JP2002205491A - Cap for writing utensil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap for a writing utensil, with which the sealing up state between an inner cap and a pen point part can be confirmed together with the recognition of the color of the ink of the writing utensil by a simple constitution. SOLUTION: In the cap 3 for the writing utensil, the cap is equipped with a cap main body 20 and an inner cap 22, which is arranged within the cap main body 20 and covers and protects the pen point part 8 at the tip of a writing utensil 2. In the cap main body 20, a crown part 21, in which a guide part 21j for guiding the inner cap 22 is projected, is provided at the tip side of the cap main body. The inner cap 22 is axially shiftably arranged through a coiled spring 26 at the tip side within the crown part 21. At one axial end part of the inner cap, a spring housing part 22a is provided, while, at the other end part, a pen point housing part 22b is formed. The crown part 21 is made of a transparent or semi-transparent material under the condition that a thick- walled part and a thin-walled part, the thickness of the walls of the outer peripheral wall parts of which are different from each other, are formed axially alternately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument cap, and more particularly to a writing instrument cap which is detachably mounted on a writing instrument body and has a cap body and an inner cap.

[0002]

2. Description of the Related Art In general, a writing instrument such as an oil-based ball-point pen or a water-based ball-point pen is provided with a detachable cap so as to surround and protect the front end of a writing portion when not in use.
In particular, in some writing instruments, the tip of the writing section is hermetically sealed with an inner cap so that the tip of the writing section (pen tip) is not dried out so that the ink does not dry. Are known. In many conventional writing implements, the color of the ink of the writing implement is identified by the color of the cap. Further, it is common to add a decorative component such as a crown to the cap and to add a small component of color display.

[0003]

However, when the colored cap is attached to the tip of the writing part, there is a problem that the sealed state of the pen tip cannot be confirmed. In particular,
In a writing instrument with an inner cap, if the cap body is attached to the writing instrument body with something between the inner cap and the pen tip, the tightness around the pen tip of the inner cap is maintained. Therefore, there is a problem that the pen tip dries and becomes unusable without being noticed. Further, when a small part with a crown or a color display is added, there are problems that the number of parts increases, the assembly cost increases, and further, the appearance of the assembled part is impaired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and enables the ink color of a writing instrument to be distinguished with a simple structure, to improve the appearance, and to improve the inner cap and the pen tip portion. It is an object of the present invention to provide a writing instrument cap capable of confirming a sealed state of a writing instrument.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a writing instrument cap, and more particularly to a writing instrument cap provided separately from a writing instrument body, wherein a hollow portion is formed inside and an opening is formed at one end. A cap body, and an inner cap disposed inside the cap body for covering and protecting a pen tip at the tip of the writing instrument body, wherein the cap body guides the inner cap to a tip side of a hollow portion thereof. In the writing instrument cap provided with a crown portion in which the guide portion is formed so as to protrude, the crown portion is formed of a material having visibility, and the thickness of the outer peripheral wall portion along the axial direction is reduced. This is characterized in that different thick portions and thin portions are formed.

Incidentally, the following configuration can be adopted. A writing instrument cap separately provided in a writing instrument body, wherein a cap body having a hollow portion formed therein and having an opening formed at one end, and a pen tip portion disposed inside the cap body and at the tip of the writing instrument body The cap body is provided with a crown on the tip side of the hollow portion, and the crown and the inner cap are integrally formed, and the crown is Is formed of a material having visibility, and along the axial direction,
A thick part and a thin part having different thicknesses of the outer peripheral wall are formed. With such a configuration, in addition to the effects of the invention described in claim 1,
Since the crown and the inner cap are integrally formed, the spring and the like can be eliminated, and since they can be formed by one part, there is an effect that cost can be reduced. It should be noted that the above-mentioned configuration may be further limited as specified in claims 3 and 5.

