JP2002113987A - Mechanical pencil and manufacturing method of lead protective member thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of the lead protective member of a mechanical pencil, with which the effective use of a remaining lead can be realized without impairing the strength of the lead, further no shaky feeling of the remaining lead at writing develops and no lead holding force rises. SOLUTION: In the mechanical pencil, in which a lead is delivered by a lead delivering mechanism arranged in a barrel, as the lead protective member, a member, in which a longitudinal hole is bored by removing some part of a resin filled in the lead protective member, or a resin pipe, at least on the outside of which metal is covered or a resin pipe, at least on the outside of which an electroconductive film is formed and futher metal is covered on the electroconductive film, is employed. Furthermore, the shaky motion of the remaining lead can be eliminated by narrowing the diameter of the inscribed circle of the tip part of the lead protective member by removing some part of the resin layer of the tip part of the lead protective member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical pencil in which a lead is extended from a lead protecting member disposed at the tip of a barrel by moving forward and backward a lead feeding mechanism disposed in the barrel, and a lead protection for the pencil. The present invention relates to a method for manufacturing a member.

[0002]

2. Description of the Related Art A mechanical pencil will be described with reference to FIG. This kind of mechanical pencil uses a centering mechanism 4 composed of a chuck 2 such as a three-piece chuck and a ball chuck, and a chuck fastening member 3.
The core is paid out. When the lead is fed out, the chuck 2 is held in a state where the lead L is gripped by the chuck fastening member 3.
Are moved forward against a repelling force of a repelling member (not shown), and after a predetermined distance, the movement of the chuck fastening member 3 is prevented (the step of the tip member 5 fixed to the barrel 1 in the figure). Then, when the chuck 2 is further advanced, the chuck 2 is opened. In this state, when the movement of the chuck 2 is released, the chuck 2 engages with the chuck tightening member 3 by the elastic force of the elastic member. The lead L is held by the detent member S formed of rubber or the like during this time, and the lead is regulated and the lead is fed out. By repeating this operation, the core L projects from the core protection member 6 at the tip of the barrel 1 (tip member 5).

However, when the lead is shortened by writing, the lead cannot be held by the chuck 2, and the lead remains between the leading end of the chuck 2 and the lead protecting member 6. This remaining core (hereinafter, referred to as “remaining core”) L
Is only lightly held by the detent member S, so that the writing feeling deteriorates. Therefore, the residual core is generally extruded and discharged by a subsequent core or pulled out by a finger or the like and discarded. Further, when the remnant is removed from the detent member S, the above-described phenomenon is remarkably observed.
In some cases, the core dropped due to its own weight.

[0004] Therefore, in order to make effective use of this residual core, proposals have been made for a core protecting member. For example,
An elastic thin film made of rubber or the like is integrally laminated on the inner surface of the core protecting member, and the elastic thin film increases the frictional resistance with the residual core and prevents the residual core from falling due to its own weight (Japanese Utility Model Publication No. 58-3295).
No. 9) and a method in which a projection is formed on the inner surface of the lead protection member, and the projection is cut into the surface of the residual core to prevent the residual core from falling due to its own weight (Japanese Patent Application Laid-Open No. 56-18898, No. 58-203099).

[0005]

However, these prior art lead protection members have various problems. The former is
After press-filling molten synthetic resin or rubber using a mold, it is cooled to form an elastic thin film on the inner surface of the core protection member. There has been a problem of manufacturing variation such that it becomes impossible to press-fit resin or rubber. Further, when using a mechanical pencil having a core protection member in which an elastic thin film is integrally laminated on the inner surface, when writing on a sheet of paper in a state of a residual core,
There was a problem that wobbling of the residual core occurred at the tip of the lead protection member, and there was a sense of discomfort during writing. This is due to the elastic force of the elastic thin film holding the residual core. That is, the inner surface of the lead protecting member is made of an elastic thin film, and even when the lead is inserted, the elastic force of the thin film is maintained so as to prevent the lead from falling under its own weight. The compression of the elastic thin film causes the user to feel the wobble of the core. The problem of wobbling of the core can be solved even if the pressure for holding the core (hereinafter referred to as “core holding force”) is increased by increasing the thickness of the tip of the core protecting member of the elastic thin film. I could not do it. The elastic thin film is made of resin such as silicone and rubber, and has excellent chemical resistance, heat resistance, and cold resistance.However, it has low resistance to non-polar organic compounds such as gasoline, toluene, and liquid paraffin. Absorbs and swells. on the other hand,
Liquid paraffin, mineral oil,
Oils such as animal oils and vegetable oils are impregnated. When non-polar organic compounds contained in these oils are absorbed by the elastic thin film, the elastic thin film swells and the core holding force increases, making it difficult for the core to come out. was there.

[0006] In the latter, in order to prevent projections from penetrating into the remnant core and prevent falling during remnant writing, the surface of the remnant is scratched by the projections and the strength of the fine core is significantly impaired. There was a problem.

