JP2021175615A - Writing instrument - Google Patents

Abstract

To provide a writing instrument which improves the durability of a barrel and improves grip feeling by applying a metallic coating having a high hardness and an appropriate friction coefficient to the barrel.SOLUTION: There is provided a writing instrument 10 comprising a barrel 11 having a metal coating on its surface, and refills 70, 80 having writing portions 72, 82 which are accommodated in the barrel 11 and protrude from the front end of the barrel. The hardness of the metallic coating applied to the barrel is Hv 700 or more, and the friction coefficient when the contact load against the paper surface of the metal coating is 2.5 N and the sliding speed is 20 cm/sec is set to 0.23 or more.SELECTED DRAWING: Figure 2

Description

The present invention relates to an improvement of a writing tool having an appropriate friction coefficient on the surface of a barrel and having a protective film having a high hardness, which is excellent in high-class feeling and durability.

Ballpoint pens, mechanical pencils, or compound writing instruments in which a plurality of cursive bodies are housed in a barrel are devised to give a beautiful impression by adding decoration to the surface of the barrel.
In this case, as a relatively low-priced writing tool, one in which the barrel is directly painted, transferred, printed, plated, or otherwise decorated (see Patent Document 1) has been proposed.
Further, it has been proposed that a transfer film formed by color printing or the like is laminated on the surface of the barrel (see Patent Document 2).

However, the writing tools disclosed in Patent Document 1 have problems such as poor wear resistance and corrosion resistance of the decorative portion, and the base of the barrel is exposed and becomes unsightly with the lapse of use time. ing.
Further, in the writing tool disclosed in Patent Document 2, since the film to which the color printing is transferred is attached to the shaft cylinder, the film may be peeled off with use, or the shaft cylinder may be slippery and lack a grit feeling. Etc. have problems.

Therefore, in order to ensure the durability of the surface of the barrel, a writing instrument in which a protective film (metal coating) having a high hardness is applied to the barrel has been proposed (see Patent Document 3).
According to the writing tool shown in Patent Document 3, the high-hardness metal coating is accompanied by a deep luster, which can contribute to improving the quality of appearance and giving the writing tool a sense of quality.

International Publication 2013/008811 Japanese Unexamined Patent Publication No. 2010-253842 Jitsukaisho 60-173380

By the way, according to the writing tool disclosed in Patent Document 3, although the high hardness metal coating can contribute to improving the durability of the shaft cylinder, it is slippery due to the low friction coefficient of the metal coating, which hinders accurate writing. There are technical issues such as

Therefore, in the present invention, the durability of the shaft cylinder can be improved by applying a metal coating having a high hardness to the shaft cylinder, and the problem of slipperiness can be solved by providing an appropriate friction coefficient in the metal coating to solve the problem of slipperiness. This is an attempt to provide a writing tool having an excellent appearance with a glossy appearance and an excellent appearance.

The writing tool according to the present invention made to solve the above-mentioned problems includes a shaft cylinder having a metal coating on the surface, and a writing portion housed in the shaft cylinder and protruding from the front end portion of the shaft cylinder. When the hardness of the metal coating applied to the barrel is Hv700 or more, the contact load of the metal coating on the paper surface is 2.5 N, and the sliding speed is 20 cm / sec. The friction coefficient of The tip of the mouth is detachably connected to the portion by a combination of a male screw and a female screw, and the rotation direction of disengagement of the screw of the front shaft with respect to the rear shaft and the screw of the mouth with respect to the front shaft. It is characterized in that the rotation directions of the disengagement of the screws are configured to be opposite to each other. The 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 (currently Mitutoyo)).

In this case, the axle is composed of a front shaft and a rear shaft, which are made of different materials on the outside, and the color difference between the metal coating applied to the outside of the front shaft and the metal coating applied to the rear shaft is L *. In the a * b * color system, the difference between the L * values is 20 or less, the difference between the a * values is 10 or less, and the difference between the b * values is 10 or less.

Further, a configuration in which a nickel-plated layer is formed on the material forming the barrel and a coat layer is further formed on the nickel-plated layer can be preferably adopted.

