from falling off over a long period of time. This is because if the difference AH between the ball outer diameter A and the inner diameter H of the caulking portion 4 is 0.010 mm or less (that is, AH ≦ 0.010 mm), the amount of crimp deformation is reduced. This is because the ball may drop out in a short period of time from the start of use depending on the conditions used for writing.

Further, in the ballpoint pen tip 1 of the first aspect, when the outer diameter A of the ball 5 is less than 0.3 mm, the value of the ratio L / A of the ball protruding dimension L to the ball outer diameter A is set to be larger than 0.15. (I.e., 0.15 <L / A), during writing, the contact state between the ball 5 and the paper surface 9 is maintained with normal writing pressure, and proper rotation of the ball 5 is maintained. There is no risk. Because, when the ratio L / A ratio of the ball protruding dimension L to the ball outer diameter A is 0.15 or less (that is, L / A ≦ 0.15), the writing is performed while being inclined with respect to the paper surface 9 In addition, the ball 5 may move away from the paper surface 9 and cause handwriting breaks.

Further, in the ballpoint pen tip 1 of the first aspect, the value of the difference AH between the ball outer diameter A and the inner diameter H of the crimping portion 4 is made smaller than 0.035 mm (millimeter) (that is, AH <0. 035 mm), the relationship of “0.15 <L / A” can be easily satisfied, which is advantageous in avoiding handwriting interruption. This is because if the value of AH is 0.035 mm or more, the amount of caulking deformation inward of the caulking portion becomes large, and it becomes difficult to obtain a sufficient ball protruding dimension L.

In the ballpoint pen according to the first aspect, the ratio L / A of the ball protruding dimension L to the ball outer diameter A is set to be smaller than 0.30 (that is, L / A <0.30). A gap between the ball 4 and the ball 5 can be secured, and sufficient ink outflow can be obtained during writing. Because, if the value of the ratio L / A of the ball protruding dimension L to the ball outer diameter A is 0.30 or more (that is, 0.30 ≦ L / A), a sufficient amount of caulking deformation that can prevent the ball from falling off When the relationship of “0.010 mm ≦ A−H” is satisfied, the gap between the caulking portion 4 and the ball 5 tends to be small, and as a result, the ink outflow is insufficient during writing. This is because the handwriting may be interrupted.

[2] In the ballpoint pen tip 1 of claim 1,
0.010mm <A-H <0.030mm
And 0.15 <L / A <0.25
(Claim 2) is preferable.

In the ballpoint pen tip 1 of the second aspect, the difference AH between the outer diameter A of the ball and the inner diameter H of the caulking portion 4 is made smaller than 0.030 mm (that is, AH <0.030 mm). Furthermore, the relationship of “0.15 <L / A” can be easily satisfied, which is advantageous in avoiding handwriting interruption. Further, since the ratio L / A of the ball protruding dimension L to the ball outer diameter A is set to be smaller than 0.25 (that is, L / A <0.25), the caulking for properly holding the ball is achieved. This makes it easy to set the amount of deformation of the caulking portion, further ensuring a clearance between the caulking portion 4 and the ball 5, and providing sufficient ink outflow properties during writing.

[3] The second device of the present application is to form a ball receiving seat 3 on the inner surface near the tip of the metal cylinder 2, and accommodate a ball 5 having an outer diameter of less than 0.3 mm on the front side of the ball receiving seat 3. A caulking portion 4 is formed by inwardly deforming the tapered tip portion 21 of the metal cylinder 2 in a circumferential shape, and the ball 5 is rotatably held between the ball receiving seat 3 and the caulking portion 4. A ball-point pen tip 1 having a part of a ball 5 protruding forward from the tip of the crimping portion 4;
When the outer diameter of the ball 5 is A, and the protruding dimension from the tip of the caulking portion 4 of the ball 5 is L,
0.15 <L / A <0.25
(3) is satisfied.

In the ballpoint pen tip 1 of claim 3, when the outer diameter A of the ball 5 is less than 0.3 mm, the value of the ratio L / A of the ball protruding dimension L to the ball outer diameter A is set to be larger than 0.15. (I.e., 0.15 <L / A), during writing, the contact state between the ball 5 and the paper surface 9 is maintained with normal writing pressure, and the proper rotation of the ball 5 is maintained, whereby the handwriting is interrupted. There is no risk of occurrence. Because, when the ratio L / A ratio of the ball protruding dimension L to the ball outer diameter A is 0.15 or less (that is, L / A ≦ 0.15), the writing is performed while being inclined with respect to the paper surface 9 In addition, the ball 5 may move away from the paper surface 9 and cause handwriting breaks.

Further, in the ballpoint pen tip 1 of claim 3, when the outer diameter A of the ball 5 is less than 0.3 mm, the value of the ratio L / A of the ball protruding dimension L to the ball outer diameter A is set smaller than 0.25. (I.e., L / A <0.25) makes it easy to set the amount of deformation of the crimping portion for properly holding the ball, and further secures the clearance between the crimping portion 4 and the ball 5. And sufficient ink spillability can be obtained during writing.