The present invention provides a mechanical pencil which can effectively use the residual core without impairing the core strength. Further, there is no sharpness of the residual core at the time of writing and a sharp pencil which does not increase the core holding force. An object of the present invention is to provide a method for manufacturing a lead protecting member of a pencil.

[0008]

According to the present invention, there is provided a mechanical pencil, wherein a lead is extended from a lead protecting member disposed at a tip of the barrel by moving forward and backward a lead feeding mechanism disposed in the barrel. Is a mechanical pencil in which a part of the resin filled in the lead protection member is removed by a laser beam to form a hole in the longitudinal direction, and the inner face of the hole in the longitudinal direction holds the lead lightly. According to a first aspect, in a mechanical pencil in which a lead is extended from a lead protecting member disposed at a tip of the barrel by moving forward and backward a lead feeding mechanism disposed in the barrel, the lead protecting member is made of resin. A mechanical pencil, which has a metal coated on at least the outer side of the tube and which holds the core lightly by the inner surface of the resin tube, is a second essential feature. In a mechanical pencil in which a lead is extended from a lead protecting member disposed at the tip of the barrel by retracting a lead feeding mechanism disposed in the barrel, the lead protecting member is provided at least outside the resin tube. A third aspect of the present invention is a mechanical pencil in which a conductive film is formed and a metal is coated on the conductive film, and a mechanical pencil that holds the core lightly by the inner surface of the resin tube is included in the shaft cylinder. In a mechanical pencil in which a core feeding mechanism is arranged and a core protection member having at least a resin layer on the inner surface is arranged at the tip of the barrel, the core protection member is plastically deformed by applying external force from the outside.
A fourth aspect of the present invention is a mechanical pencil characterized in that the inscribed diameter of the tip portion is smaller than the inscribed diameter of the rear part, and manufacture of the lead protection member of the mechanical pencil having at least a resin layer on the inner surface of the lead protection member. The method according to claim 1, wherein the tip of the lead protection member is plastically deformed by applying an external force from the outside, and at least a plastic deformation step of making the inscribed diameter of the tip of the lead protection member smaller than the inscribed diameter of the non-deformed portion is provided. A fifth aspect of the present invention is a method of manufacturing a protection member.

According to the present invention, the core protecting member disposed at the tip of the shaft cylinder has a core holding member for holding the core at least on the inner surface of the core protecting member. However, in the case of a residual core, a mechanical pencil that can effectively use the residual core and that does not impair the strength of the core can be obtained. The core protection member is formed by removing a part of the resin filled in the core protection member with a laser beam to form a hole in the longitudinal direction, or by coating at least the outside of the resin pipe with a metal, or a resin pipe. Since a conductive film is formed at least on the outside and a metal is coated on the conductive film, variations in production are small. Also,
By narrowing the inscribed diameter of the tip, the resin layer is compressed and the resistance to the core increases, and the residual core does not wobble during writing. Further, by partially removing the resin layer at the tip, the thickness of the resin layer is reduced, so that the compression ratio of the resin layer is reduced and the wobble of the residual core can be further reduced. Further, since the leading end of the lead protecting member is narrowed, the visibility of the leading end of the lead at the time of writing can be improved. Furthermore, by using a resin with excellent oil resistance for the elastic resin layer, the swelling of the elastic resin layer due to absorption of non-polar organic compounds contained in the core is suppressed, and the core becomes hard to come out due to an increase in core holding force. Does not occur. In addition, the resin tube in the present invention is used to include a resin pipe.

[0010]

Embodiment 1 FIG. 2 is an example of a longitudinal sectional view of a mechanical pencil in the present invention, and FIG. 3 is an example of a longitudinal sectional view of a main part of the mechanical pencil. 2 and 3, reference numeral 1
Is a barrel of a mechanical pencil, and inside the barrel 1 is
A centering mechanism 4 composed of a chuck 2 such as a split chuck or a ball chuck (a split chuck in the figure) and a chuck fastening member 3 (a ring in the figure, using a ball in the case of a ball chuck) is arranged. are doing. Reference numeral 5 denotes a tip member fixed to the barrel 1.
It may be integral with. Further, a lead protection member 6 is fixed to the tip of the tip member 5. Reference numeral 7 denotes a repelling member such as a coil spring for urging the lead-out mechanism 4 rearward (upward in the drawing). Therefore, the center feeding mechanism 4 can advance and retreat in the longitudinal direction. In the drawing, an example is shown in which the center detent member used in the conventional mechanical pencil is removed, but the center detent member may be disposed behind the core protection member as in the conventional case. The above configuration is the same as the basic configuration of a conventional general rear end knock mechanical pencil. In addition, the present invention is a knock type tip,
It can also be used in mechanical pencils of a conventionally known structure such as a rotary knock type, a side slide type, and a center bending knock type.

The features of the present invention reside in the structure of the lead protection member 6 in a mechanical pencil and its manufacturing method. Although the core holding member 8 for holding the core is formed inside the core protecting member 6, the formation of the core holding member 8 enables the core to be held not only when the core is long but also for the remaining core. it can. The core protection member 6 is formed by a method in which a part of the resin filled in the core protection member is removed by a laser beam to form a hole in the longitudinal direction.