According to the writing tool according to the present invention, the hardness of the metal coating applied to the barrel and the friction coefficient of the metal coating are set within the above-mentioned specific ranges, so that the durability of the metal coating is excellent and the friction coefficient is appropriate. It is possible to provide a writing tool that can obtain a feeling of grip.
Then, in a writing tool in which the axle cylinder is composed of a front shaft and a rear shaft, the color difference of the metal coating applied to the front shaft and the rear shaft is within the above-mentioned range indicated by the L * a * b * color system. By setting, it is possible to provide a writing tool having a well-balanced brightness and color tone.
As a result, it is possible to provide a writing tool having a deep metallic luster that can meet the high-class taste of the user.

It is (A) front view, (B) right side view, (C) back view of the compound writing instrument which concerns on embodiment of this invention. It is a central sectional view of the compound writing instrument shown in FIG. It is (A) front view, (B) right side view, (C) cross-sectional view of the rear shaft used for the compound writing tool shown in FIG. It is an enlarged cross-sectional view seen in the direction of an arrow from line IV-IV in FIG. 3C. It is (A) front view, (B) right side view, (C) rear view, (D) sectional view of the inner cylinder used for the compound writing tool shown in FIG. It is (A) front view and (B) sectional view of the leading shaft used for the compound writing tool shown in FIG. It is (A) front view and (B) sectional view of the base used for the compound writing tool shown in FIG. It is (A) front view, (B) right side view, (C) back view of the knock bar used for the compound writing tool shown in FIG. 8 is an enlarged cross-sectional view taken in the direction of the arrow from the IX-IX line in FIG. 8B. It is an enlarged cross-sectional view seen in the direction of an arrow from the X-ray line in FIG. It is an enlarged view of the crown part of the compound writing instrument shown in FIG. It is sectional drawing which shows the state which one writing part protruded in the compound writing instrument shown in FIG.

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 Tool The writing tool according to the embodiment is a compound writing tool 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 the plurality of refills housed inside the compound writing tool 10 are all immersed.
In the axle cylinder 11, the rear shaft 20 located on the rear end side and the front shaft 40 located on the front end side are screwed and connected to each other. The ring member 12 is remodeled between the rear axle 20 and the front axle 40. Further, a mouthpiece 50 as a mouthpiece is screwed and attached to the tip of the tip shaft 40.
The rear shaft 20 is made of a metal material, and three window holes 22 which are openings in the longitudinal direction are provided at the rear portion. A knock protrusion 62 provided on the outer surface of the knock rod 60 mounted behind the 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.

Further, a clip 13 is attached to the knock protrusion 62 located in the window hole 22 on the front side (FIGS. 1A and 1B). The tip portion of the clip 13 projects toward the rear shaft 20 and is in contact with the clip protrusion 21 formed on the surface of the rear shaft 20 (FIG. 1 (B)). The knock rod 60 provided with the clip 13 stores the heat-discoloring ink described later in the ink storage tube, and is connected to the rear end of the refill 70 provided with a friction tool made of an elastomer material as a tip writing portion. On the other hand, the other two knock rods 60 (see FIG. 1C) are connected to the rear ends of the ballpoint pen refills 80, which have different ink colors and will be described later. That is, the compound writing tool 10 according to the present embodiment contains three types of refills.

(2) Refill, inner cylinder 30, guide cylinder 17
FIG. 2 is a cross-sectional view of the compound writing tool 10 shown in FIG.
On the rear side of the internal space of the rear shaft 20, an inner cylinder 30 that accommodates each knock rod 60 and guides the slide of these knock rods 60 in the front-rear direction is mounted. A guide cylinder 17 that guides the movement of each refill in the front-rear direction is mounted on the tip side of the inner cylinder 30. The guide cylinder 17 is provided with a total of three guide holes 18 through which each refill is inserted.

