CN211364058U - pen tool - Google Patents

Abstract

The utility model provides a pen tool, this pen tool can not rely on the mode of exerting of power to the frictional body, and the frictional body is firmly fixed and is restrained rotatoryly. A mounting hole which opens rearward of the shaft is provided at the rear end of the barrel of the pen, a friction body made of an elastic material is inserted into the mounting hole, an inward protrusion is formed on the inner peripheral surface of the mounting hole, an outward protrusion is formed on the outer peripheral surface of the friction body, and the outward protrusion and the inward protrusion are locked in the front-rear direction. The friction body has a friction portion projecting axially rearward from the rear end of the cylindrical body, and a front projection on the front end surface of the friction portion. The barrel has a rear protrusion on a rear end surface of the barrel. The front projection and the rear projection are engaged with each other in a rotational direction around the axis.

Description

pen tool

technical field

The utility model relates to a pen tool. More specifically, the present invention relates to a writing instrument in which a mounting hole opening axially rearward is provided at the rear end of a cylindrical body such as a barrel of the writing instrument or a pen cover, and a friction body is inserted into the mounting hole.

Background technique

Patent Document 1 describes the attachment structure for a soft member, in which an attachment hole opening in the axial direction upward is provided at the upper end of a cylindrical body such as a barrel of a writing instrument, a pen cover, and the like, and a soft member is inserted into the attachment hole. The installation structure of a soft member made of a solid member is characterized in that an inward protrusion is formed on the inner peripheral surface of the installation hole, and an outward protrusion is formed on the outer peripheral surface of the soft member, and the outward protrusion is formed. The inwardly directed protrusion is crossed from above to below.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2007-144991

Utility model content

The technology disclosed in Patent Document 1 has a structure in which the outer peripheral surface (ie, the soft member) of the rear end portion of the small diameter portion (corresponding to the insertion portion of the present invention) of the soft member (corresponding to the friction body of the present invention) The outer peripheral surface of the connecting portion between the shoulders of the small-diameter portion and the large-diameter portion (equivalent to the friction portion of the present invention) forms an inclined surface shape (that is, a conical surface shape) whose outer diameter gradually increases as it approaches the top. ), when the soft member is inserted into the mounting hole, the inclined surface-shaped base is pressed against the opening edge of the mounting hole, but depending on how the force is applied to the soft member, it may violate the user during friction. will rotate. In particular, when the friction portion has a non-circular shape in cross section, rotation is likely to occur.

The present invention solves the above-mentioned conventional problems, and aims to provide a writing instrument in which the friction body is firmly fixed and the rotation of the friction body is suppressed during friction, regardless of the application method of force to the friction body.

In the present invention, "rear" means the friction body side in the whole pen tool, and "front" means the side opposite to the friction body side. In addition, in the present invention, "the pen tip entering state" means the state in which the pen tip enters the shaft barrel, and the "pen tip protruding state" means the state where the pen tip protrudes from the front end hole of the shaft tube to the outside.

The utility model provides a pen tool. An installation hole is arranged at the rear end of the shaft cylinder of the pen tool or the cylinder body of the pen sleeve, which is open to the rear in the axial direction. The friction body is characterized in that an inward projection is formed on the inner peripheral surface of the installation hole, an outward projection is formed on the outer peripheral surface of the friction body, and the outward projection and the inward projection are formed. To be locked in the front-rear direction, the friction body includes a friction portion protruding axially rearward from a rear end of the cylindrical body, and a front end surface of the friction portion includes a forward protrusion, where the cylindrical body is located. The rear end surface of the cylindrical body is provided with rear projections, and the front projections and the rear projections are respectively engaged with each other in the rotational direction around the axis.

In the pen tool of the present invention, the outer surface of the friction portion may have a non-circular cross-sectional shape.

In the writing instrument of the present invention, the inner peripheral surface of the mounting hole of the cylindrical body may have a circular cross-sectional shape, and the friction body may include an insertion portion that extends forward from the friction portion. It is integrally connected and inserted into the installation hole, the outer surface of the insertion portion has a circular cross-sectional shape, and the outward protrusion is formed on the outer peripheral surface of the insertion portion.

