JP7240803B2 - writing instrument - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) Meeting name: 2016 Product Study Group New Product Presentation (Osaka venue) Date: August 26, 2016 (2) Meeting name: 2016 Product Study Group New Product presentation (Tokyo venue) date: September 8-9, 2016 (3) Sale date: October 14, 2016

TECHNICAL FIELD The present invention relates to an improvement in a writing instrument that has an appropriate coefficient of friction on the surface of its barrel and is provided with a protective film with high hardness, thereby providing a high-class feeling and excellent durability.

2. Description of the Related Art In a ballpoint pen, a mechanical pencil, or a compound writing instrument having a plurality of writing bodies housed in a barrel, the surface of the barrel is decorated to give an aesthetic impression.
In this case, for writing instruments in a relatively low price range, there has been proposed one in which a barrel is directly subjected to a decoration treatment such as coating, transfer, printing, or plating (see Patent Document 1).
Also, a proposal has been made to laminate a transfer film on which an image is formed by color printing or the like on the surface of the barrel (see Patent Document 2).

However, in the writing instrument disclosed in Patent Document 1, there are problems such as poor wear resistance and corrosion resistance of the decorative portion, and the base of the barrel is exposed with the passage of time and becomes unsightly. ing.
In addition, in the writing instrument disclosed in Patent Document 2, since the film onto which the color printing is transferred is attached to the barrel, the film may come off during use, and the barrel is slippery and lacks a feeling of grip. etc.

Therefore, in order to ensure the durability of the surface of the barrel, there has been proposed a writing instrument having a barrel coated with a high-hardness protective film (metal coating) (see Patent Document 3).
According to the writing instrument disclosed in Patent Literature 3, the high-hardness metal coating provides a deep luster, which improves the quality of the appearance and contributes to giving the writing instrument a high-class feel.

WO2013/008811 JP 2010-253842 A Japanese Utility Model Laid-Open No. 60-173380

By the way, according to the writing instrument disclosed in Patent Document 3, although the high-hardness metal coating contributes to improving the durability of the barrel, the metal coating has a low coefficient of friction, which makes it slippery and hinders accurate writing. There are technical issues such as

Therefore, the present invention can improve the durability of the barrel by applying a film with high hardness to the barrel, and solves the problem of slipperiness by providing the film with an appropriate coefficient of friction. To provide a writing utensil excellent in high-class feeling, which is improved in appearance quality by being accompanied by luster.

A writing instrument according to the present invention, which has been made to solve the above-described problems, includes a barrel having a surface coated with a film , and a writing part housed in the barrel and protruding from the front end of the barrel. A writing instrument comprising a refill, wherein a film formed by ion plating TIN (titanium nitride) on the Cr plating applied to the barrel has a hardness of Hv 1800 or more, and the film is brought into contact with the paper surface. The friction coefficient is 0.25 or more when the load is 2.5 N and the sliding speed is 20 cm/sec, and the barrel is composed of a front shaft and a rear shaft, and a male screw and a female screw are provided between the two. and the tip of the front barrel is detachably connected to the distal end of the front barrel by a combination of a male screw and a female screw. The turning direction for releasing is set to the left, and the turning direction for releasing the coupling of the screw of the tip portion with respect to the front barrel is set to the right . Hv mentioned here is the Vickers hardness, which is measured by a commercially available micro Vickers measuring instrument (for example, a micro Vickers measuring instrument MVK-1C manufactured by Akashi (now Mitutoyo)).

In this case, the barrel is composed of a front barrel and a rear barrel whose outsides are made of different materials. In the a*b* color system, the range is selected so that the difference in L* value is 20 or less, the difference in a* value is 10 or less, and the difference in b* value is 10 or less.

Also, a configuration in which a nickel plating layer is formed on the material forming the shaft cylinder and a coating layer is further formed on the nickel plating layer can be preferably adopted.