The inner cap is disposed movably in the axial direction via a coil spring at the distal end inside the crown portion, and the inner cap is provided at one end along the axial direction. Preferably, a spring accommodating portion for accommodating the spring is provided, and a pen tip accommodating portion for covering the pen tip portion is formed at the other end. Also,
It is preferable that the difference in wall thickness between the thick portion and the thin portion of the outer peripheral wall portion of the crown portion is twice or more. Further, it is preferable that the guide section includes a rib formed along the axial direction. The cap body and the crown are made of acrylic, polycarbonate, polystyrene, AS
Resin (acrylonitrile / styrene resin), ABS resin, nylon, polyolefin resin, polyethylene terephthalate, and alloys based on each of the above resins (for example,
Visible resin material including PC / PET, Co-PET (based on resin such as PET / PCT (polycyclohexanedimethanol)) (for example, transparency 8
0% or more of transparent resin material or translucent resin material, or
The transparent resin material or the translucent resin material colored)
It is preferable that

According to the present invention, in the writing instrument cap provided separately on the writing instrument main body, the crown can be formed of a transparent or translucent resin material so that the internal structure can be visually recognized. It is possible to check the state of attachment to the tip. Also, the configuration of the crown
Along the axial direction, thick and thin portions with different thicknesses of the outer peripheral wall are formed alternately, thereby enabling material reduction by thinning and partially increasing the thickness. By using meat, the required strength can be ensured. Further, when a colored resin material is used, a shaded portion of the color is formed, so that a beautiful appearance with a change in color tone can be realized.

Further, by making the wall thickness dimensional difference between the thick portion and the thin portion of the outer peripheral wall of the crown portion more than twice, the material can be reduced by the thin portion, and the strength of the required portion can be reduced. Can be secured. In addition, since the guide portion includes the rib formed along the axial direction, the material can be reduced, and the strength of a necessary portion can be secured. Further, the material of the cap body and the crown portion,
A transparent resin material having a transparency of 80% or more, such as acrylic, polycarbonate, polystyrene, AS resin, transparent ABS resin, transparent nylon, transparent polyolefin resin, polyethylene terephthalate, and alloys based on each of the above resins;
Or, by making the transparent resin material colored,
Since the internal structure can be visually checked, the state of attachment of the inner cap to the pen tip can be checked, and the color of the writing implement can be checked by changing the color of the inner cap to the same color as the ink of the writing implement to which the cap is attached. Since the identification can be achieved and the transparent cap body can be shared, the number of manufactured parts and the cost can be reduced.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 to 4 show an example of the embodiment of the present invention. FIG. 1A is an explanatory view showing the entire configuration of a writing instrument equipped with a writing instrument cap according to the embodiment of the present invention, and FIG. FIG. 2 is an explanatory view showing a configuration in a state in which the writing instrument is used, FIG. 2 is a detailed cross-sectional view showing a configuration in the vicinity of a pen tip in a state in which the writing instrument cap is mounted on the pen tip, and FIG. FIG. 4A is a detailed cross-sectional view showing a configuration of a rear end portion of the writing instrument attached to the rear end section, FIG. 4A is a side view showing a configuration of a crown portion of the writing instrument cap, and FIG. (C) is a sectional view taken along the arrow BB in (a).

The present embodiment, as shown in FIGS. 1A and 1B, is a writing implement 1 provided with a writing implement main body 2 and a writing implement cap 3 which is formed separately. The writing implement body 2
Are an ink tank 4 and a tip shaft 5 in which ink is filled.
And a rear shaft 7 on which the refill 6 is mounted. The ink tank 4 is accommodated in the rear shaft 7, and the refill 6 is detachably attached to the rear shaft 7. It is to be attached.

The ink tank 4 is made of a transparent resin so that the internal structure and ink can be visually recognized.
A screw portion 4 a is formed on an outer peripheral portion near a boundary portion between the ink tank 4 and the front shaft 5, and is screwed to the rear shaft 7. The pen tip 8 on the front side of the ink tank 4 includes:
The pen tip 8a is incorporated via the pen tip support portions 9a and 9b. An ink reservoir 10 is provided in the ink tank 4 behind the pen tip portion 8 to retain ink and prevent ink leakage.

The ink storage body 10 has a plurality of peripheral grooves formed on the outer peripheral surface as storage grooves 10a, and vertical grooves (not shown) for communicating the storage grooves 10a are formed. This vertical groove communicates with the ink chamber 11 so that when the air in the ink chamber 11 expands due to a temperature change or the like and the ink is pushed out from the ink chamber 11, the ink does not drop down from the pen tip portion 8. When the air in the ink chamber 11 shrinks and returns to the original state, the ink in the storage groove 10a returns to the ink chamber 11 temporarily. I have.