As a specific example of the resin used for the core holding member 8, a reaction curable resin, a thermosetting resin, and a thermoplastic resin can be used. Specific examples thereof include epoxy resin, urethane resin, acrylic melamine resin, acryl-silicone resin, acryl-urethane resin, unsaturated polyester resin, alkyd resin, silicone resin, polyvinyl chloride, polyvinyl acetate, and vinyl chloride-vinyl acetate. Copolymer, vinyl butyral resin, silicone rubber, urethane rubber, ethylene acrylic rubber, epichlorohydrin rubber, acrylic rubber, ethylene propylene rubber, chloroprene rubber, natural rubber, isoprene rubber, chlorinated polyethylene, nitrile rubber, styrene-based elastomer, olefin-based Elastomers, ester elastomers, urethane elastomers and the like can be mentioned. Further, an ultraviolet curable resin can also be used, and specific examples thereof include an acrylate having a terminal acryloyl group as a functional group, a monofunctional monomer of methacrylate,
As the polyfunctional monomer and the photopolymerizable prepolymer, polyester acrylate, epoxy acrylate, polyurethane acrylate, polyether acrylate, melamine acrylate, and alkyd acrylate are used. The monomer is not used alone, but is used in combination with the photopolymerizable prepolymer.
These are used alone or in combination of two or more.

Further, by using a resin having excellent oil resistance, even when a lead core containing a nonpolar organic compound slides in the through hole, the core holding member 8 is less likely to absorb the nonpolar organic compound. As a result, the swelling of the core holding member 8 is reduced. As a result, an increase in the core holding force is suppressed, and the mechanical pencil can be used for a long time. In particular, when a resin having a weight change rate of 10% or less when immersed in liquid paraffin (Cas No. 8012-95-1) at 70 ° C. for 20 days is used, the core holding member 8 hardly swells, and This is preferable because the holding force does not change. When a resin having a weight change of more than 10% when immersed in liquid paraffin at 70 ° C. for 20 days exceeds 10%, the non-polar organic compound contained in the refill core absorbs more into the core holding member 8 and swells. Cannot be suppressed, so that the core holding force increases. Core holding force is 2
If it exceeds 00 g, it becomes difficult to advance the lead by the feeding mechanism, and there is a possibility that the lead may be broken inside or the lead cannot be fed.

Further, these resins may contain a foaming agent or powder. As the foaming agent, a chemical foaming agent, a physical foaming agent, a heat-expandable microcapsule, or the like is used. Specific examples of chemical blowing agents include azo compounds, nitroso compounds, hydrazine derivatives, semicarbazide compounds, azide compounds,
Organic pyrolytic blowing agents such as triazole compounds, organic reactive blowing agents such as isocyanate compounds, inorganic pyrolytic blowing agents such as bicarbonates, carbonates, sulfites and hydrides, sodium bicarbonate and acids , A mixture of hydrogen peroxide and yeast, and an inorganic reactive foaming agent such as a mixture of zinc powder and an acid. Specific examples of the physical blowing agent include butane, pentane, hexane, dichloroethane,
Examples thereof include dichloromethane, chlorofluorocarbon, air, carbon dioxide, and nitrogen gas. Specific examples of heat-expandable microcapsules
Microcapsules and the like using low-boiling hydrocarbons such as isobutane, pentane, petroleum ether, and hexane as core materials and shells made of a thermoplastic resin made of a copolymer such as vinyldene chloride, acrylonitrile, acrylates, and methacrylates. Can be One or more of these foams may be added. FIG. 4 shows an example in which a foaming agent is included in the resin, and reference numeral 12 indicates a void formed by foaming.

Specific examples of the powder include resin powders such as styrene, nylon, polyolefin, silicon, epoxy and polymethyl methacrylate, and inorganic powders such as silica, alumina and zirconia. In addition, those powders, acrylic, urethane, composite powder coated with an epoxy-based powder coating, etc., furthermore, an automatic mortar,
Examples thereof include those obtained by adsorbing or driving an inorganic powder smaller than the resin powder into the resin powder using a ball mill, a jet mill, an atomizer, a hybridizer, or the like. Further, the shape of the powder is not particularly limited, and a spherical shape, a plate shape, a needle shape, or the like can be used. One or more of these powders may be added. Also, by adding a powder having a melting point higher than the melting point of the resin,
When a part of the resin is removed by the laser beam, irregularities due to the powder are formed, and the variation in the core diameter can be further absorbed.
FIG. 5 shows an example in which the powder 13 is included in the resin.

As the material of the core protecting member 6, a metal material such as aluminum or its alloy, copper or its alloy, iron or its alloy, zinc or its alloy, magnesium or its alloy, acrylonitrile-butadiene-styrene copolymer ( ABS), acrylonitrile-styrene copolymer (AS), acrylic resin, polycarbonate,
The material is not particularly limited as long as it can form a pipe shape, such as a thermoplastic resin such as polypropylene, polyethylene, polyester, and polystyrene; a ceramic material such as alumina, zirconia, and clay; and a natural material such as wood.
Alternatively, nickel or chromium, a noble metal, a coating film, a printing pattern, or the like may be formed on the outer wall and / or the inner wall of the core protection member 6 in advance by electroplating, electroless plating, painting, or printing.

