JP7057124B2

JP7057124B2 - Stationery

Info

Publication number: JP7057124B2
Application number: JP2017246773A
Authority: JP
Inventors: 良昌菅原
Original assignee: Pilot Corp KK
Current assignee: Pilot Corp KK
Priority date: 2017-12-22
Filing date: 2017-12-22
Publication date: 2022-04-19
Anticipated expiration: 2037-12-22
Also published as: JP2019111722A

Description

本発明は、軸筒に対して尾栓を装着した筆記具に関するものである。 The present invention relates to a writing instrument in which a breech plug is attached to a barrel.

従来からキャップ式の筆記具などでは軸筒後端に尾栓を装着する筆記具はよく知られており、例えば特許文献１には、軸筒の後端開口部に尾栓を圧入して嵌着することで軸筒に対して尾栓を装着している筆記具が開示されている。
この特許文献１の尾栓取り付け構造では、軸筒と尾栓との嵌合力は軸筒の内径寸法および尾栓の外径寸法に依存しているため、装着時の嵌合力にはバラツキが発生し易く、必要に応じて接着剤等を併用して固着する必要があった。 Conventionally, writing tools that attach a breech plug to the rear end of the shaft tube are well known in cap-type writing tools and the like. For example, in Patent Document 1, the tail plug is press-fitted into the rear end opening of the shaft tube. As a result, a writing tool with a breech plug attached to the barrel is disclosed.
In the breech plug mounting structure of Patent Document 1, the fitting force between the breech plug and the breech plug depends on the inner diameter dimension of the breech plug and the outer diameter dimension of the breech plug, so that the fitting force at the time of mounting varies. It was easy to do, and it was necessary to use an adhesive or the like in combination to fix it as needed.

一方、特許文献２には、軸筒の開口部にクリップを一体成形した部材（以降クリップ部材）を装着する構造が開示されている。
この特許文献２の構造では、クリップ部材が、外方へ露出する外筒部と、軸筒の開口部内に挿入される内筒部とを有し、内筒部の外周面に係合突起とガイド用突起が形成され、軸筒の開口部の内壁面に軸方向に延びるガイド溝と係合孔とが形成され、クリップ部材の内筒部のガイド用突起を軸筒のガイド溝に挿嵌しつつクリップ部材の内筒部を軸筒内に挿入し、軸筒の係合孔とクリップ部材の係合突起とを係合させることで、軸筒に対してクリップ部材を装着している。このため、クリップ部材は軸筒に対して回転方向を決められた状態で係合される。 On the other hand, Patent Document 2 discloses a structure in which a member (hereinafter referred to as a clip member) in which a clip is integrally molded is attached to an opening of a shaft cylinder.
In the structure of Patent Document 2, the clip member has an outer cylinder portion exposed to the outside and an inner cylinder portion inserted into the opening of the shaft cylinder, and has an engaging protrusion on the outer peripheral surface of the inner cylinder portion. A guide protrusion is formed, a guide groove extending in the axial direction and an engagement hole are formed on the inner wall surface of the opening of the shaft cylinder, and the guide protrusion of the inner cylinder portion of the clip member is inserted into the guide groove of the shaft cylinder. The clip member is attached to the shaft cylinder by inserting the inner cylinder portion of the clip member into the shaft cylinder and engaging the engaging hole of the shaft cylinder with the engaging protrusion of the clip member. Therefore, the clip member is engaged with the shaft cylinder in a state in which the rotation direction is determined.

しかしながら、特許文献２の構造では、係合突起を係合孔に入れるために、軸筒の開口端から係合孔の距離に比べて、クリップ部材の内筒部の端部から係合突起までの距離を大きく形成する必要がある。このため、その差分が係合時における軸方向でのガタツキになることで、係合後も軸筒に対してクリップ部材が前後に動いてしまう問題があった。 However, in the structure of Patent Document 2, in order to insert the engaging protrusion into the engaging hole, the distance from the end of the inner cylinder portion of the clip member to the engaging protrusion is compared with the distance from the opening end of the shaft tube to the engaging hole. It is necessary to form a large distance. For this reason, there is a problem that the clip member moves back and forth with respect to the shaft cylinder even after the engagement because the difference becomes rattling in the axial direction at the time of engagement.

また、特許文献３には、キャップを軸筒に装着した際に該キャップと軸筒との軸方向におけるガタツキを防止する構造が開示されている。
この特許文献３の構造では、軸筒の外周面に環状の外向突起が一体に形成され、キャップを構成する外筒部の内周面には環状の内向突起が形成され、外向突起の後面が後方へ向かうに従って外径が小さくなる傾斜面状に形成されている。このため、キャップを軸筒に装着し、外向突起に内向突起が乗り越え係合された状態では、内向突起が外向突起後面により後方へ押圧された状態になり、キャップのガタツキを防止することができる。 Further, Patent Document 3 discloses a structure for preventing rattling of the cap and the shaft cylinder in the axial direction when the cap is attached to the shaft cylinder.
In the structure of Patent Document 3, an annular outward protrusion is integrally formed on the outer peripheral surface of the shaft cylinder, an annular inward protrusion is formed on the inner peripheral surface of the outer cylinder portion constituting the cap, and the rear surface of the outward protrusion is formed. It is formed in an inclined surface shape in which the outer diameter decreases toward the rear. Therefore, when the cap is attached to the axle tube and the introvert is engaged with the outward protrusion, the inward protrusion is pressed backward by the rear surface of the outward protrusion, and rattling of the cap can be prevented. ..

実公昭５６－３１４１１号公報Jikkensho 56-31411 Gazette 特開平１１－１８００８７号公報Japanese Unexamined Patent Publication No. 11-18807 特開２００５－０４１２０１号公報Japanese Unexamined Patent Publication No. 2005-041201

しかしながら、特許文献３の構造は、キャップ装着時のガタツキを防止することができるが、外向突起の後面を傾斜面状に形成しているため、外向突起と内向突起との係合状態が外れやすく、取り外し自在なキャップと軸筒との係合などには効果を発揮するが、軸筒に対して着脱不能に尾栓を装着する場合には尾栓が外れ易くなる問題がある。 However, although the structure of Patent Document 3 can prevent rattling when the cap is attached, since the rear surface of the outward protrusion is formed in an inclined surface shape, the engagement state between the outward protrusion and the inward protrusion is likely to be disengaged. Although it is effective for engaging the removable cap with the shaft cylinder, there is a problem that the tail plug is easily removed when the tail plug is attached to the shaft cylinder so as not to be removable.

本発明は、前記問題を鑑みてなされたものであって、軸筒に尾栓を装着する際に、ガタツキを防止した状態で装着でき、且つ、尾栓を軸筒から外れ難く構成した筆記具を提供することを目的とした。 INDUSTRIAL APPLICABILITY The present invention has been made in view of the above problems, and is a writing tool having a structure in which a breech plug can be mounted in a state of preventing rattling when the breech plug is mounted on the barrel, and the breech plug cannot be easily removed from the barrel. The purpose was to provide.