As described above, a refill 70 made of an elastomer material and equipped with a friction tool capable of easily discoloring heat-discoloring ink is attached to the tip of the knock rod 60 to which the clip 13 is attached. The refill 70 has a structure in which a tip writing portion 72 made of an elastomer material friction tool is connected to the tip of the ink connecting tube 71. The thermochromic ink maintains a predetermined color (first color) at room temperature (for example, 25 ° C.), and changes to another color (second color) when the temperature is raised to a predetermined temperature (for example, 65 ° C.). An ink that has the property of changing and then returning to its original color (first color) when cooled to a predetermined temperature (for example, −10 ° C.). Generally, the second color may be colorless, and the drawn line drawn with the first color (for example, red) may be heated to make it colorless. Therefore, the drawn line is rubbed against the written paper surface or the like by a friction tool to generate frictional heat, thereby changing the drawn line to colorless. As a matter of course, the second color may be a color other than colorless.
Further, a spring 90 is extrapolated to the rear outer periphery of the refill 70 provided with the tip writing portion by the friction tool. The rear end of the spring 90 is in contact with the step 68 at the tip of the knock rod 60, and the tip of the spring 90 is in contact with the step 19 at the tip of the guide hole 18, as the knock rod 60 slides toward the tip. , The spring 90 is compressed between these steps 68, 19.

On the other hand, ballpoint pen refills 80 are attached to the tips of the other two knock rods 60 as described above. The ballpoint pen refill 80 has a structure in which a ballpoint pen tip 82 as a tip writing portion is connected to the tip of a tubular ink storage tube 81 that stores ink. The ink storage tube 81 contains one heat-discolorable ink that can be discolored by a friction tool, and the other non-heat-discolorable ink that cannot be easily discolored by a friction tool, and is switched depending on the usage conditions. It is possible to provide a writing tool in which a refill is housed in a metal shaft having no friction tool on the outer surface of a simple shaft cylinder. A spring 90 is also extrapolated to the rear outer periphery of the ballpoint pen refill 80, and the spring 90 is the same as the refill 70 provided with the tip writing portion by the friction tool described above. A cushion material 14 is interposed between the rear end portion of the inner cylinder 30 and the inside of the rear end of the shaft cylinder 11, which will be described later.

(3) Rear axle 20
The rear shaft 20 is made of a metal or resin material, and as described above, the rear shaft 20 is provided with three window holes 22 (FIGS. 3 (A) and (B) and FIG. 4). Among them, the rear end portions of both side edges of the window hole 22 located in the front project so as to face each other, and these portions form a pair of engaging pieces 23 (FIGS. 3 (A) and 4). .. A similar overhanging portion is also provided on the rear end edge of the window hole 22 to connect the engaging pieces 23 on both sides (FIG. 3 (A)).
A female screw 24 for screwing with the front shaft 40 is formed on the inner circumference near the tip of the rear shaft 20. Further, the rear end of the internal space of the rear shaft 20 is a trapezoidal portion 25 protruding slightly toward the tip end in a trapezoidal shape, 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 cushion material 14 described above comes into contact. This will be described later.

(4) Inner cylinder 30
The inner cylinder 30 is also provided with a total of three openings 31 corresponding to and continuous with each window hole 22 of the rear shaft 20 (FIGS. 5A to 5D). Rails 32 for guiding the slide of the knock rod 60 in the front-rear direction are provided along both side edges of each opening 31 (FIGS. 5A to 5D). The tip portion of each rail 32 is sunk in the axial direction, and this portion is referred to as a rail step 33 (FIGS. 5A to 5D).
As will be described later, the tip edge 34 of the inner cylinder 30 is a place where the tip portion of the knock rod 60 is locked, which 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 described later.

(5) Lead shaft 40
The front shaft 40 has a structure in which the inside thereof is molded of a relatively hard resin material 41 such as polycarbonate resin, and the grip portion 42 made of a metal material using a material different from that of the rear shaft 20 is located on the outside thereof. (FIGS. 6 (A) and 6 (B)). A male screw 43 screwed into the rear shaft 20 is formed on the outer periphery of the rear end portion made of the inner hard resin (FIGS. 6A and 6B).
Further, a female screw 44 is formed on the inner circumference of the tip portion of the hard resin material 41 so that the rear end portion of the mouthpiece 50 as a mouthpiece member is screwed in (FIG. 6 (B)).

(6) Base 50
The base 50 is made of metal, and the tip side is a tapered portion 51 formed tapered, and the outer periphery of the substantially tubular portion on the rear end side is screwed into the female screw 44 of the tip shaft 40. Therefore, a male screw 53 is formed (FIGS. 7A and 7B). A tip opening 52 is formed at the tip of the tapered portion 51 (FIG. 7B), from which the tip writing portion of each refill appears and disappears.