A vent 12 is formed in the center of the ink reservoir 10 in the axial direction, and an ink guide core 13 is press-fitted into the vent 12 at the rear (ink side) of the vent 12. Or it is penetrated with some gaps. Furthermore,
The tip of the ink guide core 13 is connected to the pen tip 8 so as to supply the ink in the ink chamber 11 to the pen tip 8. In addition, the ink in the ink chamber 11
A ventilation hole (not shown) communicating with the ventilation hole 12 is provided on a side surface of the ink storage body 10 in which the ventilation hole 12 for attaching the ink guide core 13 to be supplied to the ink reservoir is formed.

The outer shape of the refill 6 has a so-called stepped shape in which the outer diameter of the front shaft 5 at the front side of the screw portion 4a is larger than the outer diameter of the rear portion 4b of the ink tank 4. Present. It is formed in a tapered shape tapering toward the tip end of the front shaft 5 in a partial range from the stepped portion 5a. The shape from the screw portion 4a to the rear side portion 4b is formed in a slightly tapered shape toward the rear.

The rear shaft 7 is made of a transparent resin so that the ink tank 4 housed therein can be visually recognized, and one end 7a side is formed with an opening, and a position corresponding to the screw portion 4a is formed inside the rear shaft 7. Is formed with a screw portion 7b.
The one end 7a has an outer diameter larger than the outer diameter of the stepped portion 5a. That is, when the refill 6 is screwed to the one end 7a, the outer end of the one end 7a is located outside the outer end of the refill 6, so that when the cap 3 is attached, Is in contact with the end of the one end 7a so as to function as a so-called stopper.

The rear shaft 7 has a slightly tapered cylindrical outer shape from the one end 7a to the rear end 7c, and houses the ink tank 4 therein. It covers the entire circumference. The rear end 7c of the rear shaft 7 has a closed substantially hemispherical shape, and a substantially central portion of the rear end 7c has a ventilation hole 1 communicating the inside of the rear shaft 7 with the outside.
5 are formed.

The cap 3 is shown in FIGS.
As shown in (c), the cap body 20 and the crown 21 are configured to be detachable separately, and the inner cap 22 is disposed on the crown 21 side inside the cap body 20 and the crown 2.
A clip 23 is provided separately on one outer side. The cap body 20 is made of a colored opaque resin,
It has a substantially cylindrical shape, and has a front opening 20a at one end where the crown 21 is fitted, and a rear opening 20b at the other end where the stepped portion 5a of the front shaft 5 is fitted. Have been.

As shown in FIG. 2, a crown locking portion 20c for holding and fixing the crown 21 and an inner cap locking for preventing the inner cap 22 from dropping inside the front opening portion 20a. The shaft 20d is a first protruding portion for holding the pen tip side end 5b of the front shaft 5 to be fitted, which is continuously protruded inward along the circumferential direction. The locking portions 20e are provided in two rows along the circumferential direction, and are protruded inward at a plurality of locations in each row.

More specifically, the protrusion amount of the shaft locking portion 20e is such that the diameter D1 of a circle (virtual circle) circumscribing each protruding tip is slightly smaller than the outer diameter D2 of the rear end 7c. It is to be. In addition, the cap body 20
It goes without saying that even if it is distorted by the dimensional difference between the diameter D1 of the circle and the outer diameter D2 of the rear end portion 7c, it is not damaged. Further, the frictional force on the rear end surface caused by the reaction force of the distortion by the shaft locking portion 20e and the rear end portion 7c is set to be slightly larger than the spring force of the coil spring 26.

On the other hand, the inner diameter of the rear opening portion 20b is slightly smaller than the outer diameter of the stepped portion 5a, and is formed so that the cap 3 is attached to the writing instrument main body 2 so that the fitting is tight. .

The crown 21 is shown in FIGS.
As shown in (c), the tip portion 21a is made of a colored opaque resin, has a substantially hemispherical shape, is formed in a substantially shell shape, and the other end portion 21b is formed as an opening and is formed in a substantially cylindrical shape. Is formed to be hollow, and the inner cap 22 is installed. As shown in FIG. 3, the outer peripheral portion of the crown portion 21 is formed such that thick portions and thin portions having different thicknesses of the outer peripheral wall portion are alternately formed along the axial direction, Assuming that the thickness of the outer wall portion is t1, t2, t3,
It is assumed that t1> t2 and t3> t2.