Next, the forming method will be described. The method of filling the core protection member 6 with the resin is as follows: normal temperature, normal pressure, heating,
What is necessary is just to fill under pressure, a vacuum state, etc., and it does not specifically limit. Next, a part of the filled resin is removed by a laser beam to form a hole 9 in the longitudinal direction. The laser medium of the laser beam to be used is a material capable of melting and removing the resin by heat or being chemically destroyed. There is no particular limitation as long as it can be (decomposed) and removed. Specific examples thereof include solid lasers such as a ruby laser, a YAG laser, a glass laser, and a calcium tungstate laser;
-Ne laser, Ar laser, Kr laser, CO ₂
Gas laser such as laser, liquid laser such as selenium oxychloride laser, chelated laser, Ga-As laser, Ga-Sb laser, Cd-S laser, Zn
And a semiconductor laser such as a -S laser and an excimer laser. The holes may be formed by a laser processing machine or a laser marker using such a laser medium.

As shown in FIG. 6, the shape of the core holding member 8 is a shape having the same thickness, a tapered shape from the rear end to the tip as shown in FIG. 7, or a shape as shown in FIG. Various shapes, such as a step-like shape from the rear end to the front end, and a core holding member 8 formed only on the inner surface of the front part of the core protecting member 6 as shown in FIG. In this method, as described above, after filling the core protection member 6 with the resin to be the core holding member 8, a part of the resin is removed by a laser beam to form a hole 9 in the longitudinal direction. There is a tip member 5
When the core protection member 6 is formed separately from the shaft cylinder 1, the core protection member 6 is attached to the tip of the tip member 5 by press-fitting or insert molding, and then the core protection member 6 is filled with resin and a part of the resin is removed by a laser beam. May be done. Further, the extended core is disposed on the inner surface of the hole 9 of the core holding member 8 of the core protecting member 6. At this time, the core needs to be held lightly by the inner surface of the hole 9 of the core holding member 8. Therefore, the core holding member 8 needs to have elasticity in the radial direction. Therefore, if the resin used for the core holding member 8 does not have elasticity in the radial direction, it is necessary to add an additive to impart elasticity. Core holding member 8
As long as the residual core does not drop by its own weight, it is 10 g in the lead passing direction.
It is preferable to set the weight to 100 g. In addition, when the core holding force is 35 g to 100 g, an effect that the rotation of the core that occurs during writing with the remaining core can be suppressed can be expected. The cross-sectional shape of the hole 9 may be various shapes such as a circular shape, an elliptical shape, a polygonal shape, a petal-shaped inner surface, and a slit or rib formed in the inner surface in a longitudinal direction. .

Embodiment 1-1 Next, an example of a mechanical pencil in Embodiment 1 will be described in detail. Outer diameter 1.07mm, inner diameter 0.76mm, length 6.0
After barrel polishing a stainless steel pipe having a diameter of 2 mm, the solvent was degreased. Next, use silicone resin (GE Toshiba Silicone Co., Ltd.)
TSE3221) was press-filled into the stainless steel pipe. Then, it was cured at 150 ° C. for 30 minutes. Next, CO ₂ laser processing machine (Mitsubishi Electric Corporation)
ML5036D, processing table ML2512
HDII, processing lens f7.5 inches, processing nozzle
2.0), a hole was drilled under the conditions of an output of 200 W and a processing time of 0.5 second, and a hole diameter of 0.54
The lead holding member was formed to form a lead protection member as shown in FIG. Next, the tip member of a mechanical pencil (PG305D, manufactured by Pentel Co., Ltd.) is removed, and the core protection member is press-fitted and fixed to another tip member (manufactured by Pentel, Inc., A125). I got a pencil.

Embodiment 1-2 Next, an example of the mechanical pencil in Embodiment 1 will be described in detail. Outer diameter 1.07mm, inner diameter 0.76mm, length 6.0
After barrel polishing a stainless steel pipe having a diameter of 2 mm, the solvent was degreased. Next, 10 wt% of a dedicated catalyst was added to a silicone resin (SE1701W / C, manufactured by Dow Corning Silicone Toray Co., Ltd.), and after stirring, the inside of the pipe was filled under pressure. Then, it was cured at 150 ° C. for 30 minutes. Next, CO ₂ laser marker (Sunks Co., Ltd.)
Spot diameter 0.18m using LP-200
The core holding member having a rear end hole diameter of 0.54 mm and a front end hole diameter of 0.52 mm is formed inside the core protection member by drilling under the conditions of m, output 6 W, scan speed 500 mm / s, and processing time 1 second. 7 was formed.
Next, use a mechanical pencil (A12
5) Remove the tip member and insert another tip member (Pentel Corporation)
This core protection member was press-fitted and fixed to a tip member for A125) to obtain a mechanical pencil.