[4] In the third device of the present application, a ball receiving seat 3 is formed on the inner surface near the tip of the metal cylinder 2, and a ball 5 having an outer diameter of less than 0.3 mm is accommodated on the front side of the ball receiving seat 3. A caulking portion 4 is formed by inwardly deforming the tapered tip portion 21 of the metal cylinder 2 in a circumferential shape, and the ball 5 is rotatably held between the ball receiving seat 3 and the caulking portion 4. A ball-point pen tip 1 having a part of a ball 5 protruding forward from the tip of the crimping portion 4;
When the outer diameter of the ball 5 is A and the inner diameter of the caulking portion 4 is H,
0.010mm <A-H <0.035mm
(4) is satisfied.

When the outer diameter A of the ball 5 is less than 0.3 mm, the ballpoint pen tip 1 according to the fourth aspect has a difference AH between the ball outer diameter A and the inner diameter H of the crimping portion 4 larger than 0.010 mm. As a result (that is, 0.010 mm <AH), the ball is prevented from falling off over a long period of time. Because, if the difference AH between the outer diameter A of the ball and the inner diameter H of the crimping portion 4 is 0.010 mm or less (that is, AH ≦ 0.010 mm), the crimp deformation amount of the crimping portion This is because there is a possibility that the ball may drop out in a short period of time from the start of use depending on the writing and use conditions.

Further, in the ballpoint pen tip 1 of the fourth aspect, when the outer diameter A of the ball 5 is less than 0.3 mm, the difference A−H between the outer diameter A of the ball and the inner diameter H of the crimping portion 4 is 0.035 mm. By making it small (that is, AH <0.035 mm), it is easy to set the ball protruding dimension L so that there is no break in the handwriting even when writing with tilting with respect to the paper surface 9. If the value of AH is 0.035 mm or more (that is, 0.035 mm ≦ AH), the amount of crimp deformation at the crimping portion increases, the degree of freedom in setting the ball projection dimension L decreases, and the paper surface 9 However, it is difficult to set the ball protruding dimension L so that the handwriting is not interrupted even when writing at an angle with respect to. The AH value is smaller than 0.030 mm (that is, AH <0.030 mm), and the ball protruding dimension is such that there is no break in the handwriting even when writing with an inclination with respect to the paper surface 9. It is preferable in that it is easy to set L.

[5] In the ball-point pen tip 1 according to the first to fourth aspects, when the diameter of a virtual inscribed circle drawn at the center of the ball receiving seat 3 is B,
B / A <0.4
(5) is satisfied.

The ratio B / A of the diameter B of the virtual inscribed circle drawn at the center of the ball seat 3 (hereinafter referred to as the inner diameter B of the ball seat) to the outer diameter A of the ball was set to be smaller than 0.4. (That is, B / A <0.4) can sufficiently suppress wear of the ball seat. Thereby, writing defects (handwriting breakage and writing inability) caused by paper jams are avoided, and smooth ink outflow and good writing feeling can be obtained over a long period of time. The value of B / A is preferably larger than 0.25 (that is, 0.25 <B / A). If the value of B / A is 0.25 or less, the inner diameter B of the ball receiving seat 3 becomes extremely small, so that the formation of the ball receiving seat 3 becomes difficult in manufacturing. The value of B / A is more preferably greater than 0.3 (that is, 0.3 <B / A).

[6] In the ballpoint pen tip 1 of the first to fifth aspects, a straight cylindrical portion 22 is provided behind the tapered tip portion 21 of the metal cylinder 2, and the outer diameter D of the straight cylindrical portion 22 is 0.5 mm. Is preferable (D <0.5 mm) (Claim 6).

When the outer diameter D of the right cylindrical portion 22 is less than 0.5 mm (millimeters), as shown in FIG. 5, the tip of the ball-point pen tip 1 is sharpened like a needle, and the caulking portion 4 is further sharpened during writing. The ball is likely to be buried in the paper surface 9, and the ball may drop off in a short period of time from the start of use due to wear of the caulking portion 4 due to contact with the paper surface 9. However, in the ballpoint pen tip 1 according to the sixth aspect, the configuration according to the first to fifth aspects can work effectively and can sufficiently prevent the ball from falling off over a long period of time. That is, according to the sixth aspect of the present invention, the ball-point pen tip 1 provided with a needle-type minimal ball that can prevent the ball from dropping off over a long period of time is obtained. The straight cylindrical portion 22 is connected to the rear of the rear end of the tapered tip portion 21 and is formed at least from the rear end of the tapered tip portion 21 to the vicinity of the ball seat 3. Of course, the right cylindrical portion 22 may be formed from the rear end of the tapered tip portion 21 to the rear end of the metal cylinder 2. The right cylindrical portion 22 provides a ball-point pen tip having a needle shape.