According to the writing instrument according to the present invention, by setting the hardness of the film formed on the barrel and the friction coefficient of the film within the specific ranges described above, the durability of the film is excellent and the friction coefficient is appropriate. It is possible to provide a writing utensil with which a grip feeling can be obtained.
In a writing instrument having a barrel composed of a front barrel and a rear barrel, the color difference of the film formed on each of the front barrel and the rear barrel is within the above-mentioned range indicated by the L*a*b* color system. By setting, it is possible to provide a writing instrument with well-balanced brightness and color tone.
As a result, it is possible to provide a writing utensil that has a deep metallic luster and can meet the user's high-class taste.

It is (A) a front view, (B) a right side view, and (C) a rear view of a compound writing instrument according to an embodiment of the present invention. 2 is a central cross-sectional view of the compound writing instrument shown in FIG. 1; FIG. They are (A) a front view, (B) a right side view, and (C) a sectional view of a rear barrel used in the compound writing instrument shown in FIG. 1 . FIG. 4 is an enlarged cross-sectional view seen in the direction of the arrow from line IV-IV in FIG. 3(C); They are (A) a front view, (B) a right side view, (C) a rear view, and (D) a sectional view of an inner cylinder used in the compound writing instrument shown in FIG. It is (A) a front view of the front barrel used for the compound writing instrument shown in FIG. 1, and (B) sectional drawing. 1. It is the (A) front view of the base used for the compound writing instrument shown in FIG. 1, and (B) sectional drawing. They are (A) front view, (B) right side view, and (C) rear view of the knock stick used for the compound writing instrument shown in FIG. FIG. 8B is an enlarged cross-sectional view seen in the direction of the arrow from line IX-IX in FIG. 8B; FIG. 3 is an enlarged cross-sectional view seen in the direction of the arrow from the line XX in FIG. 2; 3 is an enlarged view of the crown portion of the compound writing instrument shown in FIG. 2; FIG. FIG. 3 is a cross-sectional view showing a state in which one writing part is protruded in the compound writing instrument shown in FIG. 2;

An example in which the present invention is applied to a compound writing instrument will be described with reference to the drawings.
(1) Appearance of Writing Instrument The writing instrument according to the embodiment is a compound writing instrument 10 having an appearance as shown in FIGS. 1(A) to 1(C). Note that FIG. 1 shows a non-writing state in which the tip writing portions of a plurality of refills housed inside the writing instrument 10 are all retracted.
The barrel 11 has a rear barrel 20 positioned on the rear end side and a front barrel 40 positioned on the front end side which are screwed together and connected. A ring member 12 is modified between the rear barrel 20 and the front barrel 40 . A base 50 as a nose portion is screwed and attached to the tip of the front barrel 40 .
The rear shaft 20 is made of a metal material, and has three longitudinal openings 22 at its rear portion. A knock projection 62 provided on the outer surface of a knock rod 60 attached to the rear of a refill, which will be described later, protrudes from each window hole 22 . Each knock projection 62 is movable in the front-rear direction along the corresponding window hole 22 .

A clip 13 is attached to the knock projection 62 positioned in the window hole 22 on the front side (FIGS. 1(A) and 1(B)). A tip portion of the clip 13 protrudes toward the rear axle 20 and contacts a clip projection 21 formed on the surface of the rear axle 20 (FIG. 1(B)). The knock rod 60 provided with the clip 13 is connected to the rear end of a refill 70 containing a thermochromic ink (to be described later) in an ink containing tube, and having a friction tool made of an elastomer material as a writing tip. On the other hand, the other two knock rods 60 (see FIG. 1(C)) are connected to the rear ends of ballpoint pen refills 80 having different ink colors. That is, the compound writing instrument 10 according to the present embodiment incorporates three types of refills.

(2) Refill, inner cylinder 30 and guide cylinder 17
FIG. 2 is a cross-sectional view of the compound writing instrument 10 shown in FIG.
An inner cylinder 30 is attached to the rear side of the internal space of the rear axle 20 to accommodate the knock bars 60 and to guide the sliding of the knock bars 60 in the front-rear direction. A guide cylinder 17 for guiding the movement of each refill in the front-rear direction is mounted on the tip side of the inner cylinder 30 . The guide tube 17 is provided with a total of three guide holes 18 through which the refills are inserted.