本発明は、
「１．後端部に開口部を備えた軸筒と、前記開口部に装着される尾栓と、を備えた筆記具であって、
前記尾栓が、後端に有底部を備えた筒状に形成されると共に、前記軸筒の後端部に当接する鍔部と、前記軸筒の内壁に設けた被係止部に係止する係止部と、を具備し、
前記係止部の後端に、軸方向に対して傾斜した方向に延びる後方当接部と、後方当接部の前端に連接し外方へ向って突設された後方壁部と、を備え、
前記被係止部の前端に、前記係止部の後方当接部と当接する被当接部と、前記尾栓が前記軸筒に対して後退した際、前記係止部の後方壁部に係合するよう該後方壁部の形状に合わせて形成された前方壁部と、を備え、
前記尾栓の後方壁部に、軸方向後方に向って突出する凸部、または、軸方向前方へ向かって凹む凹部が形成され、
前記軸筒の前方壁部に、軸方向後方へ向って凹み前記後方壁部の凸部と係合する凹状部、または、軸方向前方へ向って突出し前記後方壁部の凹部と係合する凸状部が形成されたことを特徴としたことを特徴とする筆記具。
２．後端部に開口部を備えた軸筒と、前記開口部に装着される尾栓と、を備えた筆記具であって、
前記尾栓が、後端に有底部を備えた筒状に形成されると共に、前記軸筒の後端部に当接する鍔部と、前記軸筒の内壁に設けた被係止部に係止する係止部と、外周部に外方へ向って突出すると共に軸方向に沿って延びるよう形成されたガイド部と、を具備し、
前記係止部の後端に、軸方向に対して傾斜した方向に延びる後方当接部と、後方当接部の前端に連接し外方へ向って突設された後方壁部と、を備え、
前記被係止部の前端に、前記係止部の後方当接部と当接する被当接部と、前記尾栓が前記軸筒に対して後退した際、前記係止部の後方壁部に係合するよう該後方壁部の形状に合わせて形成された前方壁部と、を備え、
前記ガイド部が、軸方向に分断されていることを特徴とする筆記具。
３．前記尾栓の後方当接部と前記軸筒の被当接部とが当接した状態では、前記軸筒の前方壁部と前記尾栓の後方壁部との間に形成される隙間が０．０４ｍｍ以上、０．２０ｍｍ以下となることを特徴とする前記１項または２項に記載の筆記具。」である。

The present invention
"1. A writing instrument provided with a shaft tube having an opening at the rear end and a breech plug attached to the opening.
The breech plug is formed in a tubular shape having a bottomed portion at the rear end, and is locked to a flange portion that abuts on the rear end portion of the shaft cylinder and a locked portion provided on the inner wall of the shaft cylinder. With a locking part,
The rear end of the locking portion is provided with a rear contact portion extending in a direction inclined with respect to the axial direction, and a rear wall portion connected to the front end of the rear contact portion and projecting outward. ,
At the front end of the locked portion, the contacted portion that comes into contact with the rear contact portion of the locked portion and the rear wall portion of the locked portion when the tail plug retracts with respect to the barrel. A front wall portion formed to match the shape of the rear wall portion so as to be engaged is provided.
The rear wall portion of the breech plug is formed with a convex portion that protrudes rearward in the axial direction or a concave portion that is recessed toward the front in the axial direction.
A concave portion that dents backward in the axial direction and engages with the convex portion of the rear wall portion, or a convex portion that protrudes forward in the axial direction and engages with the concave portion of the rear wall portion. A writing tool characterized in that a shaped part is formed .
2. 2. A writing instrument provided with a shaft tube having an opening at the rear end and a breech plug attached to the opening.
The breech plug is formed in a tubular shape having a bottomed portion at the rear end, and is locked to a flange portion that abuts on the rear end portion of the shaft cylinder and a locked portion provided on the inner wall of the shaft cylinder. It is provided with a locking portion for locking and a guide portion formed so as to project outward and extend along the axial direction on the outer peripheral portion.
The rear end of the locking portion is provided with a rear contact portion extending in a direction inclined with respect to the axial direction, and a rear wall portion connected to the front end of the rear contact portion and projecting outward. ,
At the front end of the locked portion, the contacted portion that comes into contact with the rear contact portion of the locked portion and the rear wall portion of the locked portion when the tail plug retracts with respect to the barrel. A front wall portion formed to match the shape of the rear wall portion so as to be engaged is provided.
A writing tool characterized in that the guide portion is divided in the axial direction.
3. 3. In a state where the rear contact portion of the breech plug and the contacted portion of the breech plug are in contact with each other, the gap formed between the front wall portion of the breech plug and the rear wall portion of the breech plug is 0. The writing tool according to item 1 or 2, wherein the size is .04 mm or more and 0.20 mm or less. ".

本発明によれば、尾栓の係止部の後端に、軸方向に対して傾斜した方向に延びる後方当接部を形成し、軸筒内壁に形成した被係止部の前端に尾栓の後方当接部と当接する被当接部を形成することで、軸筒に対して尾栓が常に前方側に付勢される。このため、尾栓の鍔部が軸筒の後端に常に当接することで、尾栓が軸筒に対して軸方向にガタツクことを防止できる。また、尾栓が軸筒に対して後退した際、後方当接部の前端に連接して突設された後方壁部に係合するよう該後方壁部の形状に合わせて前方壁部を形成することで、軸筒に対して無理に尾栓を引き抜こうとしても、係止部の後方壁部と被係止部の前方壁部とが係合することで尾栓が軸筒から抜けてしまうことを防止することができる。 According to the present invention, a rear contact portion extending in a direction inclined with respect to the axial direction is formed at the rear end of the locking portion of the breech plug, and the breech plug is formed at the front end of the locked portion formed on the inner wall of the barrel. By forming the contacted portion that comes into contact with the rear contact portion of the breech plug, the breech plug is always urged to the front side with respect to the barrel. Therefore, since the flange portion of the breech plug always abuts on the rear end of the barrel, it is possible to prevent the breech plug from rattling in the axial direction with respect to the barrel. Further, when the breech plug retracts with respect to the barrel, the front wall portion is formed according to the shape of the rear wall portion so as to engage with the rear wall portion that is connected to the front end of the rear contact portion and is projected. By doing so, even if the tail plug is forcibly pulled out from the barrel, the tail plug will come out of the barrel due to the engagement between the rear wall portion of the locking portion and the front wall portion of the locked portion. It is possible to prevent it from being stored.