In the writing instrument of the present invention, the inserting portion may include: a base portion formed on the outer peripheral surface of the rear end portion of the inserting portion, which is connected to the inner peripheral surface of the opening edge of the mounting hole during non-friction. a non-contact; and a contact portion formed on the rear end portion of the base portion to be in contact with the inner peripheral surface of the opening edge of the mounting hole when rubbed.

In the pen tool of the present invention, the insertion portion may further include a middle portion, and the outer diameter of the middle portion is set to be smaller than the inner diameter of the rear portion of the mounting hole relative to the inward protrusion. , so as to form an annular space between the outer peripheral surface of the insertion portion rearward of the outward projection and the inner peripheral surface of the mounting hole rearward of the inward projection.

In the writing instrument of the present invention, the outward projection may include: a guide part formed of an inclined surface whose outer diameter gradually increases as it approaches the rear; and an outer diameter part formed at a distance larger than the guide part. The outer diameter of the outer diameter portion of the outward protrusion is set to be larger than the inner diameter of the inward protrusion and smaller than the inner diameter of the mounting hole rearward of the inward protrusion .

In the writing instrument of the present invention, the front end of the friction body may be formed with a shoulder portion capable of abutting with the opening end of the mounting hole, from the shoulder portion of the friction body to the outward protrusion The axial length of the rear end of the barrel is set to be greater than the axial length from the rear end of the cylinder to the inwardly protruding front end of the mounting hole.

In the pen tool of the present invention, an axially extending inner hole may be formed inside the friction body.

In the writing instrument of the present invention, the front protrusions may be a pair of circumferential protrusions protruding forward from the friction portion, and each end portion in the circumferential direction may have an inclined surface, and the rearward protrusions may be provided with inclined surfaces. The protrusions are a pair of triangular protrusions protruding rearward from the rear end of the cylinder.

In the writing instrument of the present invention, the front protrusion may be a circumferential protrusion having an inclined surface that protrudes forward from the friction portion, and the rear protrusion may be a protrusion provided from the cylindrical body. The rear end faces the circumferential convex portion of the inclined surface that protrudes rearward.

According to the utility model, in the pen tool, an inward protrusion is formed on the inner peripheral surface of the installation hole, an outward protrusion is formed on the outer peripheral surface of the friction body, and the outward protrusion is formed with the outer peripheral surface of the friction body. The inward protrusion is locked in the front-rear direction, the friction body includes a friction portion protruding axially rearward from the rear end of the cylindrical body, and a front protrusion is provided on the front end surface of the friction portion, The cylindrical body is provided with rear projections on the rear end surface of the cylindrical body, and the front projections and the rear projections are respectively engaged in the rotation direction around the axis, thereby suppressing the rotation of the friction body, The friction body is firmly fixed and prevented from rotating independently of the manner in which the force is applied to the friction body.

According to the writing instrument of the present invention, the friction body can be firmly fixed and the rotation can be suppressed regardless of the manner in which the force is applied to the friction body.

Description of drawings

FIG. 1 is a vertical cross-sectional view of the writing instrument according to the first embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of a main part of FIG. 1 .

FIG. 3 is an enlarged vertical cross-sectional view of a main part of FIG. 1 .

FIG. 4 is an enlarged vertical cross-sectional view of a main part at the time of friction in FIG. 1 .

Fig. 5(a) is an enlarged front view of the writing instrument (friction body) according to the first embodiment of the present invention. Fig. 5(b) is an enlarged side view of the writing instrument (friction body) according to the first embodiment of the present invention. Fig. 5(c) is a cross-sectional view taken along the line A-A of Fig. 5(a). Fig. 5(d) is a cross-sectional view taken along the line B-B of Fig. 5(a).

6 is an enlarged perspective view of the writing tool (friction body) according to the first embodiment.

(a) of FIG. 7 is an enlarged front view of the writing instrument (friction body) according to the second embodiment of the present invention. FIG.7(b) is an enlarged side view of the writing implement (friction body) of 2nd Embodiment of this invention. Fig. 7(c) is a cross-sectional view taken along the line C-C of Fig. 7(a). Fig. 7(d) is a cross-sectional view taken along the line D-D in Fig. 7(a) .

8 is an enlarged perspective view of a writing instrument (friction body) according to a second embodiment.