At the tip of the knock rod 60 to which the clip 13 is attached, the refill 70 made of an elastomer material and equipped with a friction member capable of easily changing the color of the thermochromic ink is attached as described above. This refill 70 has a structure in which a tip writing part 72 is connected to the tip of an ink connection tube 71 by a friction tool made of an elastomer material. The thermochromic ink maintains a predetermined color (first color) at room temperature (eg, 25° C.) and changes to another color (second color) when heated to a predetermined temperature (eg, 65° C.). It is an ink that changes and then returns to the original color (first color) when cooled to a predetermined temperature (eg -10°C). In general, the second color may be colorless, and the drawing line drawn with the first color (for example, red) may be heated to become colorless. Therefore, the paper surface or the like on which the drawn line is written is rubbed with the friction tool to generate frictional heat, thereby changing the drawn line colorless. It should be noted that, of course, the second color may be colored other than colorless.
In addition, a spring 90 is fitted around the rear periphery of the refill 70 having a tip writing portion with a friction tool. The rear end of the spring 90 contacts the step 68 at the tip of the knock rod 60, and the tip of the spring 90 contacts the step 19 at the tip of the guide hole 18. , the spring 90 is compressed between these steps 68,19.

On the other hand, the tips of the other two knock rods 60 are respectively fitted with ballpoint pen refills 80 as described above. The ball-point pen refill 80 has a structure in which a ball-point pen tip 82 as a tip writing portion is connected to the tip of a tubular ink storage tube 81 that stores ink. One of the ink containing tubes 81 contains a thermochromic ink that can be discolored by a friction tool, and the other contains a non-thermochromic ink that cannot be easily discolored by a friction tool. It is possible to provide a writing utensil in which a refill is housed in a metal barrel that does not have a friction tool on the outer surface of the barrel. A spring 90 is also fitted around the rear periphery of the ball-point pen refill 80, and this spring 90 is the same as that of the refill 70 having a tip writing portion with a friction tool. A cushion material 14 is interposed between the rear end portion of the inner cylinder 30 and the inner side of the rear end of the shaft cylinder 11, which will be described later.

(3) Rear axle 20
The rear axle 20 is made of a metal or resin material, and as described above, the rear axle 20 is provided with three window holes 22 (FIGS. 3A, 3B, and 4). Of these, the rear end portions of both side edges of the window hole 22 positioned on the front face each other, and these portions form a pair of engaging pieces 23 (FIGS. 3A and 4). . The rear edge of the window hole 22 is also provided with a similar projecting portion to connect the engaging pieces 23 on both sides (Fig. 3(A)).
A female screw 24 for screwing with the front barrel 40 is formed on the inner periphery near the tip of the rear barrel 20 . Further, the rear end of the internal space of the rear axle 20 forms a pedestal-shaped portion 25 projecting slightly toward the tip, and the tip surface thereof is flat. This flat surface is the rear axle rear end surface 26 (FIGS. 3(C) and 4), which is the surface with which the aforementioned cushion material 14 abuts. This will be discussed later.

(4) Inner cylinder 30
The inner cylinder 30 also has a total of three openings 31 corresponding to and continuous with the window holes 22 of the rear shaft 20 (FIGS. 5(A) to 5(D)). Along both side edges of each opening 31, rails 32 for guiding the sliding of the knock bar 60 in the front-rear direction are provided (FIGS. 5(A) to 5(D)). The tip portion of each rail 32 is sunken in the axial direction, and this portion is called a rail step 33 (FIGS. 5(A) to 5(D)).
The leading end edge 34 of the inner cylinder 30 is a portion where the leading end portion of the knock rod 60 engages, as will be described later.
A rear end recess 35 into which the cushion material 14 is inserted is formed at the rear end of the inner cylinder 30 . This will be discussed later.