The distal end portion 21a has a guide portion 21j which is a stroke restricting portion for restricting the amount of stroke of the inner cap 22 by guiding a part of the inner wall thereof rearward along the axial direction. Is formed. The other end 21b has a cylindrical outer diameter substantially the same as the inner diameter of the front opening 20a of the cap body 20, and the tip 21a is fitted into the front opening 20a of the cap body 20. In this state, the notch 21
n are formed continuously along the circumferential direction.

As shown in FIGS. 2 and 4 (a), the crown 21 has a clip 23 substantially at the center of the outer portion.
Is formed substantially parallel to the axial direction and flat. Above the mounting surface 21c, a stopper 21d for abutting the inner surface of the clip 23 to position the clip 23 is provided so as to project substantially parallel to the mounting surface 21c.

As shown in FIGS. 4A to 4C, the clip mounting portion 21e has guide grooves 21f which are narrowed in the width direction on the left and right sides of the rising portion from the mounting surface 21c. I have. In addition, as shown in FIGS. 4A to 4C, a ventilation hole 25 for communicating the inner space of the crown 21 with the outside is formed at a substantially central portion of the clip mounting portion 21e. I have. The ventilation hole 25 has a rectangular cross section that is long in the axial direction in plan view.

On the outer side of the crown 21, along the outer circumference of the mounting surface 21 c, the outer side of the crown 21 is recessed from the outer circumference.
Further, a concave portion 21h is formed at a lower part of the tip, the tip 21a being closer to the axis and becoming farther toward the other end 21b.

The clip 23 is made of metal and is formed by molding. As shown in FIG.
Is shorter than the entire length of the cap 3,
One end is a mounting portion 23a for mounting to the cap,
The other end is configured as an open end 23b.

The mounting portion 23a is shown in FIGS.
As shown in (c), the clip attaching portion 21e is covered, and the distal end of the clip attaching portion 21e is viewed from the side.
Is formed in a substantially L-shaped cross-sectional shape facing the side wall of.
The mounting portion 23a has a portion facing the clip mounting portion 21e formed in a substantially C-shaped cross section (a C-shaped opening downward) in a side view, and is formed by bending the holding portion 23c. Further, as shown in FIG. 4C, a portion behind the end of the clip attachment portion 21e is formed in a substantially U-shaped cross section (a U-shape opened downward) in a side view.

The clip 23 of the clip mounting portion 21e
4, a gap is formed between the clip attaching portion 21e and the attaching portion 23a to form an air passage 24, as shown in FIG.

The inner cap 22 is made of an opaque resin colored in the same color as the ink used for the writing implement, and has an outer diameter smaller than the inner diameter of the hollow portion of the crown 21 as shown in FIG. A space is created between the outer peripheral wall of the inner cap 22 and the inner peripheral wall of the crown 21 to form an air passage 27. The air passage 27 communicates with the outside of the cap 3 via the ventilation hole 25.

At one end of the inner cap 22,
A spring accommodating portion 22a into which a guide portion 21j of the crown portion 21 and a coil spring 26 described later are inserted is formed, and the coil spring 2 is inserted into the spring accommodating portion 22a.
On the other hand, a pen tip accommodating portion 22b for accommodating the pen tip portion 8 is formed at the other end, and the opening end 2
The pen tip 8a is prevented from contacting the inner wall of the inner cap 22 in a state where the pen tip 2c and a part of the outer periphery of the pen tip portion 8 are in contact with each other. At the bottom of the spring housing 22a,
A stopper portion 22f is protruded toward the opening side,
When the pen point portion 8 is accommodated in the cap 3, the stopper portion 22f and the guide portion 21j do not come into contact with each other.

A plurality of guide wings 22d are formed on the outer peripheral portion on the other end side along the circumferential direction, and the outer peripheral wall of the inner cap 22 is formed by using the inner peripheral wall of the cap body 20 as a guide. The inner cap 22 is slidably installed without contacting the inner peripheral wall of the cap body 20. In addition, a space between the adjacent guide blades 22d is used as an air passage 22e so that a space between the tip end side of the inner cap 22 and the cursive side can be communicated.