[7] In the ballpoint pen tip 1 of claim 6, the outer diameter A of the ball 5 is 0.15 mm to 0.29 mm, and the outer diameter D of the right cylindrical portion 22 is 0.30 mm to 0.49 mm. (Claim 7) is preferable.

[8] In the ballpoint pen tip 1 of claim 7, the outer diameter A of the ball 5 is 0.25 mm to 0.28 mm, and the outer diameter D of the right cylindrical portion 22 is 0.40 mm to 0.48 mm. (Claim 8) is preferable.

[9] In the ballpoint pen tip 1 according to the first to eighth aspects, the ball receiving seat 3 is formed on the inner surface near the tip of the metal cylinder 2 by pressing and deforming the side wall near the tip of the metal cylinder 2 inward. (Claim 9) is preferable. Thereby, a needle-type ballpoint pen tip having a tiny ball can be easily obtained.

[10] In the ballpoint pen tip 1 of claims 1 to 8, the ball receiving seat 3 is formed on the inner surface in the vicinity of the tip of the metal cylinder 2 by cutting the inner surface in the vicinity of the tip of the metal cylinder 2. Claim 10) is preferred. Thereby, a cutting-type ball-point pen tip having a tiny ball can be easily obtained.

In the present invention, the outer diameter A of the ball 5 is the diameter of the ball 5. In the present invention, the ball protruding dimension L is a length in which the ball 5 protrudes forward in the axial direction from the tip of the crimping portion 4 when the ball 5 is in contact with the ball receiving seat 3. In the present invention, the inner diameter H of the caulking portion 4 is an inner diameter of a portion that protrudes most circumferentially inward in the radial direction of the inner surface of the caulking portion 4.

According to the first aspect of the present invention, it is possible to obtain a ball-point pen tip that can prevent the ball from falling off for a long period of time and has sufficient writing performance with no handwriting breakage despite the provision of the minimum ball.

According to the second aspect of the present invention, it is possible to obtain a ball-point pen tip that can prevent the ball from falling off for a long period of time and has a sufficient writing performance with no handwriting interruption even though the ball is provided.

According to the third aspect of the present invention, a ball-point pen tip having sufficient writing performance with no handwriting breakage can be obtained in spite of having the minimum ball.

According to the fourth aspect of the present invention, a ball-point pen tip that can prevent the ball from falling off for a long period of time despite the provision of the minimal ball is obtained.

According to the fifth aspect, wear of the ball seat can be sufficiently suppressed, writing failure caused by paper jam is avoided, and smooth ink outflow and good writing feeling can be obtained for a long time.

According to the sixth aspect, a needle type ballpoint pen tip having the effects of the first to fifth aspects can be obtained.

According to the seventh aspect, a needle-type ballpoint pen tip having the effects of the first to fifth aspects can be reliably obtained.

According to the eighth aspect, a needle-type ballpoint pen tip having the effects of the first to fifth aspects can be obtained more reliably.

According to the ninth aspect, a needle-type ballpoint pen tip having a tiny ball can be easily obtained.

According to the tenth aspect, it is possible to easily obtain a cutting type ball-point pen tip having a tiny ball.

The best mode for carrying out the present invention will be described.

A ball-point pen tip 1 according to an embodiment of the present invention includes a metal cylinder 2, a ball receiving seat 3 formed on the inner surface in the vicinity of the tip of the metal cylinder 2, and the tip of the tapered tip portion 21 of the metal cylinder 2. Are formed by deforming inwardly in a circumferential shape, and a ball 5 that is rotatably held between the ball receiving seat 3 and the crimping portion 4.

The said metal cylinder 2 consists of a cylindrical body of stainless steel (For example, austenitic stainless steel, such as SUS304, SUS305, SUS321).

The ball seat 3 is formed by, for example, pressing and deforming (punching) a side wall near the tip of the metal cylinder 2, cutting an inner surface near the tip of the metal cylinder 2, or pressing and deforming. And a combination of the above cutting processes.

The ball 5 is inserted into the front side of the ball receiving seat 3, and then the crimping portion 4 is formed by pressing and deforming (caulking) the tip of the tapered tip portion 21 of the metal cylinder 2 inward in a circumferential direction. It is formed. Thereby, the ball 5 is rotatably held between the crimping portion 4 and the ball seat 3. An inner diameter H of the caulking portion 4 is set smaller than the ball outer diameter A.

The ball 5 is a very small ball having an outer diameter A of less than 0.3 mm. In the present invention, the outer diameter A of the ball 5 may be less than 0.3 mm, preferably in the range of 0.15 mm to 0.29 mm, more preferably in the range of 0.20 mm to 0.29 mm. More preferably, a range of 0.25 mm to 0.28 mm is effective.