(5) Front barrel 40
The inside of the front barrel 40 is made of a relatively hard resin material 41 such as polycarbonate resin, and the outside of the front barrel 40 is a grip portion 42 made of a metal material different from that of the rear barrel 20. (FIGS. 6A and 6B). A male screw 43 to be screwed into the rear shaft 20 is formed on the outer periphery of the rear end portion made of hard resin inside (FIGS. 6A and 6B).
A female thread 44 is formed on the inner circumference of the tip portion of the hard resin material 41 so that the rear end portion of a mouthpiece 50 as a tip member is screwed (FIG. 6(B)).

(6) Base 50
The mouthpiece 50 is made of metal, and has a tapered portion 51 on the tip end side. A male thread 53 is formed for this purpose (FIGS. 7A and 7B). A tip opening 52 is formed at the tip of the tapered portion 51 (FIG. 7(B)), through which the tip writing part of each refill protrudes.

The mouthpiece 50 can employ one obtained by coating the base material with nickel plating.
However, there is a concern that nickel plating may cause allergic symptoms (so-called metal allergy) by dissolving nickel under the influence of perspiration of the user.
Therefore, after nickel plating is applied, for example, an alloy coating of tin and cobalt (tin-cobalt plating) is formed as a coat layer on the nickel plating, thereby effectively preventing the dissolution of nickel in the nickel plating layer due to perspiration. be able to. As a result, it is possible to provide a writing utensil that eliminates the problem of causing allergic symptoms. In addition, it can also be applied to the barrel tube 11 (the front barrel 40 and the rear barrel 20).

(7) Knock bar 60
FIG. 8 shows the knock bar 60 to which the clip 13 is attached. The knock rod 60 has a knock rod inserting portion 61 (FIGS. 8A to 8C) which is inserted into the window hole 22 of the rear shaft 20 and the opening 31 of the inner cylinder 30 from the outside toward the front end. and a knocking projection 62 (FIG. 8(B)) located behind it and protruding outward.
A clip attachment portion 63 to which the clip 13 is attached protrudes further outward from the knock projection 62 (FIGS. 8(A) and (B)). A pair of engagement grooves 64 are formed at both rear ends of the base of the knock projection 62 (FIGS. 8(B) and 9).
After inserting the tip portion side of the knock rod 60 into the window hole 22 of the rear axle 20 and the opening 31 of the inner cylinder 30 from the outside, and then moving it slightly rearward along the rail 32, as shown in FIG. 2, the engaging pieces 23 of the window holes 22 are fitted into these engaging grooves 64 to prevent the knock rod 60 from falling outward. That is, the engaging piece 23 of the window hole 22 functions as a retainer for the knock rod 60. As shown in FIG.

The reason why the knock rod 60 is inserted from the outside of the window hole 22 of the rear axle 20 is that the inner cylinder 30 and the guide cylinder 17 are inserted into the interior of the rear axle 20 . This is because there is not enough space for inserting the knock rod 60 rearward from the tip of the .
On the other hand, a locking projection 65 projecting outward is formed at the tip of the knock rod insertion portion 61 (FIG. 8(B)). A locking step 66 positioned behind the locking projection 65 engages with the tip end edge 34 of the inner cylinder 30 (see FIG. 2), which also contributes to preventing the knock rod 60 from coming off. .

Inside the knock bar 60, a release projection 69 is formed extending in the longitudinal direction and protruding inward (FIGS. 8(B) and (C)). The release projections 69 are also provided on the other two knock projections 62, and in the non-writing state shown in FIG. state.
A refill mounting portion 67 protrudes in the distal direction from the tip of the knock rod 60 (FIGS. 8A to 8C). The refill mounting portion 67 is press-fitted to the rear end of a refill 70 having a friction tool made of an elastomer material (see FIG. 2).