As shown in FIGS. 2 and 4C, the outer periphery of the guide portion 21j has a rib 21j-1 extending from the base 21j-2 to the tip 21j-3 along the axial direction. Radially protrudingly formed at four locations in a substantially cross shape in a circumferential cross-sectional shape. The tip 21j-3 has a tapered shape as shown in FIG. The tapered shape facilitates installation of the coil spring 26.

A stepped portion 21j-4 having a narrower tip portion 21j-3 is formed on the tip portion 21j-3 side from the axial center portion of the guide portion 21j.
6 are locked. The stepped portion 21j
Reference numeral -4 denotes a position where the inner cap 22 is pushed back by the urged coil spring 26, and is formed at a position inside the spring accommodating portion 22a from the end of the spring accommodating portion 22a of the inner cap 22. Thus, even when the inner cap 22 is pushed back by the coil spring 26, the coil spring 26 is not exposed from the spring accommodating portion 22a.

Here, the mounting of the writing instrument cap according to the present embodiment will be described. When the writing implement 1 is not used, the cap 3 is attached to the pen tip 8 of the writing implement 1 so that the pen tip 8 is not inadvertently stained while the pen tip 8 is exposed, and the pen tip is not dried. To At this time,
As shown in FIGS. 1A and 2, the cap 3 is mounted on the front shaft 5 with the rear opening 20 b in contact with one end 7 a of the rear shaft 7.
And the pen tip side end portion 5b is fitted to the shaft locking portion 20e and is mounted and held in the ink tank 4. The pen tip portion 8 in the cap 3 is arranged with the inner cap 22 pressed.

The inner cap 22 is attached to the crown 21
Of the coil spring 2 in a state where the guide portion 21j of the inner cap 22 does not contact the stopper portion 22f of the inner cap 22.
6 urges the pen tip 8. As a result, the opening-side end portion 22c comes into close contact with the pen tip portion 8, so that the pen tip can be stored in a closed state in the pen tip receiving portion 22b.

On the other hand, when the writing implement 1 is used, the cap 3 is removed from the tip of the writing implement main body 2 and attached to the rear end of the writing implement main body 2. At this time, the cap 3
As shown in FIGS. 1B and 3, the inner cap 22 is held by the rear end 7c of the rear shaft 7 by tight fitting by the inner cap locking portion 20d and the shaft locking portion 20e, and the inner cap 22 is pressed. It is attached in the state where it did.

The cap 3 includes an inner cap 22
Is pushed into the cap 3 while urging the coil spring 26 by the rear end portion 7c, and the stopper portion 22f is brought into contact with the guide portion 21j of the crown 21 so that the rear shaft 7 is mounted at a predetermined position on the rear end portion. Is done.

According to the present embodiment, the cap body 20 is formed of a transparent resin material, so that the inner cap 22 and the pen tip 8 disposed in the hollow portion of the cap body 20 are formed. Can be checked. Further, by forming the inner cap 22 from an opaque resin material having the same color as the ink used for the writing implement, the ink used can be identified, and the coil spring 26 provided inside the inner cap 22 can be identified. The appearance of the writing implement can be improved without showing the pen tip 8 or the like.

Further, the distal end portion 21j-3 of the guide portion 21j.
A thin stepped portion 21j-4 is formed on the side
1j-4 is formed at a position where the inner cap 22 is pushed back by the biased coil spring 26 and at a position inside the spring accommodating portion 22a of the inner cap 22 at the end of the spring accommodating portion 22a. When the writing instrument cap 3 is attached to the pen tip 8 side of the writing instrument body 2 during use, the spring accommodating section 22
a can be arranged in the spring accommodating portion 22a without being exposed from the
Can be arranged in the spring accommodating portion 22a without being exposed from the spring accommodating portion 22a in a state where the pen is removed from the pen tip portion 8 side of the writing implement main body 2. Thereby, the appearance of the writing implement 1 can be improved without showing the operation configuration of the coil spring 26 and the like.

The material of the cap body and the crown of the writing instrument cap 3 according to the present embodiment is made of acrylic, polycarbonate, polystyrene, AS resin, transparent ABS resin, transparent nylon, transparent polyolefin resin or the like. % Or more, or by coloring the transparent resin material, the components such as the cap body and the crown portion can be easily integrally molded by injection molding, so that cost reduction is achieved by mass production. be able to.