The difference A−H between the inner diameter H of the crimping portion 4 and the outer diameter A of the ball is set to a value larger than 0.010 mm and smaller than 0.035 mm (that is, 0.010 mm <A−H < 0.035 mm). Preferably, the value of AH is set to a value larger than 0.010 mm and smaller than 0.030 mm (that is, 0.010 mm <AH <0.030 mm).

The value of the ratio L / A of the ball protruding dimension L to the ball outer diameter A is set to a value larger than 0.15 and smaller than 0.30 (that is, 0.15 <L / A <0.30). ). Preferably, the value of L / A is set to a value larger than 0.15 and smaller than 0.25 (that is, 0.15 <L / A <0.25).

The ratio B / A of the inner diameter B of the ball receiving seat 3 to the outer diameter A of the ball is set to be larger than 0.25 and smaller than 0.4 (that is, 0.25 <B / A < 0.4). Preferably, the value of B / A is set larger than 0.3 and smaller than 0.4 (that is, 0.3 <B / A <0.4).

The ball-point pen tip 1 is preferably a needle type in which a straight cylindrical portion 22 is continuously provided behind the tapered tip portion 21 of the metal cylinder 2. In the present invention, the outer cylindrical portion 22 has an outer diameter D of less than 0.5 mm, specifically, the outer cylindrical portion 22 has an outer diameter D in the range of 0.30 mm to 0.49 mm, preferably The outer diameter D of the right cylindrical portion 22 is in the range of 0.40 mm to 0.48 mm, more preferably, the outer diameter D of the right cylindrical portion 22 is in the range of 0.45 mm to 0.48 mm. It is effective to be.

Embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 shows a ballpoint pen tip 1 according to a first embodiment of the present invention. The ball-point pen tip 1 of the present embodiment has a straight cylindrical metal tube 2 made of SUS321, and a plurality of (here, punched) inner surfaces formed near the tip of the metal tube 2 by punching. 3) ball receiving seats 3 formed by inward projections, a crimping portion 4 formed by inwardly deforming the tip of the tapered tip portion 21 of the metal cylinder 2 in a circumferential direction, and the ball receiving seat And a ball 5 that is rotatably held between the crimping portion 4 and the crimping portion 4.

Two types of balls 5 having an outer diameter A of 0.25 mm and 0.28 mm are employed. The metal cylinder 2 is formed with a straight cylindrical portion 22 having a substantially constant outer diameter from the rear end of the tapered tip portion 21 positioned in front of the ball receiving seat 3 to the rear end of the metal cylinder 2. Become. When the outer diameter A of the ball 5 is 0.25 mm, the outer diameter D of the right cylindrical portion 22 is set to 0.45 mm, and when the outer diameter A of the ball 5 is 0.28 mm, the right cylindrical shape. The outer diameter D of the portion 22 is set to 0.48 mm.

FIG. 2 shows an example of a ballpoint pen 6 to which the ballpoint pen tip 1 of the embodiment of FIG. 1 is applied. The ballpoint pen 6 comprises a shaft cylinder 7 and a ballpoint pen refill 8 accommodated in the shaft cylinder 7.

(Shaft tube)
The shaft cylinder 7 includes a metal front shaft 71, a synthetic resin rear shaft 72, and a synthetic resin tail plug 73.

(Front axis)
The front shaft 71 is obtained by cutting a metal material (for example, brass). An outer peripheral surface of the tip portion of the tip shaft 71 is formed into a tapered shape by cutting. In addition, a straight tip hole is penetrated by cutting at the tip of the tip shaft 71, and a tapered inner surface is formed by cutting on the inner surface of the tip shaft 71 behind the tip hole. Further, an internal thread portion is formed on the inner surface of the front shaft 71 behind the tapered inner surface by cutting.

(Rear axis)
The rear shaft 72 is obtained by injection molding of synthetic resin. A male screw portion is formed on the outer peripheral surface of the front end portion of the rear shaft 72, and the male screw portion and the female screw portion of the front shaft 71 are detachably screwed together. A tail plug 73 is press-fitted and fixed to the rear end opening of the rear shaft 72.

(Ball pen refill)
The ballpoint pen refill 8 includes the ballpoint pen tip 1 of FIG. 1, a synthetic resin holder 82 to which the ballpoint pen tip 1 is fixed at the front end portion, and an outer peripheral surface of the ballpoint pen tip 1 that is fixed to the front end portion of the holder 82. A support cylinder 83 for supporting the ink and an ink containing tube 81 having the holder 82 fixed to the front end opening and the rear end opened.

(Ink tube)
The ink containing tube 81 is obtained by extrusion molding of a synthetic resin (for example, polypropylene). An ink 81a (for example, a water-based gel ink) and a follower 81b (for example, a high-viscosity fluid) that is disposed at the rear end of the ink 81a and moves forward as the ink 81a is consumed are disposed inside the ink storage tube 81. Filled.