(8) Cushion material 14
As shown in FIG. 11, the cushion material 14 has a substantially truncated cone-shaped convex portion 15 that tapers slightly toward the tip, and a disk-shaped plate portion 16 that continues to the rear end. It is a member that is integrally molded with. The convex portion 15 of the cushion material 14 is inserted into the rear end concave portion 35 (see FIG. 5(D)) of the inner cylinder 30 . The plate-like portion 16 abuts on the rear shaft rear end surface 26 (see FIG. 3C) of the platform portion 25 of the rear shaft 20 . That is, the cushion material 14 is a member interposed between the inner cylinder 30 and the rear axle 20 . A shallow circular first recess 27 is formed at the rear end of the rear axle 20, and a deeper circular second recess 28 concentrically formed therein. A circular seal member 29 is fitted in the first recess 27 .
A rounded chamfered portion 27A is formed on the periphery of the first recessed portion 27, and a groove having a substantially V-shaped cross section is formed around the chamfered portion 27A along with the rising portion 27C of the first recessed portion 27. This groove is called an R groove 27B.

(9) Advancement and Retreat of Refill In the state shown in FIG. intruded. From this state, when the knock rod 60 with the clip 13 attached thereto is pushed forward, the spring 90 is compressed and the knock rod 60 moves forward along the rail 32 (see FIG. 5A) of the inner cylinder 30. Moving. Then, when reaching the rail step 33 at the tip of the rail 32, the knock rod 60 sinks in the axial direction. In this state, as shown in FIG. 12, the tip writing portion 72 of the refill 70 by the friction tool protrudes from the tip opening 52 (see FIG. 7(B)) of the mouthpiece 50 to be ready for writing. At this time, the release projection 69 of the knock bar 60 is engaged with the rail step 33 . This engagement maintains the protruding state of the writing tip 72 against the biasing force of the compressed spring 90 .

In this state, when one of the other two knock bars 60 is pushed forward, the tip of the release projection 69 provided on the corresponding knock bar 60 sinks in the axial direction as described above, thereby forming a rail step. The rear end of the release projection 69 engaged with 33 is contacted and flipped up in the outer peripheral direction. As a result, the engagement between the release projection 69 and the rail step 33 is released. Then, the knock rod 60 is moved rearward by the biasing force of the compressed spring 90, and the protruding tip writing portion is retracted into the barrel 11 to return to the state shown in FIG. At this time, the knock bar 60 is positioned at the rearmost end, and at this time, the engaging piece 23 of the window hole 22 of the rear axle 20 is again fitted into the engaging groove 64 of the knock bar 60 .

(10) Effect of the cushioning material 14 Here, even if the frequency of use of a specific refill (for example, the refill 70 having the writing tip 72 with a friction tool) is extremely higher than that of other ballpoint pen refills 80, It will function as follows.
That is, even if the knock rod 60 attached to the refill is released from the writable state and collides backward due to the biasing force of the spring 90, the knock rod 60 does not directly collide with the cushion material 14.例文帳に追加That is, the knock rod 60 collides with the inner cylinder 30 in which it is accommodated. Therefore, the impact accompanying the retreating of a specific refill is dispersed into a force pushing the entire inner cylinder 30 rearward, and the dispersed force is the cushion material 14 interposed between the inner cylinder 30 and the rear axle 20. (see FIG. 11). Therefore, only a specific position (for example, a position corresponding to such a specific refill) of the cushion material 14 is not worn out.

In the dual writing instrument described above, the refills 70 and 80 accommodated in the barrel 11 are replaceable. It is desirable to replace the refills 70 and 80 with the front barrel 40 removed from the rear barrel 20 .
However, in the compound writing instrument shown in this embodiment, a mouthpiece 50 as a tip member is attached to the front end portion of the front barrel 40, and both are screwed together using a female screw 44 and a male screw 53. there is
Therefore, a user who is unaccustomed to exchanging refills may attempt to exchange the refill while removing the cap 50 from the front barrel 40 . According to this, the refill is removed from the refill mounting portion 67 of the knock rod 60 by pinching only the tip portion of the refill slightly protruding from the front barrel 40, and a new refill is attached to the knock rod 60 away from the user's hand. It is difficult to replace the refill because it is unavoidable to operate to put it on in the state.