また、尾栓の後方壁部に、軸方向後方に向って突出する凸部、または、軸方向前方へ向かって凹む凹部を形成し、軸筒の前方壁部に、軸方向後方へ向って凹み後方壁部の凸部と係合する凹状部、または、軸方向前方へ向って突出し後方壁部の凹部と係合する凸状部を形成することが好ましく、この場合、軸筒に対して無理に尾栓を引き抜こうとして、係止部の後方壁部と被係止部の前方壁部とが当接すると、後方壁部の凸部または凹部が、前方壁部の凹状部または凸状部と係合することで、係止部と被係止部とがより強固に係合することとなり、軸筒から尾栓が抜けることを防止する効果を高めることができる。 Further, the rear wall portion of the tail plug is formed with a convex portion protruding toward the rear in the axial direction or a concave portion recessed toward the front in the axial direction, and the front wall portion of the barrel is recessed toward the rear in the axial direction. It is preferable to form a concave portion that engages with the convex portion of the rear wall portion, or a convex portion that protrudes forward in the axial direction and engages with the concave portion of the rear wall portion. When the rear wall portion of the locking portion and the front wall portion of the locked portion come into contact with each other in an attempt to pull out the tail plug, the convex or concave portion of the rear wall portion becomes the concave or convex portion of the front wall portion. By engaging with, the locked portion and the locked portion are engaged more firmly, and the effect of preventing the tail plug from coming off from the barrel can be enhanced.

更に、尾栓の後方当接部と軸筒の被当接部とが当接した状態では、軸筒の前方壁部と尾栓の後方壁部との間に形成される隙間が０．０４ｍｍ以上、０．２０ｍｍ以下となるよう構成することが好ましく、この場合、隙間が０．０４ｍｍ以上あることで、係止部と被係止部とを余裕を持って係合させことができ、且つ、隙間が０．２０ｍｍ以下とすることで、尾栓を無理に抜こうとしてもすぐに後方壁部と前方壁部とが当接することで勢いが付かず、尾栓の抜けを防止することができる。 Further, when the rear contact portion of the breech plug and the contacted portion of the breech plug are in contact with each other, the gap formed between the front wall portion of the breech plug and the rear wall portion of the breech plug is 0.04 mm. As described above, it is preferable to configure the structure so as to be 0.20 mm or less. In this case, when the gap is 0.04 mm or more, the locked portion and the locked portion can be engaged with each other with a margin. By setting the gap to 0.20 mm or less, even if you try to forcibly pull out the breech plug, the rear wall part and the front wall part will immediately come into contact with each other, which will not give momentum and prevent the breech plug from coming off. can.

本発明により、軸筒に尾栓を装着する際に、ガタツキを防止した状態で装着でき、更に、尾栓が軸筒から外れ難く構成した筆記具を提供することができた。 INDUSTRIAL APPLICABILITY According to the present invention, when the breech plug is attached to the barrel, it can be attached in a state where rattling is prevented, and further, it is possible to provide a writing tool having a structure in which the breech plug does not easily come off from the barrel.

実施例１の筆記具（ボールペン）の縦断面図である。It is a vertical sectional view of the writing tool (ballpoint pen) of Example 1. FIG. 図１の筆記具の要部を拡大した要部拡大縦断面図である。It is an enlarged vertical sectional view of the main part of the writing tool of FIG. 図２におけるＡ－Ａ断面図である。FIG. 2 is a cross-sectional view taken along the line AA in FIG. 実施例１における尾栓の斜視図である。It is a perspective view of the breech plug in Example 1. FIG. 軸筒に尾栓を取り付ける状況を説明するための説明図である。It is explanatory drawing for demonstrating the situation which attaches the breech plug to a shaft cylinder. 図１において、軸筒に対して尾栓が後方へ移動した状態の要部拡大断面図である。FIG. 1 is an enlarged cross-sectional view of a main part in a state where the breech plug is moved rearward with respect to the barrel. 図６の要部を更に拡大した要部拡大断面図である。6 is an enlarged cross-sectional view of a main part of FIG. 6 which is a further enlarged view of the main part. 実施例２の筆記具の要部を拡大した要部拡大縦断面図である。FIG. 3 is an enlarged vertical cross-sectional view of a main part of the writing tool of the second embodiment in an enlarged manner. 図８において、軸筒に対して尾栓が後方へ移動した状態の要部拡大断面図である。FIG. 8 is an enlarged cross-sectional view of a main part in a state where the breech plug is moved rearward with respect to the barrel. 図９の要部を更に拡大した要部拡大断面図である。9 is an enlarged cross-sectional view of a main part of FIG. 9 which is a further enlarged view of the main part.

次に図面を参照しながら、本発明の筆記具をボールペンを用いて詳細に説明するが、本発明は以下の実施例に限定されるものではない。
また、本実施例では、軸筒の長手方向において、ボールペンチップがある方を前方と表現し、その反対側を後方と表現する。更に、軸筒の軸径方向において、ボールペンレフィルがある方を内方と表現し、その反対側を外方と表現する。
尚、説明を分かりやすくするために、図面中の同様の部材、同様の部分については同じ符号を付してある。 Next, the writing tool of the present invention will be described in detail using a ballpoint pen with reference to the drawings, but the present invention is not limited to the following examples.
Further, in this embodiment, in the longitudinal direction of the barrel, the side with the ballpoint pen tip is expressed as the front, and the opposite side is expressed as the rear. Further, in the axial direction of the shaft cylinder, the side with the ballpoint pen refill is expressed as the inner side, and the opposite side is expressed as the outer side.
In addition, in order to make the explanation easy to understand, the same members and the same parts in the drawings are designated by the same reference numerals.

実施例１
本発明の筆記具１（ボールペン）は、図１から図７に示すように、筒状に形成した後軸２の前部に同じく筒状に形成した前軸３を螺合することで固定し、更に、前軸３の前部に筒状の先口４を螺合することで固定してある。また、筆記具１は、後軸２と前軸３と先口４とで軸筒５を形成してあり、先口４の前端開口部から筆記先端部７ａが突出するようにボールペンレフィル７を軸筒５内に収納し、後軸２（軸筒５）の後端に尾栓６を装着してある。更に、ボールペンレフィル７と先口の内段との間に、弱い弾発力で形成したコイルスプリング１１が配設してあり、コイルスプリング１１によりボールペンレフィル７を後方へ弾発してある。 Example 1
As shown in FIGS. 1 to 7, the writing tool 1 (ballpoint pen) of the present invention is fixed by screwing the front shaft 3 also formed into a cylinder to the front portion of the rear shaft 2 formed into a cylinder. Further, the tubular tip opening 4 is fixed to the front portion of the front shaft 3 by screwing it. Further, in the writing tool 1, a shaft cylinder 5 is formed by a rear shaft 2, a front shaft 3, and a front opening 4, and a ballpoint pen refill 7 is shafted so that the writing tip portion 7a protrudes from the front end opening of the front opening 4. It is housed in the cylinder 5, and the tail plug 6 is attached to the rear end of the rear shaft 2 (shaft cylinder 5). Further, a coil spring 11 formed by a weak elastic force is arranged between the ballpoint pen refill 7 and the inner stage of the tip, and the ballpoint pen refill 7 is repelled backward by the coil spring 11.