(holder)
The holder 82 is obtained by injection molding of a synthetic resin (for example, polypropylene). The holder 82 is formed by integrally forming a cylindrical front portion, a flange portion provided continuously behind the cylindrical front portion, and a cylindrical rear portion provided continuously behind the flange portion. A ballpoint pen tip 1 is press-fitted and fixed to the cylindrical front portion. The collar portion is brought into contact with the front end surface of the ink containing tube 81, the front end surface of the rear shaft 72, and the tapered inner surface of the front shaft 71. The cylindrical rear portion is press-fitted and fixed to the front end opening of the ink containing tube 81.

(Support tube)
A metal support cylinder 83 is fixed to the outer peripheral surface of the cylindrical front portion of the holder 82. The support cylinder 83 supports the outer peripheral surface behind the tip of the ballpoint pen tip 1 to prevent the ballpoint pen tip 1 from wobbling during writing.

(Test results)
Tables 1 and 2 show the results of the ball drop test and the handwriting break test performed with the ballpoint pen 6 shown in FIG.

Table 1 shows that in the ballpoint pen tip 1 having the structure shown in FIG. 1 having a ball outer diameter A of 0.25 mm, five samples each having a different combination of AH value and L / A value are prepared. The result of having applied and tested to the ball-point pen 6 shown in FIG. 2 is shown. Table 2 shows five samples each having a different combination of A-H and L / A values in the ball-point pen tip 1 having the structure shown in FIG. 1 having a ball outer diameter A of 0.28 mm. The result of having applied and tested to the ball-point pen 6 shown in FIG. 2 is shown.

(Ball drop test)
In the ball drop test, the writing angle (that is, the angle formed between the paper surface 9 and the axis of the ball-point pen tip 1) is 50 degrees, the writing load is 150 g (grams), and the zipper runs at 4 m / min while being rotated by a running writing tester. I went. In addition, five writing papers were set on top of an underlay made of a hard vinyl chloride resin plate. Confirmation of ball drop-off was made by contacting the tip of the ball-point pen tip 1 with the adhesive surface of the adhesive tape at every writing distance of 200 m and examining whether or not the ball was dropped. The evaluation of the result of the ball drop test was evaluated as “◯” when no ball drop was observed by a writing distance of 1000 m, and “X” when ball drop was observed. In the handwriting break test, "-" is indicated for "x" because the ball drop test was not performed.

(Handwriting break test)
In the handwriting break test, the prepared ballpoint pen 6 was confirmed by handwriting by three inspectors. The evaluation of the result of the handwriting break test is `` ○ '' when the handwriting breakage does not occur, `` △ '' when the handwriting breakage does not occur unless the writing angle is extremely small, `` When the handwriting breakage frequently occurs '' × ”.

FIG. 3 is a graph showing the results of Table 1. L / A is taken on the vertical axis, AH is taken on the horizontal axis, and Examples 1 to 3 and Comparative Examples 1 to 1 in Table 1 are taken. The values of L / A and AH in Comparative Example 5 were plotted with black circles “●”. The numbers in parentheses below the plot “●” show the ball drop test result and the handwriting break test result corresponding to the plot, the left shows the ball drop test result, and the right shows the hand break test result. From the graph of FIG. 3, it can be seen that when the value of AH is larger than 0.010 mm (that is, 0.010 mm <AH), the ball does not drop out. In addition, it can be seen from the graph of FIG. 3 that when the value of L / A is larger than 0.15 (that is, when 0.15 <L / A), handwriting breaks hardly occur.

FIG. 4 is a graph showing the results of Table 2. L / A is taken on the vertical axis, AH is taken on the horizontal axis, and Examples 1 to 5 and Comparative Examples 1 to 1 in Table 2 are taken. The values of L / A and AH in Comparative Example 3 were plotted with black circles “●”. The numbers in parentheses below the plot “●” show the ball drop test result and the handwriting break test result corresponding to the plot, the left side shows the ball drop test result, and the right shows the hand break test result. It can be seen from the graph of FIG. 4 that when the value of AH is larger than 0.010 mm (that is, when 0.010 mm <AH), the ball does not drop out. Further, it can be seen from the graph of FIG. 4 that when the value of L / A is larger than 0.15 (that is, when 0.15 <L / A), handwriting breakage hardly occurs.

Tables 3 and 4 show the results of the writing test performed with the ballpoint pen 6 shown in FIG.

Table 3 shows that five samples each having a different B / A value are prepared in the ballpoint pen tip 1 having the structure shown in FIG. 1 having a ball outer diameter A of 0.25 mm, and these are applied to the ballpoint pen 6 shown in FIG. The test results are shown below.

Table 4 shows five samples each having a different B / A value in the ballpoint pen tip 1 having the structure shown in FIG. 1 having a ball outer diameter A of 0.28 mm, and applying them to the ballpoint pen 6 shown in FIG. The test results are shown below.