Therefore, in the compound writing instrument according to this embodiment, the direction of rotation of the screw for releasing the connection of the front barrel 40 with respect to the rear barrel 20 and the direction of rotation of the screw for releasing the connection of the base 50 with respect to the front barrel 40 are opposite to each other. It is configured to be directional.
That is, in this embodiment, in order to release the male thread 43 of the front barrel 40 screwed from the female thread 24 of the rear barrel 20, the front barrel 40 is rotated counterclockwise with respect to the rear barrel 20. By doing so, the connection can be released. On the other hand, in order to release the male thread 53 of the mouthpiece 50 screwed from the female thread 44 of the front barrel 40 , it is necessary to rotate the mouthpiece 50 to the right with respect to the front barrel 40 .

In general, it is customary to turn the side to be removed counterclockwise to release the threaded state of the screw. The front barrel 40 is not disconnected from the rear barrel 20 by receiving the turning force.
Therefore, by setting the direction of rotation for releasing the connection of the screw as described above, most users inevitably detached the front barrel 40 from the rear barrel 20 when replacing the refill. state, the exchange operation will be performed.

On the other hand, in this compound writing instrument, a film is formed as a protective film on the surfaces of the front barrel 40 and the rear barrel 20 that constitute the barrel 11 in order to meet the user's high-end taste.
As this film formation , a film formation process by ion plating is desirable in order to bring out a deep metallic luster and to obtain a grip feeling. Moreover, it is desirable that the film thickness is 0.5 to 5 μm.
Table 1 shows the characteristics of film formation processing by ion plating (IP) and film formation processing by normal plating on the barrel 11. From Table 1, film formation processing with a hardness of Hv 700 or more was performed. In the example, it can be understood that a film excellent in durability including corrosion resistance, wear resistance and weather resistance can be obtained. Regarding the durability shown in Table 1, A indicates excellent, B indicates good, and C indicates fair.
It can be said that the higher the hardness of the film obtained by this type of film forming process, the better the durability.

By the way, in the above-mentioned dual-type writing instruments, the film on the surface tends to have a low coefficient of friction, and this causes slippage with the fingertips when gripping the barrel, resulting in a poor grip feeling. Therefore, the results of comparing the coefficient of friction between the Cr-plated shaft cylinder, which can be subjected to a film-forming process with a hardness of Hv700 or higher and which can obtain a certain level of durability, and the ion-plated shaft cylinder, are shown in Table 1. 2 and Table 3.
Table 3 shows an example of forming a film of TIN (titanium nitride) on Cr plating by ion plating.

In the measurements shown in Tables 2 and 3, the coefficient of friction between the surface of the grip portion 42 of the front barrel 40 shown in FIG. A measuring instrument (HEIDON-13D, Shinto Kagaku Co., Ltd.) is used. Then, the front barrel 40 was brought into contact with the surface of the paper with a load of 2.5 N, and the frictional resistance was measured under conditions of a speed of 20 cm/sec and a measurement distance of 20 cm to obtain a friction coefficient.
The "Y direction" shown in Tables 2 and 3 is the result when the front barrel 40 is moved on the paper surface along the axial direction, and the "X direction" is the result when the front barrel 40 is moved in the axial direction. This is the result when moving on the paper surface along the orthogonal direction.

As shown in Tables 2 and 3 above, the results of three measurements are shown for each sample, "Ave" indicates the average value of the three measurements, and "Max" indicates the results of the three measurements. The maximum value among them is shown, and "Min" shows the minimum value among the three measurement results.
As shown in the results in Tables 2 and 3, no difference was observed in the friction directions measured separately in the "Y direction" and the "X direction". All of the ion-plated (IP) barrels shown in Fig. 1 can have a high coefficient of friction.