As the base 50, a base material coated with nickel plating can be adopted.
However, nickel plating may be affected by the sweating of the user and dissolve nickel to cause allergic symptoms (so-called metal allergies).
Therefore, after nickel plating, for example, an alloy coating of tin and cobalt (tin Koba plating) is formed as a coating layer on the nickel plating to effectively prevent the dissolution of nickel in the nickel plating layer due to sweating. be able to. This makes it possible to provide a writing tool that solves the problem of causing allergic symptoms. It can also be applied to the axle cylinder 11 (front shaft 40 and rear shaft 20).

(7) Knock rod 60
FIG. 8 shows a knock rod 60 to which the clip 13 is attached. The knock rod 60 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 tip end (FIGS. 8A to 8C). And a knock protrusion 62 (FIG. 8 (B)) located behind the knock protrusion 62 (FIG. 8 (B)) that protrudes outward.
A clip mounting portion 63 to which the clip 13 is mounted protrudes further outward of the knock protrusion 62 (FIGS. 8A and 8B). Further, engagement grooves 64, which are a pair of grooves, are formed at the rear ends on both sides of the root of the knock protrusion 62 (FIGS. 8 (B) and 9).
When the tip end side of the knock rod 60 is inserted into the window hole 22 of the rear shaft 20 and the opening 31 of the inner cylinder 30 from the outside and then moved slightly rearward along the rail 32, FIG. As shown in the above, the engaging piece 23 of the window hole 22 is fitted into these engaging grooves 64, and the knock rod 60 is prevented from falling out. That is, the engaging piece 23 of the window hole 22 functions as a stopper for the knock rod 60.

The knock rod 60 is attached by inserting the knock rod 60 from the outside of the window hole 22 of the rear shaft 20 because the inner cylinder 30 and the guide cylinder 17 are inserted inside the rear shaft 20. This is because there is not enough space for inserting the knock rod 60 from the tip to the rear.
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)). The locking step 66 located behind the locking projection 65 locks with the tip edge 34 of the inner cylinder 30 described above (see FIG. 2), which also contributes to preventing the knock rod 60 from coming off. ..

Inside the knock rod 60, a release protrusion 69 is formed so as to extend inward while being installed along the longitudinal direction (FIGS. 8B and 8C). The release protrusion 69 is also provided on the other two knock protrusions 62, and in the non-writing state shown in FIG. 1, each release protrusion 69 is abutted toward the axial center as shown in FIG. It is in a state.
From the tip of the knock rod 60, the refill mounting portion 67 projects toward the tip (FIGS. 8A to 8C). The refill mounting portion 67 is press-fitted into the rear end of the refill 70 provided with 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 is slightly tapered toward the tip, and a disk-shaped plate-shaped portion 16 that is continuous at the rear end, and is made of silicon rubber. It is a member integrally molded with. Of the cushion material 14, the convex portion 15 is inserted into the rear end concave portion 35 (see FIG. 5D) of the inner cylinder 30. Further, the plate-shaped portion 16 comes into contact with the rear shaft rear end surface 26 (see FIG. 3C) of the trapezoidal portion 25 on the rear shaft 20. That is, the cushion material 14 is a member interposed between the inner cylinder 30 and the rear shaft 20. A shallow circular first recess 27 is formed at the rear end of the rear shaft 20, and a deeper circular second recess 28 having the same center as the first recess 27 is also formed therein. A circular seal member 29 is fitted in the first recess 27.
Here, a chamfered portion 27A having a radius is formed on the peripheral edge of the first recess 27, and a groove having a substantially V-shaped cross section is formed around the chamfered portion 27A with the rising portion 27C of the first recess 27. It is formed, and this groove is referred to as a rounded groove 27B.

(9) Forward and backward refills In the state shown in FIG. 2, the knock rod 60 is located at the rearmost end, and the engaging piece 23 of the window hole 22 of the rear shaft 20 is located in the engaging groove 64 of the knock rod 60. It is fitted. From this state, when the knock rod 60 to which the clip 13 is attached is pressed toward the tip, the knock rod 60 moves forward along the rail 32 of the inner cylinder 30 (see FIG. 5 (A)) while compressing the spring 90. Moving. Then, when the rail step 33 at the tip of the rail 32 is reached, 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. 7B) of the mouthpiece 50, and the refill 70 is in a writable state. At this time, the release protrusion 69 of the knock rod 60 is engaged with the rail step 33. By this engagement, the state in which the tip writing portion 72 is projected is maintained against the urging force of the compressed spring 90.