(Writing test)
In the writing test, a writing tester (writing angle) that writes in a spiral using the ballpoint pen 6 shown in FIG. 2 in which the ink 81a filled in the ink containing tube 81 is an aqueous gel ink with a filling amount of 0.4 g. 70 degrees, writing load 100 g, writing speed 4 m / min). The wear of the ball seats in Tables 3 and 4 was measured after 700 m was written with the writing tester. Incidentally, the wear values of the ball seats in Tables 3 and 4 are average values of 5 balls each. In addition, the writing failure in Tables 3 and 4 means that the filling ink cannot be consumed until the end, and the numerical values shown in Tables 3 and 4 indicate the number of occurrences of writing failure in each of the five. To express.

As shown in the results of Tables 3 and 4, those with large wear of the ball seats (Comparative Example 1 and Comparative Example 2 in Table 3 and Comparative Example 1 and Comparative Example 2 in Table 4) were written out due to a paper jam or the like. Defects occurred or handwriting was interrupted. On the other hand, in the case where the wear of the ball seat was small (Example 1 in Table 3 and Example 1 in Table 4), writing defects did not occur and the filling ink could be consumed to the end.

[Second Embodiment]
FIG. 6 shows a ballpoint pen tip 1 according to a second embodiment of the present invention. The ball-point pen tip 1 of the present embodiment includes a cylindrical metal tube 2 made of SUS304 having a tapered tip 21, and a ball receiving seat 3 formed by cutting on the inner surface near the tip of the metal tube 2. The caulking portion 4 formed by inwardly deforming the tip of the tapered tip portion 21 of the metal cylinder 2 in the circumferential direction, and the ball receiving seat 3 and the caulking portion 4 are rotatably held. The ball 5 is held.

The tapered tip portion 21 is formed on the outer surface of the tip portion of the metal cylinder 2 so as to extend rearward from the caulking portion 4 beyond the ball receiving seat 3. A central hole 31 and a plurality (three in this case) of ink guiding grooves 32 communicating radially with the central hole 31 are provided in the ball receiving seat 3 in the axial direction. Two types of balls 5 having an outer diameter A of 0.25 mm and 0.28 mm are employed.

FIG. 7 shows an example of a ballpoint pen 6 to which the ballpoint pen tip 1 of the embodiment of FIG. 6 is applied. The ballpoint pen 6 comprises a shaft cylinder 7 and a ballpoint pen refill 8 accommodated in the shaft cylinder 7.

(Shaft tube)
The shaft cylinder 7 includes a metal front shaft 71, a synthetic resin rear shaft 72, and a synthetic resin tail plug 73.

(Front axis)
The front shaft 71 is obtained by cutting a metal material (for example, brass). An outer peripheral surface of the tip portion of the tip shaft 71 is formed into a tapered shape by cutting. In addition, a straight tip hole is penetrated by cutting at the tip of the tip shaft 71, and a tapered inner surface is formed by cutting on the inner surface of the tip shaft 71 behind the tip hole. Further, an internal thread portion is formed on the inner surface of the front shaft 71 behind the tapered inner surface by cutting.

(Rear axis)
The rear shaft 72 is obtained by injection molding of synthetic resin. A male screw portion is formed on the outer peripheral surface of the front end portion of the rear shaft 72, and the male screw portion and the female screw portion of the front shaft 71 are detachably screwed together. A tail plug 73 is press-fitted and fixed to the rear end opening of the rear shaft 72.

(Ball pen refill)
The ball-point pen refill 8 includes the ball-point pen tip 1 shown in FIG. 6, a synthetic resin holder 82 to which the ball-point pen tip 1 is fixed at the front end portion, the holder 82 fixed to the front end opening portion, and the rear end being opened. And an ink containing tube 81.

(Ink tube)
The ink containing tube 81 is obtained by extrusion molding of a synthetic resin (for example, polypropylene). An ink 81a (for example, a water-based gel ink) and a follower 81b (for example, a high-viscosity fluid) that is disposed at the rear end of the ink 81a and moves forward as the ink 81a is consumed are disposed inside the ink storage tube 81. Filled.

(holder)
The holder 82 is obtained by injection molding of a synthetic resin (for example, polypropylene). The holder 82 is formed by integrally forming a cylindrical front portion, a flange portion provided continuously behind the cylindrical front portion, and a cylindrical rear portion provided continuously behind the flange portion. A ballpoint pen tip 1 is press-fitted and fixed to the cylindrical front portion. The collar portion is brought into contact with the front end surface of the ink containing tube 81, the front end surface of the rear shaft 72, and the tapered inner surface of the front shaft 71. The cylindrical rear portion is press-fitted and fixed to the front end opening of the ink containing tube 81.

(Test results)
Tables 5 and 6 show the results of the ball drop test and the handwriting break test performed with the ballpoint pen 6 shown in FIG.