Description of reference numerals

1 pen; 2 barrel; 2a front axle; 2b intermediate axle; 2c rear axle; 21 front end hole; 22 sliding hole; 23 mounting hole; Start; 3 Pen body; 31 Pen tip; 32 Ink storage tube; 4 Operation part; 41 Operation base part; 42 Ball part; 43 Shaft part; 44 Clip part; 72 Friction part; 73 Shoulder part; 74 Insertion part; 75 Protrusion outward; 75a Guide part; ;A the axial length from the front end of the friction part to the rear end that protrudes outwards; B the axial length from the rear end of the cylinder to the front end that protrudes inwards; C axial clearance; a middle part of the insertion part the outer diameter of the mounting hole; b the inner diameter of the rear portion of the mounting hole that projects inwards.

Detailed ways

Hereinafter, two embodiments of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>

A first embodiment of the present invention is shown in FIGS. 1 to 6 .

The writing instrument 1 of the present embodiment includes a cylindrical body 2 , a pen body 3 accommodated in the cylindrical body 2 , and an in-out mechanism for allowing the pen tip 31 of the pen body 3 to enter and exit from the front end hole 21 of the cylindrical body 2 .

·Body

The pen body 3 includes a pen tip 31, an ink accommodating tube 32 to which the pen tip 31 is press-fitted and fixedly mounted at the front end opening, a thermochromic ink filled in the ink accommodating tube 32, and a rear end filled with the thermochromic ink. A follower (eg, a high-viscosity fluid) that ends and advances as the thermochromic ink is consumed.

For example, the pen tip 31 may be any structure consisting of only a metal ballpoint pen tip that rotatably holds a ball at the front end, or a structure consisting of a synthetic resin pen tip holder that holds the rear outer surface of the ballpoint pen tip. . In addition, a tail plug is attached to the rear end opening of the ink accommodating tube 32 , and the tail plug is provided with a ventilation hole for allowing the ink accommodating tube 32 to ventilate to the outside. Inside the pen tip 31 is accommodated a spring for pressing the ball at the tip forward. The spring has a structure including a rod portion at the front end portion of the compression coil spring, and the front end of the rod portion is in contact with the rear surface of the ball. During non-writing, the ball is in close contact with the inner surface of the inward tip edge portion of the tip of the ballpoint pen tip by the forward force of the spring, thereby preventing ink leakage and ink evaporation from the tip of the pen tip 31 .

·Cylinder

The cylindrical body 2 includes a front thin cylindrical front shaft 2a, a cylindrical intermediate shaft 2b connected to the rear end of the front shaft 2a, and a cylindrical rear shaft connected to the rear end of the intermediate shaft 2b 2c. A sliding hole 22 extending in the axial direction is formed in the side wall of the cylindrical body 2 (for example, the side wall of the intermediate shaft 2 b and the side wall of the rear shaft 2 c ). A mounting hole 23 is provided axially through the rear end of the cylindrical body 2 (that is, the rear end of the rear axle 2c). The friction body 7 made of an elastic material is press-fitted into the attachment hole 23 . The friction body 7 is fixed to the outer surface of the rear end of the rear axle 2c (the cylindrical body 2 ) without interlocking with the axial movement of the operation part 4 . The friction body 7 and the operation part 4 are provided independently. In addition, the cylindrical body of the present invention may be a cylindrical body such as a pen cover of a writing instrument.

· Raised rear

As shown in FIG. 5 , the cylindrical body 2 includes a rear projection 25 on the rear end surface. The rear projections 25 in the present embodiment are a pair of triangular projections projecting rearward from the rear end surface of the cylindrical body 2 . The rear bosses 25 and the front bosses 78 to be described later mesh with each other in the rotational direction around the axis, thereby suppressing the friction body 7 from rotating around the axis regardless of how force is applied to the friction body 7 . In addition, as a matter of course, the shape of the rear projection 25 is not limited to the shape shown in the figure, for example, it may be a semicircular shape, a quadrangular shape, or other polygonal shapes, and the number thereof is also not limited.