ボールペンレフィル７は、図１に示すように、先端開口部にタングステンカーバイド製のボールを抱持させ、筆記先端部７ａとなるボールペンチップ８を、樹脂製のインキ収容筒９の前端部に、チップホルダー１０を介して装着してある。
このボールペンレフィル７で筆記すると、ボールペンチップ８のボールの回転と筆圧によって、ボールがボールペンチップ８の先端開口部の底壁側に移動して、先端開口部の内壁とボールに隙間を生じ、インキ収容筒９内に収納した筆記具用水性ゲルインキを吐出して筆記することができる。 As shown in FIG. 1, the ballpoint pen refill 7 has a tungsten carbide ball held in the tip opening, and a ballpoint pen tip 8 serving as a writing tip 7a is attached to the front end of the resin ink storage cylinder 9. It is attached via the holder 10.
When writing with this ballpoint pen refill 7, the ball moves to the bottom wall side of the tip opening of the ballpoint pen tip 8 due to the rotation and pressure of the ball of the ballpoint pen tip 8, creating a gap between the inner wall of the tip opening and the ball. The water-based gel ink for writing tools stored in the ink storage cylinder 9 can be ejected for writing.

前軸３は、図１に示すように、筒状に形成してあり、前端内周部に先口４の雄螺子部４ａと螺合するための前部雌螺子部３ａを形成してあり、後部外周部には後部雄螺子部３ｂを形成してある。 As shown in FIG. 1, the front shaft 3 is formed in a cylindrical shape, and a front female screw portion 3a for screwing with the male screw portion 4a of the front opening 4 is formed on the inner peripheral portion of the front end. A rear male screw portion 3b is formed on the outer peripheral portion of the rear portion.

後軸２は、図１から図３及び図５に示すように、筒状に形成してあり、前端内周部に前軸３の後部雄螺子部３ａと螺合するための雌螺子部２ａを形成してあり、後部内周部２ｂ（開口部）には、軸周方向に均等配置させた状態で形成した複数のリブ２ｃと、内方へ向って突出し軸周方向に延びる内突起２ｄ（被係止部）と、を形成してある。そして、隣り合うリブ２ｃの間には内溝部２ｅが形成される。
尚、内突起２ｄ（被係止部）の前端には、図２及び図５に示すように、軸方向に対して直交する方向に延びる前方壁部２ｆと、前方壁部２ｆの内方端には先端角部２ｇ（被当接部）と、が形成してある。また、リブ２ｃの後端の内周部は拡径された内側部２ｈが形成してある。 As shown in FIGS. 1 to 3 and 5, the rear shaft 2 is formed in a cylindrical shape, and the female screw portion 2a for screwing the rear male screw portion 3a of the front shaft 3 to the inner peripheral portion of the front end. In the rear inner peripheral portion 2b (opening), a plurality of ribs 2c formed in a state of being evenly arranged in the axial circumferential direction, and an internal protrusion 2d protruding inward and extending in the axial circumferential direction. (Locked portion) and. Then, an inner groove portion 2e is formed between the adjacent ribs 2c.
As shown in FIGS. 2 and 5, the front end of the internal protrusion 2d (locked portion) has a front wall portion 2f extending in a direction orthogonal to the axial direction and an inner end of the front wall portion 2f. The tip corner portion 2 g (contacted portion) is formed in the. Further, the inner peripheral portion of the rear end of the rib 2c is formed with an enlarged inner peripheral portion 2h.

尾栓６は、図２から図５に示すように、内孔６ａに有底部６ｂを備えた筒状に形成してあり、後軸２内（軸筒５内）に挿入される内筒部６ｃと後軸２の後端面２ｉに当接する鍔部６ｄを備えた後筒部６ｅとで構成してある。また、内筒部６ｃの前部は太径に形成してあり、前端にはボールペンレフィル７の後端部が当接して、ボールペンレフィル７の後退を制限してある。更に、内筒部６ｃの外周面には、内外を貫通し、軸方向に延びるよう楕円形状で形成した切欠部６ｆと、切欠部６ｆに対して９０°回転した位置に、外方へ向って突出し、軸心を挟んで対称に２箇所形成した係止突起６ｇ（係止部）と、当該係止突起６ｇ（係止部）の後方に、外方へ向って突出し軸方向に延びるレール状に形成された第一ガイド部６ｈと、軸周方向に延びるように形成された第二ガイド部６ｉと、を設けてある。 As shown in FIGS. 2 to 5, the breech plug 6 is formed in a tubular shape having a bottomed portion 6b in the inner hole 6a, and the inner cylinder portion inserted into the rear shaft 2 (inside the shaft cylinder 5). It is composed of 6c and a rear cylinder portion 6e provided with a flange portion 6d that abuts on the rear end surface 2i of the rear shaft 2. Further, the front portion of the inner cylinder portion 6c is formed to have a large diameter, and the rear end portion of the ballpoint pen refill 7 abuts on the front end to limit the retreat of the ballpoint pen refill 7. Further, on the outer peripheral surface of the inner cylinder portion 6c, a notch portion 6f formed in an elliptical shape so as to penetrate inside and outside and extend in the axial direction, and a position rotated by 90 ° with respect to the notch portion 6f toward the outside. A rail shape that protrudes outward and extends in the axial direction behind the locking projection 6g (locking portion) that protrudes and is symmetrically formed at two locations with the axial center in between, and the locking projection 6g (locking portion). A first guide portion 6h formed in the above and a second guide portion 6i formed so as to extend in the axial direction are provided.

尾栓６を更に詳述すると、尾栓６の第一ガイド部６ｈは、軸周方向に延びるように形成され溝状に形成された第一溝部６ｊにより軸方向に対して前後に分断され、前部第一ガイド部６ｈ１と後部第一ガイド部６ｈ２が形成される。また、第二ガイド部６ｉは、軸周方向に延びるように形成され溝状に形成された第二溝部６ｋにより軸方向に対して前後に分断され、前部第二ガイド部６ｉ１と後部第二ガイド部６ｉ２が形成される。そして、第一溝部６ｊと第二溝部６ｋは連接するように形成され、一体の溝部として形成してある。
また、切欠部６ｆの後端は第二溝部６ｋまで達しており、前部第二ガイド部６ｉ１は、切欠部６ｆにより軸周方向にも分断されるよう構成してある。また、前部第一ガイド部６ｈ１の前端は尖形状に形成してある。
尚、具体的には、第一溝部６ｊの幅は１．０ｍｍで形成し、第二溝部６ｋの幅を１．６ｍｍで形成した。 More specifically, the first guide portion 6h of the tail plug 6 is divided back and forth with respect to the axial direction by the first groove portion 6j formed so as to extend in the axial direction and formed in a groove shape. The front first guide portion 6h1 and the rear first guide portion 6h2 are formed. Further, the second guide portion 6i is divided in the front-rear direction with respect to the axial direction by the second groove portion 6k formed so as to extend in the axial direction, and the front second guide portion 6i1 and the rear second guide portion 6i. The guide portion 6i2 is formed. The first groove portion 6j and the second groove portion 6k are formed so as to be connected to each other, and are formed as an integral groove portion.
Further, the rear end of the notch portion 6f reaches the second groove portion 6k, and the front second guide portion 6i1 is configured to be divided in the axial circumferential direction by the notch portion 6f. Further, the front end of the front first guide portion 6h1 is formed in a pointed shape.
Specifically, the width of the first groove portion 6j was formed to be 1.0 mm, and the width of the second groove portion 6k was formed to be 1.6 mm.