Table 5 shows five samples each having a different combination of AH and L / A values in the ballpoint pen tip 1 having the structure shown in FIG. 6 having a ball outer diameter A of 0.25 mm. The result of having applied and tested to the ball-point pen 6 shown in FIG. 7 is shown. Table 6 shows that in the ballpoint pen tip 1 having the structure shown in FIG. 6 having a ball outer diameter A of 0.28 mm, five samples each having a different combination of AH value and L / A value are prepared. The result of having applied and tested to the ball-point pen 6 shown in FIG. 7 is shown.

(Ball drop test)
In the ball drop test, the writing angle (that is, the angle formed between the paper surface 9 and the axis of the ball-point pen tip 1) is 50 degrees, the writing load is 150 g (grams), and the zipper runs at 4 m / min while being rotated by a running writing tester. I went. In addition, five writing papers were set on top of an underlay made of a hard vinyl chloride resin plate. Confirmation of ball drop-off was made by contacting the tip of the ball-point pen tip 1 with the adhesive surface of the adhesive tape at every writing distance of 200 m and examining whether or not the ball was dropped. The evaluation of the result of the ball drop test was evaluated as “◯” when no ball drop was observed by a writing distance of 1000 m, and “X” when ball drop was observed. In the handwriting break test, "-" is indicated for "x" because the ball drop test was not performed.

(Handwriting break test)
In the handwriting break test, the prepared ballpoint pen 6 was confirmed by handwriting by three inspectors. The evaluation of the result of the handwriting break test is `` ○ '' when the handwriting breakage does not occur, `` △ '' when the handwriting breakage does not occur unless the writing angle is extremely small, `` When the handwriting breakage frequently occurs '' × ”.

FIG. 8 is a graph showing the results of Table 5, where L / A is taken on the vertical axis, AH is taken on the horizontal axis, and in Examples 1 to 5 and Comparative Example 1 in Table 5. The value of L / A and the value of AH were plotted by the black circle “●”. The numbers in parentheses below the plot “●” show the ball drop test result and the handwriting break test result corresponding to the plot, the left shows the ball drop test result, and the right shows the hand break test result. From the graph of FIG. 8, it can be seen that when the value of AH is larger than 0.010 mm (that is, when 0.010 mm <AH), the ball does not drop out. Further, it can be seen from the graph of FIG. 8 that when the value of L / A is larger than 0.15 (that is, when 0.15 <L / A), handwriting breaks hardly occur.

FIG. 9 is a graph showing the results of Table 6, with L / A on the vertical axis and AH on the horizontal axis, and Examples 1 to 3 and Comparative Examples 1 to 6 in Table 6. The values of L / A and AH in Comparative Example 3 were plotted with black circles “●”. The numbers in parentheses below the plot “●” show the ball drop test result and the handwriting break test result corresponding to the plot, the left side shows the ball drop test result, and the right shows the hand break test result. From the graph of FIG. 9, it can be seen that when the value of AH is larger than 0.010 mm (that is, when 0.010 mm <AH), the ball does not drop out. Further, it can be seen from the graph of FIG. 9 that when the value of L / A is larger than 0.15 (that is, when 0.15 <L / A), handwriting breaks hardly occur.

Tables 7 and 8 show the results of the writing test performed with the ballpoint pen 6 shown in FIG.

Table 7 shows that five samples each having a different B / A value are prepared in the ballpoint pen tip 1 having the structure shown in FIG. 6 having a ball outer diameter A of 0.25 mm, and these are applied to the ballpoint pen 6 shown in FIG. The test results are shown below.

Table 8 shows that five samples each having a different B / A value are prepared for the ballpoint pen tip 1 of the structure shown in FIG. 6 having a ball outer diameter A of 0.28 mm, and these are applied to the ballpoint pen 6 shown in FIG. The test results are shown below.

(Writing test)
The writing test is performed by using a ball pen 6 shown in FIG. 7 in which the ink 81a filled in the ink containing tube 81 is a water-based gel ink having a filling amount of 0.4 g (writing angle). 70 degrees, writing load 100 g, writing speed 4 m / min). The wear of the ball seats shown in Tables 7 and 8 was measured after 700 m was written using the writing tester. Note that the wear values of the ball seats in Tables 7 and 8 are average values of 5 balls each. In addition, the writing failure in Tables 7 and 8 means that the filling ink cannot be consumed to the end, and the numerical values shown in Tables 7 and 8 indicate the number of occurrences of the writing failure in each of the five. .

As shown in the results of Tables 7 and 8, those with large wear on the ball seats (Comparative Example 1 and Comparative Example 2 in Table 7 and Comparative Example 1 and Comparative Example 2 in Table 8) were cut off due to a paper jam or the like. A defect occurred. On the other hand, in the case where the wear of the ball seat was small (Example 1 in Table 7 and Example 1 in Table 8), no writing failure occurred and the ink could be consumed to the end.