·Bulges inwards

An annular inward projection 24 is integrally formed on the inner peripheral surface of the mounting hole 23 . The inward projection 24 has a guide portion 24a formed of an inclined surface (ie, a conical surface) whose inner diameter gradually decreases as it approaches the front. In addition, the inward projection 24 has a front end surface formed of a surface perpendicular to the axis in front of the guide portion 24a. A minimum inner diameter portion 24b formed by an acute-angled corner portion is formed between the guide portion 24a and the front end surface.

·In and out of institutions

The in-out mechanism is a side-sliding in-out mechanism using a rotating cam mechanism. The entry and exit mechanism includes a cam portion formed on the inner surface of the intermediate shaft 2b, a rotating member 5 that cooperates with the cam portion and abuts the rear end of the pen body 3, and cooperates with the rotating member 5 and extends radially outward from the sliding hole 22. The protruding operation part 4 and the elastic pressing body 6 (for example, a compression coil spring) which is accommodated in the cylinder body 2 and urges the pen body 3 rearwardly. The entry-exit mechanism of the present embodiment is a double-tap mechanism in which the operation part 4 is slid forward in both the protruding operation of the pen tip and the entering operation of the pen tip. The rotating member 5 is formed of a molded body of synthetic resin (eg, polyacetal resin).

The cam portion includes a plurality of serrated cam teeth protruding forward, and a plurality of cam grooves formed between the cam teeth and extending in the axial direction. The rotating member 5 includes, on the outer surface thereof, a plurality of (for example, four) protruding bars extending in the axial direction, and the protruding bars are engaged with the cam teeth of the cam portion and the cam grooves of the cam portion. At the front end of the shaft portion 43 of the operation portion 4 , cam teeth that engage with the rear end of the protruding bar of the rotating member 5 are formed integrally or by attaching a separate member.

·Operation Department

The operating portion 4 includes an operating base portion 41 that protrudes radially outward from the sliding hole 22 extending in the axial direction of the side wall of the cylindrical body 2 . In addition, the operation part 4 includes: a shaft part 43 connected to the operation base 41 and accommodated in the cylindrical body 2 so as to be axially movable; and a clip part 44 connected to the front of the operation base 41 . The clip portion 44 can hold clothes such as pockets. The operation portion 4 is obtained from a molded body of synthetic resin (eg, polycarbonate resin). A ball portion 42 is protruded from the inner surface (inner surface) of the clip portion 44 . The operation base 41 and the shaft part 43 , the operation base 41 and the clip part 44 , and the clip part 44 and the ball part 42 are formed integrally by one member or formed by assembling two separate members, respectively.

The operation base 41 is axially movable along the sliding hole 22 . By pressing the operation base 41 forward, the pen tip 31 of the pen body 3 can be freely inserted and withdrawn from the front end hole 21 of the cylindrical body 2 .

·In and out of the nib

When the operation base 41 of the operation part 4 is slid forward from the pen tip entry state against the rearward urging force of the pressing body 6, the rotation member 5 is pressed forward by the cam teeth of the shaft part 43 of the operation part 4, and the rotation of the rotation member 5 is pushed forward. The protrusion moves forward along the cam groove, and the rotating member 5 presses the rear end of the pen body 3 forward along with this, and the pen tip 31 protrudes from the front end hole 21 to the outside. At this time, since the cam teeth of the shaft portion 43 come into contact with the protrusions of the rotating member 5 , the rotating member 5 is rotated by a certain angle with respect to the cam portion. Thereby, the protrusion of the rotating member 5 is engaged with the cam teeth of the cam portion, and the pen tip is maintained in a protruding state.

When the operation base 41 of the operation part 4 is slid forward from the protruding state of the pen tip, the shaft part 43 of the operation part 4 presses the rotating member 5 forward, and the cam teeth of the shaft part 43 abut against the protrusions of the rotating member 5, This rotating member 5 is rotated by a certain angle with respect to the cam portion. Thereby, the engagement state of the protrusion and the cam teeth of the cam portion is released, and the protrusion is moved rearward along the cam groove of the cam portion by the backward biasing force of the biasing body 6 . Along with the backward movement of the rotating member 5 , the pen body 3 moves backward, and the pen tip enters a state.