また、尾栓６の係止突起６ｇ（係止部）の後端には、軸方向に対して傾斜した後方傾斜部６ｍ（後方当接部）と、後方傾斜部６ｍ（後方当接部）の前端に連接し外方へ向って突設された後方壁部６ｎと、が形成されており、尾栓６の後方傾斜部６ｍ（後方当接部）と、後軸２の内突起２ｄ（被係止部）の先端角部２ｇ（被当接部）と、が当接した状態で係合させてある。
尚、尾栓６の後方傾斜部６ｍ（後方当接部）と、後軸２の内突起２ｄ（被係止部）の先端角部２ｇ（被当接部）と、が当接した状態では、後軸２（軸筒５）の前方壁部２ｆと尾栓６の後方壁部６ｎとの間には隙間が形成され、その隙間は、０．０４ｍｍ以上、０．２０ｍｍ以下となるよう構成することが好ましく、隙間を０．０４ｍｍ以上とすることで、係止突起６ｇ（係止部）と内突起２ｄ（被係止部）とを余裕を持って係合させことができ、且つ、隙間を０．２０ｍｍ以下とすることで、尾栓６が後退可能な距離が制限され、尾栓６が後軸２（軸筒５）に対して抜け難くなる効果を奏する。 Further, at the rear end of the locking projection 6g (locking portion) of the breech plug 6, a rear inclined portion 6 m (rear contact portion) inclined with respect to the axial direction and a rear inclined portion 6 m (rear contact portion) are provided. The rear wall portion 6n which is connected to the front end of the breech plug 6 and protrudes outward is formed, and the rear inclined portion 6m (rear contact portion) of the breech plug 6 and the internal protrusion 2d of the rear shaft 2 ( It is engaged with the tip corner portion 2g (contacted portion) of the locked portion) in an abutted state.
In a state where the rear inclined portion 6 m (rear contact portion) of the tail plug 6 and the tip corner portion 2 g (contact contact portion) of the internal protrusion 2d (locked portion) of the rear shaft 2 are in contact with each other. , A gap is formed between the front wall portion 2f of the rear shaft 2 (axle cylinder 5) and the rear wall portion 6n of the tail plug 6, and the gap is configured to be 0.04 mm or more and 0.20 mm or less. By setting the gap to 0.04 mm or more, the locking protrusion 6g (locking portion) and the inner protrusion 2d (locked portion) can be engaged with each other with a margin. By setting the gap to 0.20 mm or less, the distance that the breech plug 6 can retract is limited, and the breech plug 6 has an effect of being difficult to come off with respect to the rear shaft 2 (axle cylinder 5).

ここで、尾栓６を後軸２（軸筒５）に取り付ける際の状態を説明する。
図５に示すように、尾栓６の内筒部６ｃを前方にした状態で、後軸２の後部内周部２ｂに内筒部６ｃを挿入すると、尾栓６の係止突起６ｇ（係止部）が後軸２の内突起２ｄと当接するより先に、尾栓６の前部第一ガイド部６ｈ１の尖形状に形成した前端が後軸２の内溝部２ｅに挿入され、前部第一ガイド部６ｈ１により尾栓６の軸周方向の位置が案内される。そして、後軸２の内側部２ｈまで尾栓６の前部第二ガイド部６ｉ１が進むと、内側部２ｈに前部第二ガイド部６ｉ１が挿入され、後軸２に対して尾栓６の軸径方向の位置が案内される。更に、尾栓６を前方へ押し込むと、尾栓６の係止突起６ｇ（係止部）が後軸２の内突起２ｄに対して乗り越え嵌合する。この際、尾栓６の第一ガイド部６ｈは第一溝部６ｊにより軸方向に対して前後に分断され、第二ガイド部６ｉは第二溝部６ｋにより軸方向に対して前後に分断されると共に、第一ガイド部６ｈの前部第一ガイド部６ｈ１が、切欠部６ｆにより軸周方向に対して分断されていることから、乗り越え嵌合時に係止突起６ｇ（係止部）が内突起２ｄ（被係止部）により内方側に押圧されると、内筒部６ｃは内方側へ撓み易くなるよう構成してある。このため、後軸２（軸筒５）に対して尾栓６を容易に装着することができた。 Here, a state when the tail plug 6 is attached to the rear shaft 2 (axle cylinder 5) will be described.
As shown in FIG. 5, when the inner cylinder portion 6c is inserted into the rear inner peripheral portion 2b of the rear shaft 2 with the inner cylinder portion 6c of the tail plug 6 facing forward, the locking projection 6g (engagement) of the tail plug 6 is inserted. The front end formed in a pointed shape of the front first guide portion 6h1 of the breech plug 6 is inserted into the inner groove portion 2e of the rear shaft 2 before the stop portion) comes into contact with the internal protrusion 2d of the rear shaft 2. The position of the tail plug 6 in the axial circumferential direction is guided by the first guide portion 6h1. Then, when the front second guide portion 6i1 of the tail plug 6 advances to the inner portion 2h of the rear shaft 2, the front second guide portion 6i1 is inserted into the inner portion 2h, and the tail plug 6 is inserted with respect to the rear shaft 2. The position in the axial direction of the shaft is guided. Further, when the tail plug 6 is pushed forward, the locking projection 6g (locking portion) of the tail plug 6 gets over and fits with the internal projection 2d of the rear shaft 2. At this time, the first guide portion 6h of the tail plug 6 is divided back and forth in the axial direction by the first groove portion 6j, and the second guide portion 6i is divided back and forth in the axial direction by the second groove portion 6k. Since the front first guide portion 6h1 of the first guide portion 6h is divided in the axial circumferential direction by the notch portion 6f, the locking projection 6g (locking portion) becomes the internal projection 2d at the time of overcoming fitting. When pressed inward by the (locked portion), the inner cylinder portion 6c is configured to easily bend inward. Therefore, the breech plug 6 could be easily attached to the rear shaft 2 (axle cylinder 5).