In this state, when either of the other two knock rods 60 is pressed toward the tip end, the tip end of the release protrusion 69 provided on the knock rod 60 sinks in the axial direction as described above, and the rail step It comes into contact with the rear end of the release protrusion 69 that is engaged with 33, and is flipped up in the outer peripheral direction. As a result, the engagement between the release protrusion 69 and the rail step 33 is disengaged. Then, the knock rod 60 moves rearward by the urging force of the compressed spring 90, and the protruding tip writing portion immerses in the inside of the barrel 11 and returns to the state shown in FIG. At this time, the knock rod 60 is located at the rearmost end, and at that time, the engaging piece 23 of the window hole 22 of the rear shaft 20 is fitted into the engaging groove 64 of the knock rod 60 again.

(10) Action of Cushion Material 14 Here, even when a specific refill (for example, a refill 70 having a tip writing portion 72 with a friction tool) is used more frequently than other ballpoint pen refills 80, It will function as follows.
That is, even if the knock rod 60 attached to the refill collides rearward due to the urging force of the spring 90 due to the release from the writable state, the knock rod 60 does not directly collide with the cushion material 14. That is, the knock rod 60 collides with the inner cylinder 30 in which the knock rod 60 is housed. Therefore, the impact caused by the retreat of the specific refill is dispersed to the force that pushes the entire inner cylinder 30 backward, and the dispersed force is distributed between the inner cylinder 30 and the rear shaft 20 (cushion material 14). (See FIG. 11). Therefore, only a specific position of the cushion material 14 (for example, a position corresponding to such a specific refill) is not reduced.

In the compound writing tool described above, the refills 70 and 80 housed in the barrel 11 can be exchanged. It is desirable to replace the refills 70 and 80 with the front axle 40 removed from the rear axle 20.
However, in the compound writing tool shown in this embodiment, a mouthpiece 50 as a mouthpiece member is attached to the tip end side of the tip shaft 40, and both are screwed together using a female screw 44 and a male screw 53. There is.
Therefore, a user who is unfamiliar with the replacement of the refill may try to replace the refill with the base 50 removed from the toe shaft 40. According to this, only the tip portion of the refill slightly protruding from the toe shaft 40 was picked, the refill was removed from the refill mounting portion 67 of the knock rod 60, and a new refill was separated from the knock rod 60. It is difficult to replace the refill because it is forced to install it in the state.

Therefore, in the compound writing tool according to this embodiment, the rotation direction of the screw for releasing the connection of the front shaft 40 with respect to the rear shaft 20 and the rotation direction of the screw for releasing the connection of the screw of the base 50 with respect to the front shaft 40 are opposite to each other. It is configured to be in the direction.
That is, in this embodiment, in order to release the connection of the male screw 43 of the front shaft 40 in a state of being screwed into the female screw 24 of the rear shaft 20, the front shaft 40 is rotated counterclockwise with respect to the rear shaft 20. By doing so, the bond can be released. On the other hand, in order to release the connection of the male screw 53 of the base 50 in the state of being screwed into the female screw 44 of the front shaft 40, it is necessary to rotate the base 50 clockwise with respect to the front shaft 40.

Generally, in order to release the screwed state with a screw, it is customary to rotate the removing side counterclockwise. On the other hand, in the above-mentioned writing tool, even if the base 50 is rotated counterclockwise, the base 50 starts from the toe shaft 40. It is not removed, and the coupling state of the front shaft 40 with respect to the rear shaft 20 is released by receiving the rotational power.
Therefore, by setting the rotation direction of screw disengagement to the above-mentioned relationship as described above, most users inevitably remove the front shaft 40 with respect to the rear shaft 20 when replacing the refill. In this state, the replacement operation will be performed.