· Friction body

The friction body 7 includes a friction part 72 and an insertion part 74 integrally connected and provided in front of the friction part 72 , and is integrally formed with an elastic material. In the present embodiment, the friction body 7 is a friction discoloration member that wipes off the surface of thermochromic handwriting to thermally discolor the handwriting. The outer surface of the friction portion 72 has a non-circular shape in cross section (refer to (c) of FIG. 5 or (c) of FIG. 7 ). In addition, as a matter of course, the cross-sectional non-circular shape is not limited to the shape shown in the figure, and may be other polygonal shapes such as a triangular shape, a quadrangular shape, and a hexagonal shape, for example. Thereby, by using an appropriate part of the friction body, the handwriting of the thermochromic ink can be wiped off only in the part desired by the user, and it is possible to prevent excessive thermochromic discoloration.

The friction body 7 is formed with outward protrusions 75 on the outer peripheral surface, and the outward protrusions 75 and the inward protrusions 24 are locked in the front-rear direction. In addition, the friction body 7 includes a friction portion 72 projecting axially rearward from the rear end of the cylindrical body 2 , and further includes a front projection 78 on the front end surface of the friction portion 72 . The front protrusions 78 and the rear protrusions 25 are respectively engaged in the rotation direction about the axis, thereby suppressing the friction body 7 from rotating about the axis regardless of the manner in which the force is applied to the friction body 7 . The outward protrusions 75 and the inward protrusions 24 are locked in the front-rear direction, and the front protrusions 78 and the rear protrusions 25 are respectively engaged in the rotation direction centered on the axis, so that the friction body 7 can be firmly fixed to the friction body 7. Cylinder 2.

· Front bump

As shown in FIG. 5 , the friction body 7 includes a front protrusion 78 on the front end surface of the friction portion 72 . The front protrusions 78 in the present embodiment are a pair of circumferentially-shaped protrusions that protrude forward from the friction portion 72, and each end portion in the circumferential direction is provided with an inclined surface. In other words, the friction body 7 is provided with a pair of triangular-shaped recessed parts from the front end of the friction part 72 toward the rear. The front protrusions 78 mesh with the aforementioned rear protrusions 25 in the rotational direction around the axis, thereby suppressing the friction body 7 from rotating around the axis regardless of the manner in which the force is applied to the friction body 7 . In addition, as a matter of course, the shape of the rear projection 25 is not limited to the shape shown in the figure, for example, it may be a semicircular shape, a quadrangular shape, or other polygonal shapes, and the number thereof is also not limited.

FIG. 5 is an enlarged view of the writing instrument 1 (friction body 7 ) according to the first embodiment of the present invention, and FIG. 6 is a perspective view of FIG. 5 . As shown in FIGS. 5 and 6 , the friction body 7 is formed so that, in a state of being attached to the cylindrical body 2 (the rear axle 2 c ), the cross-sectional shape of the friction portion 72 exposed from the cylindrical body 2 is substantially rectangular ( FIG. 5 ). (c)). Specifically, in cross section, the apex of the rectangle is formed in a circular arc shape, and the curvature radius of the arc is larger than the curvature radius of the front end of the friction portion 72 of the friction body 7 . Therefore, the friction body 7 according to the first embodiment of the present invention has a substantially rectangular cross-section, and when rubbing is performed on the short side of the substantially rectangular shape of the transverse cross-section, the friction can be concentrated in a narrow range. When the long side of the substantially rectangular shape is rubbed, a wide range can be quickly rubbed, so that the user's desired rubbing operation can be performed. In addition, the cross-sectional shape of the friction portion 72 is not limited to a substantially rectangular shape, and may be an ellipse, a quadrangle, a hexagon, or other polygons.

In addition, preferably, the inner peripheral surface of the mounting hole 23 of the cylindrical body 2 has a circular cross-sectional shape, and the friction body 7 includes an insertion portion 74 that is integrally connected to the front from the friction portion 72 and is inserted into the mounting hole 23, The outer surface of the insertion portion 74 has a circular cross-sectional shape, and outward protrusions 75 are formed on the outer peripheral surface of the insertion portion 74 . As a result, the friction body 7 is stably mounted in the mounting hole 23 , and the front bosses 78 and the rear bosses 25 can be meshed with each other in the rotational direction about the axis center more firmly. However, even if an injection-molded port or the like is provided on the outer surface of the insertion portion 74, the above-mentioned structure is satisfied, and the above-mentioned effects are not hindered.