Embodiment 1-3 Next, an example of the mechanical pencil in Embodiment 1 will be described in detail. Outer diameter 1.06mm, inner diameter 0.77mm, length 6.0
After barrel polishing an iron pipe of mm, the solvent was degreased. Next, degreasing was performed by a known plating pretreatment method, and a 5 μm Ni plating film was formed by electroless plating. Next, urethane resin (LF-105, manufactured by Asahi Glass Co., Ltd.) was filled under pressure into the pipe. Curing was performed under the conditions of normal temperature, humidity of 90%, and 24 hours. Next, using a CO ₂ laser marker (LP-200, manufactured by Sunkus Co., Ltd.), a spot diameter of 0.1
8mm, output 12W, scan speed 500mm /
s, a hole was drilled under the condition of a processing time of 0.3 seconds, a spot diameter of 0.18 mm, an output of 9 W, and a scan speed of 5 were performed.
Drilling is performed under the conditions of 00 mm / s and processing time of 0.3 seconds, and further, drilling is performed under the conditions of a spot diameter of 0.18 mm, output of 6 W, scan speed of 500 mm / s, and processing time of 0.3 seconds to protect the core. Rear end hole diameter 0.54m inside the member
m, a lead holding member having an intermediate hole diameter of 0.53 mm and a tip hole diameter of 0.52 mm was formed to form a lead protection member as shown in FIG. Next, use a mechanical pencil (Pentel Corporation, P
G505-AD) was removed, and this lead protection member was press-fitted and fixed to another tip member (a PG505-AD tip member manufactured by Pentel Co., Ltd.) to obtain a mechanical pencil.

Embodiment 1-4 Next, an example of the mechanical pencil in Embodiment 1 will be described in detail. Outer diameter 1.07mm, inner diameter 0.76mm, length 6.0
After barrel polishing a stainless steel pipe having a diameter of 2 mm, the solvent was degreased. Next, use silicone resin (GE Toshiba Silicone Co., Ltd.)
A 10% by weight of a foaming agent (Expancel 091DU, manufactured by Nippon Philite Co., Ltd.) was added to TSE3221), dispersed in a mortar, and then pressure-filled into the pipe. Thereafter, foaming and curing were performed at 150 ° C. for 30 minutes. Next, CO ₂ laser processing machine (Mitsubishi Electric Corporation)
ML5036D, processing table ML2512
HDII, processing lens f7.5 inches, processing nozzle
2.0), a hole was drilled under the conditions of an output of 200 W and a processing time of 0.3 second, and a hole diameter of 0.54
The lead holding member was formed to form a lead protection member as shown in FIG. Next, the tip member of a mechanical pencil (PG305D, manufactured by Pentel Co., Ltd.) is removed, and the core protection member is press-fitted and fixed to another tip member (manufactured by Pentel, Inc., A125). I got a pencil.

Embodiment 1-5 Next, an example of the mechanical pencil in Embodiment 1 will be described in detail. Outer diameter 1.06mm, inner diameter 0.77mm, length 6.0
After barrel polishing the brass pipe of mm, the solvent was degreased.
Next, degreased by a known plating pretreatment method, a 5 μm Ni plating film was formed by electroless plating, and then a 0.01 μm Cr plating film was formed by electroplating. Next, a thermosetting acrylic paint (Kansai Paint Co., Ltd.)
3% by weight of silica powder 15 (manufactured by Fuji Silysia Chemical Ltd., Sylysia 770) was added to Magicron 1000, manufactured by Fuji Silysia Chemical Co., Ltd., and the mixture was dispersed by a three-roll mill. Then, it was cured at 180 ° C. for 20 minutes. Next, CO ₂ laser processing machine (Mitsubishi Electric Corporation)
ML5036D, processing table ML2512
HDII, processing lens f7.5 inches, processing nozzle
2.0), a hole was drilled under the conditions of an output of 300 W and a processing time of 1 second, and a hole diameter of 0.54 mm was formed inside the core protecting member.
Was formed to form a lead protection member as shown in FIG. Next, use a mechanical pencil (Pentel Corporation)
PG305D) was removed, and this lead protection member was press-fitted and fixed to another tip member (Pentel Corp., A125 tip member) to obtain a mechanical pencil.

Embodiment 2 In this embodiment, except for the structure of the lead protection member, the embodiment 1
It is omitted because it is the same as. The core protection member in the present embodiment is formed by coating a metal on at least the outside of the resin tube. 10 and FIG.
Is a resin tube which is a core holding member for holding the core,
Denotes a coating metal to be a core protection member. Resin tube 14
Can be formed by various methods such as compression molding, transfer molding, injection molding, extrusion molding, vacuum casting, and the like. Specific examples of the resin include acrylic resin, silicone resin, fluorine resin, and polychlorinated resin. Vinyl, urethane resin, polyurethane resin, polyethylene resin, silicone rubber, urethane rubber, ethylene acrylic rubber, epichlorohydrin rubber, acrylic rubber, ethylene propylene rubber, chloroprene rubber, natural rubber, isoprene rubber, chlorinated polyethylene, nitrile rubber, styrene elastomer Olefin-based elastomer, ester-based elastomer, ester-based elastomer, urethane-based elastomer, and the like. Further, by using a resin having excellent oil resistance, the same effect as in the first embodiment can be obtained. These resins may contain the powder, the foaming agent, the conductive fine particles, and the like described in the first embodiment.