On the other hand, in this compound writing tool, a metal coating is applied as a protective film on the surfaces of the front shaft 40 and the rear shaft 20 constituting the shaft cylinder 11 in order to meet the high-class taste of the user.
As this metal coating, a deep metallic luster can be produced, and a film formation treatment by ion plating is desirable in order to obtain a grip feeling. The film thickness is preferably 0.5 to 5 μm.
Table 1 shows the characteristics of the film formation treatment by ion plating (IP) and the film formation treatment by ordinary plating on the barrel 11, and the film formation treatment having a hardness of Hv700 or more was performed from Table 1. In the example, it can be understood that a metal coating having excellent durability including corrosion resistance, wear resistance, and weather resistance can be obtained. Regarding the durability shown in Table 1, A is excellent, B is good, and C is normal.
It can be said that the higher the hardness of the metal coating obtained by this type of film forming treatment, the more excellent the durability, and in consideration of productivity, the metal coating is more preferably in the range of Hv1500 to 3000.

By the way, in the above-mentioned compound writing tool, the metal coating on the surface tends to have a small coefficient of friction, which causes slippage with the fingertips when gripping the barrel, resulting in a problem of poor grip feeling. Therefore, the table below shows the results of comparing the friction coefficient between the Cr-plated shaft tube, which can be subjected to film formation processing with a hardness of Hv700 or higher, which can obtain a certain degree of durability, and the shaft cylinder, which is ion-plated. 2 and Table 3 show.
Table 3 shows an example in which TIN (titanium nitride) is formed 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 on the leading shaft 40 shown in FIG. 6 and the paper surface (high quality paper) is measured, and specifically, a commercially available surface is measured. A measuring instrument (HEIDON-13D, Shinto Kagaku Co., Ltd.) is used. Then, the leading shaft 40 was brought into contact with the paper surface by applying a load of 2.5 N, and the frictional resistance was measured under the 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 leading shaft 40 is moved on the paper surface along the axial direction, and the "X direction" is the axial direction of the leading shaft 40. This is the result when the paper is moved along the orthogonal direction.

As shown in Tables 2 and 3, the measurement results of each of the three measurements are shown for each sample, "Ave" indicates the average value of the three measurement results, and "Max" indicates the average value of the three measurement results. The maximum value is shown, and "Min" shows the minimum value among the three measurement results.
As shown in the results of Tables 2 and 3, there is no difference in the friction direction measured separately for the "Y direction" and the "X direction", and there is no difference in the Cr-plated shaft cylinder shown in Table 2, and Table 3 As for the shaft cylinders by ion plating (IP) shown in the above, those having a high friction coefficient can be obtained.

Furthermore, with respect to the measured sample product, it is possible to obtain the feeling that the cylinder by ion plating is not slippery and the grip is good even when the cylinder by Cr plating and the cylinder by ion plating are 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 the writing tool having this kind of metal coating on the barrel. .. It can be said that the larger the friction coefficient of the metal coating formed on the shaft cylinder, the better the grip feeling, but the friction coefficient is 0 in order to achieve both an appropriate grip feeling and the hardness of the film formation. It is desirable that the value is 6.6 or less.

On the other hand, in a writing tool in which a metal coating is formed on the front shaft 40 and the rear shaft 20 as described above, it is preferable that the front and rear color differences are similarly maintained.
In this case, the color difference between the metal coating applied to the front shaft 40 and the metal coating applied to the rear shaft 20 is 20 or less in the L * a * b * color system, and the a * value. It is desirable that the difference between the two is 10 or less and the difference between the b * values is 10 or less.
As a result, the difference in brightness indicated by the L * value is appropriately suppressed, the difference in color tone between red and green indicated by the a * value, and the difference between yellow and blue indicated by the b * value. It is possible to provide a writing tool in which the difference in color tone is appropriately suppressed and the color tone is balanced in the axial direction.