In this embodiment, the inner cap 2
2, the present invention is not limited to this. For example, a rubber material is interposed between the cap 3 and the inner cap 22 so that the elasticity of the rubber is improved. By inner cap 22
May be operated. In the case of such a configuration, it goes without saying that the size and shape of the guide portion are made to correspond to the elastic force of the rubber material.

In this embodiment, the guide portion 21j
The rib 21j-1 along the axial direction along the base 21j-2.
From the front end portion 21j-3 to the cross-sectional shape in the circumferential direction, four protruding portions are formed in a substantially cross shape. However, the present invention is not limited to this. A plurality of (for example, three) pins are protruded and formed at necessary portions from the base portion to the tip portion along the center direction to form a rib, and the pins guide the inner diameter portion of the spring. May be. According to this configuration, similar to the effect of the present embodiment, while reducing the material,
Outgassing (bubble prevention) during molding can be performed.
Further, the present invention is not limited to the above-described example, and various changes can be made without departing from the scope of the present invention.

[0044]

As described above, the first aspect of the present invention is as described above.
According to the writing instrument cap of any one of the above-described items 6, since the inner structure can be visually recognized by forming the crown portion from a material having visibility, it is possible to confirm the mounting state of the inner cap with the pen tip portion. . In addition, by changing the configuration of the crown portion so that the thick portion and the thin portion having different thicknesses of the outer peripheral wall portion are formed alternately, it is possible to reduce the material by reducing the thickness and to partially reduce the thickness. By making it thicker, it is possible to secure the strength at the required places. In addition, when a colored resin material is used, there is an excellent effect that a beautiful appearance having a change in color tone can be realized since a shade portion of the color is formed.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram showing an entire configuration of a writing instrument according to the embodiment of the present invention, and FIG. 1B is an explanatory diagram showing a configuration in a state in which the writing instrument is used.

FIG. 2 is a detailed cross-sectional view showing a configuration near the pen tip when the cap of the writing instrument is attached to the pen tip.

FIG. 3 is a detailed cross-sectional view showing a configuration of a rear end of the writing instrument with a cap attached to the rear end of the writing instrument.

4A is a side view showing a configuration of a crown portion of a cap of the writing instrument, FIG. 4B is a cross-sectional view of FIG.
(C) is a sectional view taken along the line BB of (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Writing implement 2 Writing implement main body 3 Writing implement cap 4 Ink tank 5 Front shaft 6 Refill 7 Rear shaft 8 Pen tip part 15 Vent hole 20 Cap main body 20e Shaft locking part 21 Crown part 21j Guide part 22 Inner cap 22a Spring accommodation part 22b Pen tip storage section 22f Stopper section 26 Coil spring

Claims (6)

[Claims] 1. A writing instrument cap provided separately from a writing instrument body, the cap body having a hollow portion formed therein and having an opening formed at one end; and the writing instrument being disposed inside the cap body. An inner cap for covering and protecting the pen tip at the tip of the main body, wherein the cap main body is provided with a crown portion formed with a guide portion for guiding the inner cap at a tip end side of a hollow portion thereof. In the writing instrument cap, the crown portion is formed of a material having visibility, and along the axial direction, a thick portion and a thin portion having different thicknesses of outer peripheral wall portions are formed. Characteristic writing instrument cap. 2. The inner cap is disposed movably in the axial direction via a coil spring at a distal end side inside the crown portion, and the inner cap is provided at one end along the axial direction. 2. The writing instrument cap according to claim 1, wherein a spring accommodating portion for accommodating the spring is provided, and a pen tip accommodating portion for covering the pen tip portion is formed at the other end. 3. The writing instrument cap according to claim 1, wherein a difference in wall thickness between a thick portion and a thin portion of an outer peripheral wall portion of the crown portion is twice or more. 4. The writing instrument cap according to claim 1, wherein the guide portion includes a rib formed along an axial direction. 5. The cap body and the crown are made of acrylic, polycarbonate, polystyrene, AS.
Resin, ABS resin, nylon, polyolefin resin,
The writing tool cap according to any one of claims 1 to 4, wherein the cap is made of a resin material having visibility including polyethylene terephthalate and the respective resin-based alloys. 6. The writing instrument cap according to claim 2, wherein a material of the inner cap is an opaque resin material.