Furthermore, with regard to the sample products that were measured, the Cr-plated shaft cylinder and the ion-plated shaft cylinder were actually gripped. can be done.
Therefore, from the comparison results shown in Tables 2 and 3, it can be found that it is appropriate to set the friction coefficient to 0.23 or more in writing instruments having this type of film on the barrel. . In addition, it can be said that the greater the friction coefficient of the film formed on the barrel, the better the grip feeling. It is desirable to

On the other hand, in the writing instrument in which the film is formed on the front barrel 40 and the rear barrel 20 as described above, it is preferable to maintain the same color difference between the front and rear barrels.
In this case, the color difference between the film formed on the front barrel 40 and the film formed on the rear barrel 20 is 20 or less in the L*a*b* color system, and the a* value is 10 or less, and the difference in b* value is 10 or less.
As a result, the difference in brightness indicated by the L* value is moderately suppressed, and the difference in color between red and green indicated by the a* value and between yellow and blue indicated by the b* value It is possible to provide a writing utensil in which the difference in color tone is also moderately suppressed, and the color tone is well-balanced in the axial direction.

As a method for measuring the shaft color of the front barrel 40 and the rear barrel 20, after photographing the surface of the component with a scanner, the screen is printed on paper and measured using a color difference meter or the like. In this case, as for the imaging conditions of the scanner, the measuring instrument is a commercially available scanner (EPSON Co. GT-X750), and the scanning is performed using the software attached to the scanner (EPSON Scan).
Mode: Home Mode,
Manuscript type: illustration,
Image type: color,
Output settings: other,
Resolution: 400dpi
Save file format: Bitmap,
Other settings: As default,
and
The image captured by the scanner is printed on a paper surface such as photographic paper, and the printed color is measured in accordance with JIS K 7375, and is measured using a general-purpose color difference meter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.). can do.

10 writing implements (dual writing implements)
11 Axle tube 12 Ring member 13 Clip 14 Cushion material 17 Guide tube 18 Guide hole 20 Rear shaft 21 Clip protrusion 22 Window hole 23 Engagement piece 24 Female screw 30 Inner tube 31 Opening 32 Rail 33 Rail step 40 Front shaft 41 Resin material 42 Grip Part 43 Male Thread 44 Female Thread 50 Base 51 Tapered Part 52 Tip Opening 53 Male Thread 60 Knock Bar 61 Knock Bar Insertion Portion 62 Knock Protrusion 63 Clip Mounting Portion 64 Engagement Groove 65 Locking Protrusion 67 Refill Mounting Portion 69 Release Protrusion 70 Refill provided with friction tool 71 Lead housing tube 72 Tip writing part (friction tool)
80 ballpoint pen refill 81 ink storage tube 82 tip writing part (ballpoint pen tip)
90 Spring

Claims (2)

A writing instrument comprising a barrel having a surface coated with a film , and a refill having a writing part housed in the barrel and protruding from the front end of the barrel,
The hardness of the film formed by ion plating TIN (titanium nitride) on the Cr plating applied to the barrel is Hv 1800 or more, the contact load of the film on the paper surface is 2.5 N, and the sliding speed is The friction coefficient is 0.25 or more when the is 20 cm / sec,
The barrel is composed of a front barrel and a rear barrel, which are detachably connected by a combination of a male screw and a female screw. It is detachably coupled by a combination of screws, the rotation direction for releasing coupling of the screw of the front barrel with respect to the rear barrel is set to counterclockwise rotation, and the rotation of coupling release of the screw of the tip with respect to the front barrel is set. A writing instrument, characterized in that the direction is set to rotate clockwise . The barrel is composed of a front barrel and a rear barrel whose outsides are made of different materials. The color difference between the film formed on the outside of the front barrel and the film formed on the rear barrel is L*a* 2. The method according to claim 1, wherein the difference in L* value is 20 or less, the difference in a* value is 10 or less, and the difference in b* value is 10 or less in the b* color system. Writing instrument.

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