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

10 Writing tools (double writing tools)
11 Shaft cylinder 12 Ring member 13 Clip 14 Cushion material 17 Guide cylinder 18 Guide hole 20 Rear shaft 21 Clip protrusion 22 Window hole 23 Engagement piece 24 Female screw 30 Inner cylinder 31 Opening 32 Rail 33 Rail step 40 Toe shaft 41 Resin material 42 Grip 43 Male screw 44 Female screw 50 Mouthpiece 51 Tapered part 52 Tip opening 53 Male screw 60 Knock rod 61 Knock rod insertion part 62 Knock protrusion 63 Clip mounting part 64 Engagement groove 65 Locking protrusion 67 Refill mounting part 69 Release protrusion 70 Refill with friction tool 71 Core accommodation tube 72 Tip writing part (friction tool)
80 Ballpoint pen refill 81 Ink storage tube 82 Tip writing part (ballpoint pen tip)
90 spring

The writing tool according to the present invention made to solve the above-mentioned problems is a writing tool including a shaft cylinder and a refill having a writing portion housed in the shaft cylinder and protruding from the front end portion of the shaft cylinder. , before Symbol barrel is, is composed of the rear axle and front barrel, with between them is detachably coupled by a combination of the male thread and the female thread, the distal end portion of said front barrel has mouth portion, a male screw It is detachably connected by a combination of a screw and a female screw, and the rotation direction of the screw release of the front shaft with respect to the rear shaft and the rotation direction of the screw release of the mouth end with respect to the front shaft are It is characterized in that it is configured in opposite directions .

In this case, the axle is composed of a front shaft and a rear shaft, which are made of different materials on the outside, and there is a color difference between the metal coating applied to the surface of the front shaft and the metal coating applied to the surface of the rear shaft. , L * a * b * color system, the difference of L * value is 20 or less, the difference of a * value is 10 or less, and the difference of b * value is 10 or less.

In addition, a plurality of refills housed inside the barrel are provided, and a refill equipped with a friction tool capable of discoloring heat-discoloring ink is attached as a tip writing portion, and at least one of them can be discolored by the friction tool. A refill containing thermochromic ink is installed.

Further , a configuration in which an inner cylinder is mounted on the rear side of the internal space of the rear axle and a cushion material is interposed between the rear end portion of the inner cylinder and the inside of the rear end of the axle cylinder is also preferably adopted. can do.

On the other hand, in this compound writing tool, a metal coating is applied as a protective film on the surfaces of the front shaft 40 and the rear shaft 20 constituting the shaft cylinder 11 in order to meet the high-class taste of the user.
As this metal coating, a deep metallic luster can be produced, and a film formation treatment by ion plating is desirable in order to obtain a grip feeling. The film thickness is preferably 0.5 to 5 μm.
Table 1 shows the characteristics of the film formation treatment by ion plating (IP) and the film formation treatment by ordinary plating on the barrel 11, and the film formation treatment having a hardness of Hv700 or more was performed from Table 1. In the example, it can be understood that a metal coating having excellent durability including corrosion resistance, wear resistance, and weather resistance can be obtained. Regarding the durability shown in Table 1, A is excellent, B is good, and C is normal.
It can be said that the higher the hardness of the metal coating obtained by this type of film forming treatment, the more excellent the durability, and in consideration of productivity, the metal coating is more preferably in the range of Hv1500 to 3000.
The 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 (currently Mitutoyo)).

Claims (2)

A writing instrument composed of a shaft cylinder having a metal coating on its surface and a refill having a writing portion housed in the shaft cylinder and protruding from the front end portion of the shaft cylinder.
When the hardness of the metal coating applied to the barrel is Hv700 or more, the contact load of the metal coating on the paper surface is 2.5 N, and the sliding speed is 20 cm / sec, the friction coefficient is 0.23 or more. can be,
The axle is composed of a front shaft and a rear shaft, and the two are detachably connected by a combination of a male screw and a female screw, and a tip portion is attached to the tip of the front shaft, and a male screw and a female screw are used. It is detachably connected by a combination of screws, and the rotation direction of the screw release of the front shaft with respect to the rear shaft and the rotation direction of the screw release of the mouth end with respect to the front shaft are opposite to each other. A writing tool characterized by being configured in a direction. The axle is composed of a front shaft and a rear shaft, which are made of different materials on the outside, and the color difference between the metal coating applied to the outside of the front shaft and the metal coating applied to the rear shaft is L * a *. The first aspect of claim 1, wherein in the b * color system, the difference between the L * values is 20 or less, the difference between the a * values is 10 or less, and the difference between the b * values is 10 or less. Writing utensils.

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