Preferably, the friction body 7 has a base 77 formed on the outer peripheral surface of the rear end of the insertion portion 74 , and the base 77 of the insertion portion 74 does not contact the inner peripheral surface of the opening edge of the mounting hole 23 during non-friction. Thereby, the insertion resistance at the time of inserting the friction body 7 is reduced, and the assemblability is improved.

Moreover, it is preferable to have the contact part 79 which the base part 77 of the insertion part 74 contacts the inner peripheral surface of the opening edge of the attachment hole 23 when the paper surface 8 is rubbed. Accordingly, resistance is generated between the base portion 77 of the insertion portion 74 and the inner peripheral surface of the opening edge of the mounting hole 23 , and the friction body 7 can be further prevented from unintentionally rotating around the axis during friction.

In addition, it is preferable that the cylindrical body 2 in which the friction body 7 is inserted is detachable with respect to the writing instrument 1 . Thereby, when the friction body 7 is worn out, the friction body 7 can be easily replaced with a new one. In addition, the user can select and replace the desired shape of the friction body 7 for use. The cylindrical body 2 which is detachable and has the friction body 7 inserted thereinto is attached to the writing instrument 1 through detachable screw connection or fitting.

In the present embodiment, the elastic material constituting the friction body 7 is preferably an elastic synthetic resin (rubber, synthetic rubber), for example, silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS Resin (styrene-ethylene-butylene-styrene copolymer), fluorine resin, chloroprene resin, nitrile resin, polyester resin, ethylene propylene diene rubber (EPDM), etc. The elastic synthetic resin constituting the friction body 7 is preferably made of low-abrasive elasticity that hardly generates wear debris (rubbing debris) during friction, compared to a material composed of a high-abrasion elastic material (eg, rubber, etc.). material formation.

· Friction part

The rear surface of the friction portion 72 is convexly curved. The front end of the friction part 72 is formed with a shoulder part 73 which can be brought into contact with the open end of the attachment hole 23 (specifically, the rear end of the rear axle 2c). The maximum outer diameter of the friction portion 72 is set larger than the inner diameter of the mounting hole 23 and smaller than the outer diameter of the rear end of the rear axle 2c.

·Instrumentation Department

An annular outward projection 75 is integrally formed on the outer peripheral surface of the front end portion of the insertion portion 74 . The outward projection 75 has a guide portion 75a formed of an inclined surface (ie, a conical surface) whose outer diameter gradually increases as it approaches the rear. The outward projection 75 has a rear end surface constituted by a surface perpendicular to the axis. An acute-angled corner portion is formed between the guide portion 75a and the rear end surface. The corner portion becomes the largest outer diameter portion 75b in the outward projection 75 . That is, the outward protrusion 75 includes a guide portion 75a formed of an inclined surface whose outer diameter gradually increases toward the rear, and a maximum outer diameter portion 75b formed rearward of the guide portion 75a.

The maximum outer diameter of the outward projection 75 is set larger than the minimum inner diameter of the inward projection 24 and smaller than the inner diameter b of the mounting hole 23 rearward of the inward projection 24 . In the present embodiment, the maximum outer diameter of the outward projection 75 (ie, the outer diameter of the maximum outer diameter portion 75b) is set to 4.9 mm, and the minimum inner diameter of the inward projection 24 (that is, the inner diameter of the minimum inner diameter portion 24b) is set to 4.9 mm. Set at 4.1mm. The difference between the maximum outer diameter of the outward projection 75 and the minimum inner diameter of the inward projection 24 is preferably in the range of 0.5 mm to 2 mm (preferably 0.5 mm to 1 mm). Thereby, the friction body 7 can be reliably prevented from falling off, and the smooth passing between the outward protrusions 75 and the inward protrusions 24 can be achieved.

An axially extending inner hole 71 is formed inside the friction body 7 . The front end of the inner hole 71 is opened axially forward. The rear end of the inner hole 71 is located inside the friction portion 72 . Through the inner hole 71 , the friction body 7 is formed in a bottomed cylindrical shape with a closed rear end and an open front end. In this embodiment, the inner hole 71 is formed at least on the radial inner side of the outward protrusion 75 , so that the outward protrusion 75 can be easily elastically deformed radially inward when the outward protrusion 75 passes over the inward protrusion 24 . .