The coating metal 15 formed outside the resin tube 14 serving as the core holding member may be formed by any one of an electroless plating method, a physical vapor deposition method, a chemical vapor deposition method, an electroplating method, and an electroforming method. Are used to form a multi-layer. The material is aluminum, copper, iron, zinc,
Magnesium, chromium, nickel, tin, titanium,
Examples include gold, silver, palladium, platinum, rhodium, ruthenium, and alloys thereof. This coated metal 15
May be formed directly on the resin tube 14 or may be formed after the surface of the resin tube 14 is subjected to a treatment such as activation, hydrophilization, or application of a catalyst. When the coating metal 15 is formed outside the resin tube 14, it is preferable to insert a rod into the resin tube. For the same reason as described in the first embodiment, the resin tube 14 needs to have elasticity in the radial direction. Therefore, when the resin tube 14 has no elasticity in the radial direction, the elasticity is low. It is necessary to add an additive to impart the property. The core holding force of the resin tube 14 may have a core holding force that does not cause the residual core to drop by its own weight, but is preferably set to 10 g to 100 g in the core passing direction. In addition, when the core holding force is 35 g to 100 g, an effect that the rotation of the core that occurs during writing with the remaining core can be suppressed can be expected. The cross-sectional shape of the resin tube 14 is circular, elliptical, polygonal, etc.
There is no particular limitation, as shown in FIG. 12, a petal-shaped inner surface, as shown in FIG. 13, a slit or rib formed in the inner surface in a longitudinal direction, or as shown in FIG.
Various shapes such as a polygonal inner surface can be adopted.

Embodiment 2-1 Next, an example of a mechanical pencil in Embodiment 2 will be described in detail. A circular tube with an outer diameter of 1.0 mm and an inner diameter of 0.55 mm and a length of 100 mm is inserted into a hole of a silicone tube having an outer diameter of 0.50 mm.
A 150 mm long iron bar was inserted. Next, the outside of the silicone tube was hydrophilized by corona discharge treatment. Next, the palladium catalyst was adsorbed to the outside of the silicone tube by a known sensitizer and activator method. Next, using an electroless nickel phosphorus plating solution (BLUE SUMER, manufactured by Nippon Kanigen Co., Ltd.), the solution was treated at a solution temperature of 90 ° C. for 320 minutes to obtain a film thickness of 120 μm.
Was formed by an electroless plating method. Next, after drying, the iron core rod was removed to obtain a nickel-phosphorus pipe having a silicone resin on the inner surface.
Next, the nickel-phosphorus pipe was cut into a length of 6 mm,
A lead protection member was formed. Next, the tip member of the mechanical pencil (PG305D, Pentel Co., Ltd.) is removed, and another tip member (A127 tip member, Pentel Co., Ltd.)
The lead protection member was press-fitted and fixed to obtain a mechanical pencil.

Embodiment 2-2 Next, an example of a mechanical pencil in Embodiment 2 will be described in detail. An iron bar having an outer diameter of 0.54 mm and a length of 100 mm was inserted into a hole of a heat-shrinkable silicone rubber tube having a length of 100 mm (ST-3d4 (0.2) manufactured by Shin-Etsu Chemical Co., Ltd.). Next, by ion plating, 8
A 0 μm titanium nitride film was formed. Next, the iron core rod was removed to obtain a titanium nitride pipe having a silicone resin on the inner surface. Next, the titanium nitride pipe was cut into a length of 6 mm to form a core protection member. Next, the tip member of a mechanical pencil (Pentel Co., Ltd., A125) is removed, and another tip member (Pentel Co., Ltd., A127 tip member) is used.
The lead protection member was press-fitted and fixed to obtain a mechanical pencil.

Embodiment 2-3 Next, an example of the mechanical pencil in Embodiment 2 will be described in detail. An iron bar having an outer diameter of 0.54 mm and a length of 100 mm was inserted into a hole of a conductive microparticle-containing silicone tube having a diameter of 1.0 mm and an inner diameter of 0.55 mm and a length of 100 mm. Next, the outside of the silicone tube was hydrophilized by corona discharge treatment. Next, nickel electroforming solution (Nihon Kagaku Sangyo Co., Ltd., nickel sulfamate high concentration bath)
To stress-free additives (Nippon Chemical Industry Co., Ltd., NS
FE) was added in an amount of 0.5 ml / l, and the liquid composition was such that the stress of the deposited film became a compressive stress, and was 60% at a current density of 10 A / dm ² .
After that, a metal layer (nickel layer) having a thickness of 100 μm was formed by electroforming. Next, after drying, the iron core rod was removed to obtain a nickel pipe having a silicone resin on the inner surface. Next, cut the nickel pipe to a length of 6 mm,
A lead protection member was formed. Next, the tip member of the mechanical pencil (PG305D, Pentel Co., Ltd.) is removed, and another tip member (A127 tip member, Pentel Co., Ltd.)
The lead protection member was press-fitted and fixed to obtain a mechanical pencil.