また、具体的には、尾栓６を装着する際に必要となった押圧力は１９．６Ｎであり、第一溝部６ｊ及び第二溝部６ｋの幅を０．５ｍｍ以上としていることで尾栓６の装着時の押圧力を抑えることができた。更に、第一溝部及び第二溝部の幅を２．０ｍｍ以下としていることで、後部第一ガイド部６ｈ２及び後部第二ガイド部６ｉ２が後軸２の内溝部２ｅ及び内側部２ｈに挿入される際、尾栓６は後軸２（軸筒５）に対して傾くことはなく、スムーズに挿入された。
更に、尾栓６を後軸２に装着した際、尾栓６の係止突起６ｇ（係止部）の後方壁部６ｎと後軸２（軸筒５）の内突起２ｄ（被係止部）の前方壁部２ｆとの間の隙間の幅は０．１０ｍｍであり、隙間の幅が０．０４ｍｍ以上あるため、尾栓６の装着時の係止突起６ｇ（係止部）が内突起２ｄ（被係止部）に対して乗り越え嵌合する際に、内突起２ｄ（被係止部）が係止突起６ｇ（係止部）に接触して微小に傾いても、乗り越えることができた。

Specifically, the pressing force required when mounting the breech plug 6 is 19.6 N, and the width of the first groove portion 6j and the second groove portion 6k is 0.5 mm or more, so that the breech plug is used. It was possible to suppress the pressing force at the time of mounting 6. Further, by setting the width of the first groove portion and the second groove portion to 2.0 mm or less, the rear first guide portion 6h2 and the rear second guide portion 6i2 are inserted into the inner groove portion 2e and the inner groove portion 2h of the rear shaft 2. At that time, the breech plug 6 was not tilted with respect to the rear shaft 2 (shaft cylinder 5) and was smoothly inserted.
Further, when the tail plug 6 is attached to the rear shaft 2, the rear wall portion 6n of the locking projection 6g (locking portion) of the tail plug 6 and the internal projection 2d (locked portion) of the rear shaft 2 (shaft cylinder 5) are further mounted. The width of the gap between the front wall portion 2f and the front wall portion 2f is 0.10 mm, and the width of the gap is 0.04 mm or more. Even if the internal protrusion 2d (locked portion) comes into contact with the locking protrusion 6g (locking portion) and tilts slightly when fitting over the 2d (locked portion), the internal protrusion 2d (locked portion) can be overcome. Was done.

尚、本実施例では、後軸２の内溝部２ｅが隣り合うリブ２ｃ同士の間に複数形成されると共に、内溝部２ｅの後端部は傾斜して形成することで拡口されており、同時に、尾栓６の前部第一ガイド部６ｈ１の前端部も尖形状に形成してあるため、尾栓６を後軸２に挿入する際、軸周方向の回転位置を合わせることなく挿入しても、第一ガイド部６ｈが内溝部２ｅに案内されて軸周方向の嵌合位置が合うように構成してある。このため、後軸２（軸筒５）に対する尾栓６の装着はより容易となった。 In this embodiment, a plurality of inner groove portions 2e of the rear shaft 2 are formed between adjacent ribs 2c, and the rear end portion of the inner groove portion 2e is formed to be inclined so as to be widened. At the same time, since the front end of the front first guide portion 6h1 of the tail plug 6 is also formed in a pointed shape, when the tail plug 6 is inserted into the rear shaft 2, it is inserted without aligning the rotational position in the axial direction. However, the first guide portion 6h is guided by the inner groove portion 2e so that the fitting position in the axial circumferential direction is aligned. Therefore, it became easier to attach the breech plug 6 to the rear shaft 2 (axle cylinder 5).

また、尾栓６を後軸２に取り付けた際、尾栓６の係止突起６ｇ（係止部）の後方傾斜部６ｍ（後方当接部）と、後軸２の内突起２ｄ（被係止部）の先端角部２ｇ（被当接部）と、が必ず当接するよう、尾栓６の内筒部６ｃが軸径方向に少し撓んだ状態で当接させてある。これにより、尾栓６は内筒部６ｃの撓みによる弾発力を受けて後軸２（軸筒５）に対して前方へ付勢され、尾栓６の鍔部６ｄの前端が後軸２の後端に常に当接するよう構成することで、尾栓６が軸方向にガタツクことを防止してある。 Further, when the tail plug 6 is attached to the rear shaft 2, the rear inclined portion 6 m (rear contact portion) of the locking projection 6 g (locking portion) of the tail plug 6 and the internal protrusion 2d (engaged portion) of the rear shaft 2 are engaged. The inner cylinder portion 6c of the breech plug 6 is brought into contact with the tip corner portion 2g (contacted portion) of the breech plug 6 in a slightly bent state in the axial direction so as to be in contact with the tip corner portion 2g (contacted portion). As a result, the breech plug 6 receives the elastic force due to the bending of the inner cylinder portion 6c and is urged forward with respect to the rear shaft 2 (axle cylinder 5), and the front end of the flange portion 6d of the breech plug 6 is the rear shaft. By configuring the tail plug 6 to always abut on the rear end of 2, the breech plug 6 is prevented from rattling in the axial direction.

更に、尾栓６を後軸２（軸筒５）に対して引き抜く、または、尾栓６が当該尾栓６の前端部に当接しているボールペンレフィル６により後方（図２の矢印Ｐ方向）へ押されて移動しても、図６及び図７に示すように、尾栓６の係止突起６ｇ（係止部）の後方壁部６ｎと後軸２の内突起２ｄ（被係止部）の前方壁部２ｆとが面接触することで、内突起２ｄを係止突起６ｇ（係止部）が乗り越え難くなるよう構成し、尾栓６が後軸２（軸筒５）から外れることを防止してある。
また、具体的には、後軸２に対して尾栓６を引き抜くのに必要な力（引抜力）は７５．４Ｎであり、取り付け時の押圧力１９．６Ｎと比べて高いことから、装着が容易で抜け難い筆記具となった。また、前述したように、尾栓６の係止突起６ｇ（係止部）の後方壁部６ｎと後軸２（軸筒５）の内突起２ｄ（被係止部）の前方壁部２ｆとの間の隙間の幅は０．１ｍｍであり、隙間の幅が０．２０ｍｍ以下であるため、尾栓６が後退できる距離が短いことから、尾栓６を後軸２（軸筒５）から無理に引き抜こうとしても、すぐに後方壁部６ｎと前方壁部２ｆとが当接することで勢いが付かず、尾栓の抜けを更に防止できた。 Further, the breech plug 6 is pulled out with respect to the rear shaft 2 (shaft cylinder 5), or the breech plug 6 is rearward (in the direction of arrow P in FIG. 2) by the ballpoint pen refill 6 in which the breech plug 6 is in contact with the front end portion of the breech plug 6. As shown in FIGS. 6 and 7, the rear wall portion 6n of the locking projection 6g (locking portion) of the breech plug 6 and the internal projection 2d (locked portion) of the rear shaft 2 are pushed to move. ), The inner protrusion 2d is configured to be difficult for the locking protrusion 6g (locking portion) to get over by the surface contact with the front wall portion 2f, and the tail plug 6 is detached from the rear shaft 2 (shaft cylinder 5). Is prevented.
Specifically, the force (pulling force) required to pull out the tail plug 6 with respect to the rear shaft 2 is 75.4 N, which is higher than the pushing pressure of 19.6 N at the time of mounting. It became an easy and hard-to-remove writing tool. Further, as described above, the rear wall portion 6n of the locking projection 6g (locking portion) of the tail plug 6 and the front wall portion 2f of the internal projection 2d (locked portion) of the rear shaft 2 (axle cylinder 5). Since the width of the gap between them is 0.1 mm and the width of the gap is 0.20 mm or less, the distance that the breech plug 6 can retract is short, so that the breech plug 6 is moved from the rear shaft 2 (axle cylinder 5). Even if it was forcibly pulled out, the rear wall portion 6n and the front wall portion 2f immediately came into contact with each other, so that the momentum was not gained and the breech plug could be further prevented from coming off.