·Annular space

The outer diameter a of the intermediate portion of the insertion portion 74 (ie, the portion between the outward projection 75 and the shoulder portion 73 ) is set to be smaller than the inner diameter b of the rear portion of the mounting hole 23 relative to the inward projection 24 . Accordingly, when the outward protrusion 75 just before the outward protrusion 75 passes over the inward protrusion 24 and contacts the inward protrusion 24 , the outer peripheral surface of the insertion portion 74 that is behind the outward protrusion 75 An annular space 76 is formed between the inner peripheral surface of the mounting hole 23 rearward of the inward projection 24 .

As shown in FIG. 2 , even before the outward protrusion 75 is about to pass over the inward protrusion 24, when the outward protrusion 75 is strongly pressed against the inward protrusion 24, the rearward insertion of the outward protrusion 75 The portion 74 bulges outward in the radial direction due to elastic deformation, and since the annular space 76 is formed, the outer peripheral surface of the insertion portion 74 behind the outward projection 75 will not be strongly pressed against the inner peripheral surface of the mounting hole 23. There is no possibility of becoming an impedance when the friction body 7 is inserted. As a result, the outward protrusion 75 and the inward protrusion 24 can be smoothly passed over. Specifically, the outer diameter a was set to 4.9 mm, and the inner diameter b was set to 5.6 mm.

·Axial clearance

As shown in FIG. 3, the axial length A from the shoulder portion 73 of the friction body 7 to the rear end of the outward projection 75 (ie, the maximum outer diameter portion 75b) is set to be slightly larger than that from the rear end of the rear axle 2c to The axial length B of the front end (ie, the smallest inner diameter portion 24b ) of the inward projection 24 of the mounting hole 23 (see FIG. 3 ). Thereby, when the outward protrusion 75 passes over the inward protrusion 24, even if it is difficult to slide between the outward protrusion 75 and the inward protrusion 24, the outward protrusion can be made without applying lubricant or the like. The lift 75 reliably passes over the inwardly facing projection 24 .

As shown in FIG. 3 , in the state where the insertion of the friction body 7 into the mounting hole 23 is completed, the rear end (ie, the largest outer diameter portion 75 b ) of the outward projection 75 is located more than the front end (ie, the smallest diameter portion 75 b ) of the outward projection 24 . At the front of the inner diameter portion 24 b ), an axial gap C is formed between the front end of the inward projection 24 and the rear end of the outward projection 75 . Specifically, the axial clearance C is effective in the range of 0.05 mm to 1.0 mm (preferably 0.1 mm to 0.5 mm). Due to the size of the axial gap C, there will be no large axial shaking when the friction body 7 is used, and reliable crossing between the inward protrusion 24 and the outward protrusion 75 when the friction body 7 is inserted can be achieved. . In this embodiment, specifically, the axial length A is set to 8 mm, and the axial length B is set to 7.9 mm.

In addition, in the state where the overshoot of the outward protrusion 75 and the inward protrusion 24 is completed, the inward protrusion 24 is press-contacted to the outer peripheral surface of the insertion portion 74 rearward of the outward protrusion 75 . Thereby, rattling of the insertion portion 74 in the axial direction and the radial direction can be prevented. In addition, the rear end of the rear axle 2c is press-contacted to the shoulder portion 73 in a state where the overshoot of the outward protrusion 75 and the inward protrusion 24 is completed. Thereby, it is possible to prevent the friction portion 72 from entering the mounting hole 23 and to prevent the friction portion 72 from rattling in the radial direction.

<Second Embodiment>

A second embodiment of the present invention is shown in FIGS. 7 and 8 . This is a modification of the first embodiment, and differs from the first embodiment in the shapes of the rear projections 25 and the front projections 78 . The other structures and functions and effects are the same as those of the first embodiment, so the description thereof is omitted.

· Raised rear

As shown in FIG. 7 , the cylindrical body 2 includes a rear projection 25 on the rear end surface. The rear projection 25 of the present embodiment is a circumferential projection having one inclined surface projecting rearward from the rear end surface of the cylindrical body 2 .