(A) is a principal part expanded longitudinal sectional view which shows 1st Example of this invention ball-point pen tip, (b) is XX sectional drawing of the said (a). It is a longitudinal cross-sectional view which shows the example of application of the ball-point pen tip of FIG. It is a graph which shows the result of Table 1. It is a graph which shows the result of Table 2. It is an enlarged view which shows the contact state with the paper surface of this invention ball-point pen tip at the time of writing. (A) is a principal part expanded longitudinal sectional view which shows 2nd Example of this invention ball-point pen tip, (b) is the YY sectional view taken on the line (a). It is a longitudinal cross-sectional view which shows the application example of the ball-point pen tip of FIG. It is a graph which shows the result of Table 5. It is a graph which shows the result of Table 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Metal cylinder 21 Tapered tip part 22 Cylindrical part 3 Ball receiving seat 31 Center hole 32 Ink guide groove 4 Caulking part 5 Ball 6 Ball pen 7 Shaft cylinder 71 Lead shaft 72 Rear shaft 73 Tail plug 8 Ball-point pen refill 81 Ink receiving tube 81a Ink 81b Follower 82 Holder 83 Support cylinder 9 Paper surface A Outer diameter of ball B Inner diameter of ball receiving seat L Outer diameter of ball H Inner diameter of caulking portion D Outer diameter of right cylindrical portion

Claims (10)

A ball seat is formed on the inner surface in the vicinity of the tip of the metal cylinder, a ball having an outer diameter of less than 0.3 mm is accommodated on the front side of the ball seat, and the tapered tip of the metal cylinder is formed in a circumferential shape. A ballpoint pen that forms a crimped portion by deforming in the direction, holds the ball rotatably between the ball receiving seat and the crimped portion, and projects a part of the ball forward from the tip of the crimped portion A chip,
When the outer diameter of the ball is A, the inner diameter of the crimped portion is H, and the protruding dimension from the tip of the crimped portion of the ball is L,
0.010mm <A-H <0.035mm
And 0.15 <L / A <0.30
Ballpoint pen tip, characterized by satisfying the relationship. The outer diameter A of the ball, the inner diameter H of the caulking portion, and the protruding dimension L from the tip of the caulking portion of the ball are:
0.010mm <A-H <0.030mm
And 0.15 <L / A <0.25
The ball-point pen tip according to claim 1 satisfying the relationship: A ball seat is formed on the inner surface in the vicinity of the tip of the metal cylinder, a ball having an outer diameter of less than 0.3 mm is accommodated on the front side of the ball seat, and the tapered tip of the metal cylinder is formed in a circumferential shape. A ballpoint pen that forms a crimped portion by deforming in the direction, holds the ball rotatably between the ball receiving seat and the crimped portion, and projects a part of the ball forward from the tip of the crimped portion A chip,
When the outer diameter of the ball is A and the protruding dimension from the tip of the caulking portion of the ball is L,
0.15 <L / A <0.25
Ballpoint pen tip, characterized by satisfying the relationship. A ball seat is formed on the inner surface in the vicinity of the tip of the metal cylinder, a ball having an outer diameter of less than 0.3 mm is accommodated on the front side of the ball seat, and the tapered tip of the metal cylinder is formed in a circumferential shape. A ballpoint pen that forms a crimped portion by deforming in the direction, holds the ball rotatably between the ball receiving seat and the crimped portion, and projects a part of the ball forward from the tip of the crimped portion A chip,
When the outer diameter of the ball is A and the inner diameter of the caulking portion is H,
0.010mm <A-H <0.035mm
Ballpoint pen tip, characterized by satisfying the relationship. When the diameter of a virtual inscribed circle drawn at the center of the ball seat is B,
B / A <0.4
The ball-point pen tip of Claim 1, 2, 3 or 4 which satisfies the relationship of these.   The ballpoint pen tip according to claim 1, 2, 3, 4, or 5, wherein a straight cylindrical portion is provided behind the tapered tip portion of the metal cylinder, and an outer diameter D of the straight cylindrical portion is less than 0.5 mm.   The ballpoint pen tip according to claim 6, wherein an outer diameter A of the ball is 0.15 mm to 0.29 mm, and an outer diameter D of the right cylindrical portion is 0.30 mm to 0.49 mm.   The ballpoint pen tip according to claim 7, wherein an outer diameter A of the ball is 0.25 mm to 0.28 mm, and an outer diameter D of the right cylindrical portion is 0.40 mm to 0.48 mm.   The ball receiving seat is formed on the inner surface in the vicinity of the tip of the metal cylinder by pressing and deforming the side wall in the vicinity of the tip of the metal cylinder inward. Ballpoint pen tip as described.   9. The ballpoint pen according to claim 1, wherein a ball receiving seat is formed on the inner surface in the vicinity of the tip of the metal cylinder by cutting the inner surface in the vicinity of the tip of the metal cylinder. Chip.

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