Embodiment 3 In this embodiment, except for the structure of the lead protecting member, the embodiment 1
It is omitted because it is the same as. The core protection member is formed by a method in which a conductive film is formed at least outside the resin tube, and a metal is coated on the conductive film. 15 and 16, reference numeral 14 denotes a resin tube as a lead holding member for holding a lead, 16 denotes a conductive film, and 15 denotes a coating metal serving as a lead protection member. The resin tube 14 may be formed by various methods such as compression molding, transfer molding, injection molding, extrusion molding, and vacuum casting. Specific examples of the resin include acrylic resin, silicon resin, and fluorine resin. , Polyvinyl chloride, urethane resin, polyurethane resin, polyethylene resin, silicone rubber, urethane rubber, ethylene acrylic rubber, epichlorohydrin rubber, acrylic rubber, ethylene propylene rubber, chloroprene rubber, natural rubber, isoprene rubber, chlorinated polyethylene, nitrile rubber, Examples include styrene-based elastomers, olefin-based elastomers, ester-based elastomers, ester-based elastomers, and urethane-based elastomers. These resins may contain the powder, the foaming agent, or the conductive fine particles described in the first embodiment.

The conductive film 16 formed outside the resin tube 14 serving as the core holding member may be formed by any one of an electroless plating method, a physical vapor deposition method and a chemical vapor deposition method.
It is formed in multiple layers by using more than one kind. The material is
Aluminum, copper, iron, zinc, magnesium, chromium,
Examples include nickel, tin, titanium, gold, silver, palladium, platinum, rhodium, ruthenium, and alloys thereof. The conductive film 16 may be formed directly on the resin tube 14 or may be formed after the surface of the resin tube 14 is subjected to a treatment such as activation, hydrophilization, or application of a catalyst. The conductive film 1 is provided outside the resin tube 14.
When forming 6, a bar is preferably inserted into the resin tube. The same applies when forming the coating metal 15. The method of forming the coating metal 15 formed on the conductive film 16 is as follows. The resin tube on which the conductive film 16 is formed is immersed in an aqueous solution containing metal ions for forming a metal layer to form the immersed conductive film. What is necessary is just to apply a negative potential to the formed resin tube to form a metal. The specific forming method can be variously selected depending on the shape, length, thickness, etc. of the resin tube, and if a metal layer such as an electroplating method, an electroforming method can be formed,
There is no particular limitation.

For the same reason as described in the first embodiment, the resin tube 14 needs to have elasticity in the radial direction.
In the case of having no elasticity in the radial direction, it is necessary to add an additive to impart elasticity. The holding force of the core by the resin tube 14 may be such that the residual core does not drop by its own weight.
It is preferably set to 10 g to 100 g with respect to the core passing direction. In addition, when the core holding force is 35 g to 100 g, an effect that the rotation of the core that occurs during writing with the remaining core can be suppressed can be expected. Note that the cross-sectional shape of the resin tube 14 is not particularly limited, such as a circle, an ellipse, and a polygon. As shown in FIG.
As shown in FIG. 18, various shapes such as those having slits or ribs in the longitudinal direction formed on the inner surface, and those having a polygonal inner surface as shown in FIG. 19 can be adopted.

Embodiment 3-1 Next, an example of a mechanical pencil in Embodiment 3 will be described in detail. In a hole of a circular, 100 mm long silicone tube having an outer diameter of 1.0 mm and an inner diameter of 0.55 mm, an outer diameter of 0.54 mm
A 100 mm long iron bar was inserted. Next, the outside of the silicone tube was hydrophilized by corona discharge treatment. Next, the palladium catalyst was adsorbed to the outside of the silicone tube by a known sensitizer and activator method. Next, using an electroless nickel phosphorus plating solution (BLUE SUMER, manufactured by Nippon Kanigen Co., Ltd.), a treatment is performed at a solution temperature of 90 ° C. for 1 minute to form a conductive film having a thickness of 0.3 μm by an electroless plating method. did. Thereafter, 0.5 ml / l of a stress-free additive (NSF-E, manufactured by Nippon Kagaku Sangyo Co., Ltd.) was added to a nickel electroforming solution (high concentration bath of nickel sulfamate, manufactured by Nippon Kagaku Sangyo Co., Ltd.) to precipitate. A liquid composition where the stress of the film becomes a compressive stress.
/ Dm ² for 60 minutes to form a 100 μm-thick metal layer (nickel layer) by electroforming. Then, after drying,
The iron core rod was removed to obtain a nickel pipe having a silicone resin on the inner surface. Next, the nickel pipe was cut into a length of 6 mm to form a core protection member. Next, the tip member of the mechanical pencil (PG305D, manufactured by Pentel Co., Ltd.) is removed, and another tip member (A127, manufactured by Pentel Co., Ltd.) is removed.
This core protection member was press-fitted and fixed to a tip member)) to obtain a mechanical pencil.