· Front bump

As shown in FIG. 7 , the friction body 7 includes a front protrusion 78 on the front end surface of the friction portion 72 . The front protrusion 78 in the present embodiment is a circumferential protrusion having one inclined surface that protrudes forward from the friction portion 72 . The outward protrusions 75 and the inward protrusions 24 are locked in the front-rear direction, and the front protrusions 78 and the rear protrusions 25 are respectively engaged in the rotation direction centered on the axis, so that the friction body 7 can be firmly fixed to the friction body 7. The cylindrical body 2 suppresses the rotation of the friction body 7 around the axis center, independently of the manner in which the force is applied to the friction body 7 .

Claims (10)

1. A pen tool, the rear end of the barrel of the pen tool or the barrel of the pen sleeve is provided with a mounting hole that opens to the rear in the axial direction, and a friction body formed of an elastic material is inserted in the mounting hole, It is characterized in that, An inward projection is formed on the inner peripheral surface of the mounting hole, an outward projection is formed on the outer peripheral surface of the friction body, and the outward projection and the inward projection are locked in the front-rear direction. , The friction body includes a friction portion protruding axially rearward from a rear end of the cylindrical body, and a front protrusion is provided on a front end surface of the friction portion, The cylindrical body is provided with a rear projection on the rear end surface of the cylindrical body, The front protrusions and the rear protrusions are respectively engaged with each other in the rotation direction with the axis as the center. 2. pen tool according to claim 1, is characterized in that, The outer surface of the friction portion has a cross-sectional non-circular shape. 3. pen tool according to claim 1 or 2, is characterized in that, The inner peripheral surface of the mounting hole of the cylindrical body has a circular cross-sectional shape, The friction body is provided with an insertion part, the insertion part is integrally connected to the front from the friction part and is inserted into the installation hole, The outer surface of the insertion portion has a circular cross-sectional shape, and the outward protrusion is formed on the outer peripheral surface of the insertion portion. 4. pen tool according to claim 3, is characterized in that, The inserting part includes: a base portion formed on the outer peripheral surface of the rear end portion of the insertion portion, and non-contacting with the inner peripheral surface of the opening edge of the mounting hole during non-friction; and The contact portion is formed at the rear end portion of the base portion, and is in contact with the inner peripheral surface of the opening edge of the mounting hole when rubbed. 5. pen tool according to claim 4, is characterized in that, The insertion part also includes an intermediate part, The outer diameter of the intermediate portion is set to be smaller than the inner diameter of the portion of the mounting hole that is rearward of the inward projection, so that the outer peripheral surface of the insertion portion rearward of the outward projection is connected to the outer peripheral surface of the insertion portion. An annular space is formed between inner peripheral surfaces of the mounting holes rearward of the inward projections. 6. The pen tool according to claim 1, characterized in that, The outward protrusion has: The guide portion is constituted by an inclined surface whose outer diameter gradually increases as it approaches the rear; and The outer diameter portion is formed at the rear of the guide portion, The outer diameter of the outer diameter portion of the outward projection is set to be larger than the inner diameter of the inward projection and smaller than the inner diameter of the mounting hole rearward of the inward projection. 7. The pen tool according to claim 6, characterized in that, The front end of the friction body is formed with a shoulder that can abut against the opening end of the mounting hole, The axial length from the shoulder of the friction body to the rear end of the outward projection is set to be greater than the axial length from the rear end of the cylinder body to the front end of the inward projection of the mounting hole length. 8. The pen tool according to claim 1, wherein An axially extending inner hole is formed inside the friction body. 9. The pen tool according to claim 1, characterized in that, The front protrusions are a pair of circumferentially-shaped protrusions that protrude forward from the friction portion, and each end portion in the circumferential direction is provided with an inclined surface, The rear protrusions are a pair of triangular protrusions protruding rearward from the rear end of the cylinder. 10. The pen tool according to claim 1, characterized in that, The front protrusion is a circumferential protrusion having an inclined surface protruding forward from the friction portion, The rear projection is a circumferential projection having an inclined surface projecting rearward from the rear end surface of the cylindrical body.

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