尚、後方壁部６ｎと前方壁部２ｆとが接触した際に、尾栓６が後軸２に対して強く係合するように、軸径方向に延びる後方壁部６ｎ及び前方壁部２ｆを、若干傾斜させて形成してもよく、後方壁部６ｎと前方壁部２ｆとの接触面の粗さを調整して係合時の摩擦係数が高くなるよう構成してもよい。 When the rear wall portion 6n and the front wall portion 2f come into contact with each other, the rear wall portion 6n and the front wall portion 2f extending in the axial radial direction are provided so that the tail plug 6 strongly engages with the rear shaft 2. It may be formed with a slight inclination, or the roughness of the contact surface between the rear wall portion 6n and the front wall portion 2f may be adjusted so that the friction coefficient at the time of engagement becomes high.

実施例２
本発明の第二の形態としては、図８に示すように、筆記具１００は、尾栓６０の係止突起６０ｇ（係止部）の後方壁部６０ｎに、軸方向前方へ向って凹状に形成した凹部６０ｐを形成し、後軸２０の内突起２０ｄ（被係止部）の前方壁部２０ｆに、軸方向前方へ向って突出し後方壁部の凹部６０ｐと係合可能な凸状部２０ｊ（被当接部）が形成してある。
尚、尾栓６０を軸筒に取り付けた際、尾栓６０の係止突起６０ｇ（係止部）の後方傾斜部６０ｍ（後方当接部）と、後軸２の内突起２ｄ（被係止部）の凸状部２０ｊ（被当接部）と、が必ず当接するよう、尾栓６０の内筒部２０ｃが軸径方向に少し撓んだ状態で当接させてある。 Example 2
As a second aspect of the present invention, as shown in FIG. 8, the writing instrument 100 is formed in a concave shape in the axially forward direction on the rear wall portion 60n of the locking projection 60g (locking portion) of the tail plug 60. The concave portion 60p is formed, and the convex portion 20j (convex portion 20j) that protrudes forward in the axial direction on the front wall portion 20f of the inner protrusion 20d (locked portion) of the rear shaft 20 and can be engaged with the concave portion 60p of the rear wall portion. The contacted portion) is formed.
When the breech plug 60 is attached to the axle tube, the rear inclined portion 60 m (rear contact portion) of the locking projection 60 g (locking portion) of the breech plug 60 and the internal projection 2d (locked) of the rear shaft 2 are locked. The inner cylinder portion 20c of the breech plug 60 is brought into contact with the convex portion 20j (contacted portion) of the breech plug 60 in a slightly bent state in the axial direction so as to be in contact with the convex portion 20j (contacted portion).

また、本実施例では、尾栓６０を後軸２０（軸筒５０）に対して引き抜く、または、尾栓６０が当該尾栓６０の前端部に当接しているボールペンレフィル７により後方（図８の矢印Ｐ方向）へ押されて移動した際、図９及び図１０に示すように、尾栓６０の係止突起６０ｇ（係止部）の後方壁部６０ｎと後軸２０の内突起２０ｄ（被係止部）の前方壁部２０ｆとが面接触すると共に、後方壁部６０ｎに形成した凹部６０ｐに前方壁部２０ｆに形成した凹状部２０ｊが係合することで、内突起２０ｄを係止突起６０ｇ（係止部）が乗り越え難くなるよう構成し、尾栓６０が後軸２０（軸筒５０）から外れることを防止してある。
尚、本実施例において、後軸２０に尾栓６０を装着させるのに必要な押圧力は１９．６Ｎであり、後軸２０に対して尾栓６０の引き抜くのに必要な引抜力は９８．２Ｎであった。このため、本実施例を用いることで軸筒に対して尾栓が装着し易く、更に外れにくい筆記具を提供することができた。 Further, in this embodiment, the breech plug 60 is pulled out with respect to the rear shaft 20 (shaft cylinder 50), or the breech plug 60 is rearward by a ballpoint pen refill 7 in contact with the front end portion of the breech plug 60 (FIG. 8). When pushed and moved in the direction of the arrow P), as shown in FIGS. 9 and 10, the rear wall portion 60n of the locking projection 60g (locking portion) of the breech plug 60 and the internal projection 20d of the rear shaft 20 ( The inner protrusion 20d is locked by the surface contact with the front wall portion 20f of the locked portion) and the concave portion 20j formed in the front wall portion 20f engaging with the concave portion 60p formed in the rear wall portion 60n. The protrusion 60 g (locking portion) is configured to be difficult to get over, and the tail plug 60 is prevented from coming off from the rear shaft 20 (shaft cylinder 50).
In this embodiment, the pushing pressure required to attach the tail plug 60 to the rear shaft 20 is 19.6 N, and the pulling force required to pull out the tail plug 60 with respect to the rear shaft 20 is 98. It was 2N. Therefore, by using this embodiment, it is possible to provide a writing tool in which the breech plug can be easily attached to the barrel and is not easily removed.

尚、本発明に用いる筆記具としては、特に限定されることはなく、尾栓を備えた構造であれば、ボールペン、シャープペンシル、万年筆、マーカー、サインペン等に用いることができる。 The writing tool used in the present invention is not particularly limited, and can be used for a ballpoint pen, a mechanical pencil, a fountain pen, a marker, a felt-tip pen, or the like as long as it has a structure provided with a breech plug.

１…筆記具、
２…後軸、２ａ…雌螺子部、２ｂ…後部内周部、２ｃ…リブ、
２ｄ…内突起（被係止部）、２ｅ…内溝部、２ｆ…前方壁部、
２ｇ…先端角部（被当接部）、２ｈ…内側部、２ｉ…後端面、
３…前軸、３ａ…前部雄螺子部、３ｂ…後部雌螺子部、
４…先口、４ａ…雄螺子部、
５…軸筒、
６…尾栓、６ａ…内孔、６ｂ…有底部、６ｃ…内筒部、６ｄ…鍔部、６ｅ…後筒部、
６ｆ…切欠部、６ｇ…係止突起（係止部）、６ｈ…第一ガイド部、
６ｈ１…前部第一ガイド部、６ｈ２…後部第一ガイド部、６ｉ…第二ガイド部、
６ｉ１…前部第二ガイド部、６ｉ２…後部第二ガイド部、６ｊ…第一溝部、
６ｋ…第二溝部、
６ｍ…後方傾斜部（後方当接部）、６ｎ…後方壁部、
７…ボールペンレフィル、７ａ…先端部、
８…ボールペンチップ、
９…インキ収容筒、
１０…チップホルダー、
１１…コイルスプリング、
２０…後軸、２０ｄ…内突起（被係止部）、２０ｆ…前方壁部、
２０ｊ…凸状部（被当接部）、
５０…軸筒、
６０…尾栓、６０ｃ…内筒部、６０ｇ…係止突起（係止部）、
６０ｍ…後方傾斜部（後方当接部）、６０ｎ…後方壁部、６０ｐ…凸状部、
１００…筆記具。 1 ... Stationery,
2 ... Rear shaft, 2a ... Female screw part, 2b ... Rear inner peripheral part, 2c ... Rib,
2d ... Internal protrusion (locked portion), 2e ... Inner groove portion, 2f ... Front wall portion,
2g ... tip corner (contacted part), 2h ... inner part, 2i ... rear end surface,
3 ... Front shaft, 3a ... Front male screw part, 3b ... Rear female screw part,
4 ... Tip, 4a ... Male screw part,
5 ... Shaft tube,
6 ... breech plug, 6a ... inner hole, 6b ... bottomed part, 6c ... inner cylinder part, 6d ... collar part, 6e ... rear cylinder part,
6f ... notch, 6g ... locking projection (locking), 6h ... first guide,
6h1 ... front first guide part, 6h2 ... rear first guide part, 6i ... second guide part,
6i1 ... front second guide section, 6i2 ... rear second guide section, 6j ... first groove section,
6k ... Second groove,
6m ... rear inclined portion (rear contact portion), 6n ... rear wall portion,
7 ... Ballpoint pen refill, 7a ... Tip,
8 ... Ballpoint pen tip,
9 ... Ink storage cylinder,
10 ... Chip holder,
11 ... Coil spring,
20 ... Rear axle, 20d ... Internal protrusion (locked portion), 20f ... Front wall portion,
20j ... Convex part (contacted part),
50 ... Shaft tube,
60 ... Breech plug, 60c ... Inner cylinder part, 60g ... Locking protrusion (locking part),
60m ... rear inclined portion (rear contact portion), 60n ... rear wall portion, 60p ... convex portion,
100 ... Stationery.

Claims

後端部に開口部を備えた軸筒と、前記開口部に装着される尾栓と、を備えた筆記具であって、
前記尾栓が、後端に有底部を備えた筒状に形成されると共に、前記軸筒の後端部に当接する鍔部と、前記軸筒の内壁に設けた被係止部に係止する係止部と、を具備し、
前記係止部の後端に、軸方向に対して傾斜した方向に延びる後方当接部と、後方当接部の前端に連接し外方へ向って突設された後方壁部と、を備え、
前記被係止部の前端に、前記係止部の後方当接部と当接する被当接部と、前記尾栓が前記軸筒に対して後退した際、前記係止部の後方壁部に係合するよう該後方壁部の形状に合わせて形成された前方壁部と、を備え、
前記尾栓の後方壁部に、軸方向後方に向って突出する凸部、または、軸方向前方へ向かって凹む凹部が形成され、
前記軸筒の前方壁部に、軸方向後方へ向って凹み前記後方壁部の凸部と係合する凹状部、または、軸方向前方へ向って突出し前記後方壁部の凹部と係合する凸状部が形成されたことを特徴としたことを特徴とする筆記具。 A writing instrument provided with a shaft tube having an opening at the rear end and a breech plug attached to the opening.
The breech plug is formed in a tubular shape having a bottomed portion at the rear end, and is locked to a flange portion that abuts on the rear end portion of the shaft cylinder and a locked portion provided on the inner wall of the shaft cylinder. With a locking part,
The rear end of the locking portion is provided with a rear contact portion extending in a direction inclined with respect to the axial direction, and a rear wall portion connected to the front end of the rear contact portion and projecting outward. ,
At the front end of the locked portion, the contacted portion that comes into contact with the rear contact portion of the locked portion and the rear wall portion of the locked portion when the tail plug retracts with respect to the barrel. A front wall portion formed to match the shape of the rear wall portion so as to be engaged is provided.
The rear wall portion of the breech plug is formed with a convex portion that protrudes rearward in the axial direction or a concave portion that is recessed toward the front in the axial direction.
A concave portion that dents backward in the axial direction and engages with the convex portion of the rear wall portion, or a convex portion that protrudes forward in the axial direction and engages with the concave portion of the rear wall portion. A writing tool characterized by the formation of a shaped part .

後端部に開口部を備えた軸筒と、前記開口部に装着される尾栓と、を備えた筆記具であって、A writing instrument provided with a shaft tube having an opening at the rear end and a breech plug attached to the opening.
前記尾栓が、後端に有底部を備えた筒状に形成されると共に、前記軸筒の後端部に当接する鍔部と、前記軸筒の内壁に設けた被係止部に係止する係止部と、外周部に外方へ向って突出すると共に軸方向に沿って延びるよう形成されたガイド部と、を具備し、The breech plug is formed in a tubular shape having a bottomed portion at the rear end, and is locked to a flange portion that abuts on the rear end portion of the shaft cylinder and a locked portion provided on the inner wall of the shaft cylinder. It is provided with a locking portion for locking and a guide portion formed so as to project outward and extend along the axial direction on the outer peripheral portion.
前記係止部の後端に、軸方向に対して傾斜した方向に延びる後方当接部と、後方当接部の前端に連接し外方へ向って突設された後方壁部と、を備え、 The rear end of the locking portion is provided with a rear contact portion extending in a direction inclined with respect to the axial direction, and a rear wall portion connected to the front end of the rear contact portion and projecting outward. ,
前記被係止部の前端に、前記係止部の後方当接部と当接する被当接部と、前記尾栓が前記軸筒に対して後退した際、前記係止部の後方壁部に係合するよう該後方壁部の形状に合わせて形成された前方壁部と、を備え、At the front end of the locked portion, the contacted portion that comes into contact with the rear contact portion of the locked portion and the rear wall portion of the locked portion when the tail plug retracts with respect to the barrel. A front wall portion formed to match the shape of the rear wall portion so as to be engaged is provided.
前記ガイド部が、軸方向に分断されていることを特徴とする筆記具。A writing tool characterized in that the guide portion is divided in the axial direction.

前記尾栓の後方当接部と前記軸筒の被当接部とが当接した状態では、前記軸筒の前方壁部と前記尾栓の後方壁部との間に形成される隙間が０．０４ｍｍ以上、０．２０ｍｍ以下となることを特徴とする請求項１または２に記載の筆記具。 In a state where the rear contact portion of the breech plug and the contacted portion of the breech plug are in contact with each other, the gap formed between the front wall portion of the breech plug and the rear wall portion of the breech plug is 0. The writing tool according to claim 1 or 2, wherein the writing tool is .04 mm or more and 0.20 mm or less.