Embodiment 3-2 Next, an example of a mechanical pencil in Embodiment 3 will be described in detail. An iron rod having an outer diameter of 0.54 mm and a length of 150 mm was inserted into a hole of a heat-shrinkable silicone rubber tube having a length of 150 mm (ST-3d4 (0.2) manufactured by Shin-Etsu Chemical Co., Ltd.). Next, the outside of the heat-shrinkable silicone rubber tube was hydrophilized by corona discharge treatment. Next, the palladium catalyst was adsorbed to the outside of the heat-shrinkable silicone rubber tube by a known sensitizer and activator method. Next, using an electroless nickel phosphorus plating solution (BLUE SUMER, manufactured by Nippon Kanigen Co., Ltd.), a solution temperature of 90% was used.
C. for 5 minutes to form a conductive film having a thickness of 1.0 .mu.m by electroless plating. Then, using an industrial chromium plating solution, a treatment was performed at a current density of 10 A / dm ² to obtain a film thickness of 80 μm.
m metal layer (hard chromium layer) was formed by electroplating. Next, after drying, the iron core rod was removed to obtain a hard chrome pipe having a silicone resin on the inner surface. Next, the hard chrome pipe was cut into a length of 6 mm to form a core protection member. Next, use a mechanical pencil (Pentel Corporation)
A125) was removed, and the lead protection member was press-fitted and fixed to another tip member (a tip member for A127 manufactured by Pentel Co., Ltd.) to obtain a mechanical pencil.

Embodiment 3-3 Next, an example of the mechanical pencil in Embodiment 3 will be described in detail. An iron bar having an outer diameter of 0.54 mm and a length of 100 mm was inserted into a hole of a heat-shrinkable silicone rubber tube having a length of 100 mm (ST-3d4 (0.2) manufactured by Shin-Etsu Chemical Co., Ltd.). Next, a copper film having a thickness of 0.1 μm was formed as a conductive film by an ion plating method. Thereafter, 5 ml / l of a stress-free additive (NSF-E, manufactured by Nippon Chemical Industry Co., Ltd.) was added to a nickel electroforming solution (manufactured by Nippon Chemical Industry Co., Ltd., nickel sulfamate high concentration bath) to form a deposited film. A treatment was performed at a current density of 10 A / dm ² for 60 minutes with a liquid composition in which the stress becomes a tensile stress, and a metal layer (nickel layer) having a thickness of 100 μm was formed by electroforming. Next, after drying, the iron core rod was removed to obtain a nickel pipe having a silicone resin on the inner surface. Next, the nickel pipe was cut into a length of 6 mm to form a core protection member. next,
Remove the tip member of a mechanical pencil (P125, A125), and remove another tip member (A12, A12).
This tip protecting member was press-fitted and fixed to a tip member for 7) to obtain a mechanical pencil.

Embodiment 3-4 Next, an example of the mechanical pencil in Embodiment 3 will be described in detail. In a hole of a circular, 100 mm long silicone tube having an outer diameter of 1.0 mm and an inner diameter of 0.55 mm, an outer diameter of 0.54 mm
A 100 mm long iron bar was inserted. Next, the outside of the silicone tube was hydrophilized by corona discharge treatment. Next, aminosilane treatment solution (Nihon Unicar Co., Ltd.)
Solution, A1100 1 wt% alcohol solution)
After immersion at 0 ° C. for 10 minutes, drying was performed at 100 ° C. for 60 minutes.
Next, the palladium catalyst was adsorbed to the outside of the silicone tube by a known sensitizer and activator method. Next, using an electroless nickel phosphorus plating solution (BLUE SUMER, manufactured by Nippon Kanigen Co., Ltd.), a treatment is performed at a solution temperature of 90 ° C. for 1 minute to form a conductive film having a thickness of 0.3 μm by an electroless plating method. did. Thereafter, using a nickel electroforming solution (a high concentration bath of nickel sulfamate manufactured by Nippon Chemical Industry Co., Ltd.), a treatment is performed for 120 minutes at a current density of 10 A / dm ² at a liquid composition in which the stress of the deposited film becomes a compressive stress. A metal layer (nickel layer) having a thickness of 150 μm was formed by electroforming. Next, after drying, the iron core rod was removed to obtain a nickel pipe having a silicone resin on the inner surface. Next, the nickel pipe was cut into a length of 6 mm to form a core protection member. Next, use a mechanical pencil (Pentel Corporation, A
125), the lead protection member was press-fitted and fixed to another tip member (a tip member for A127 manufactured by Pentel Co., Ltd.) to obtain a mechanical pencil.

Embodiment 4 In the lead protecting member of the present invention, a deformed portion can be formed by applying an external force from the outside to cause plastic deformation. 20 and 21 show an example of the lead protection member. A resin layer 17 for holding the core and a metal layer 18 outside the resin layer 17 are formed inside the core protection member. A through hole is formed in the resin layer 17, and the core L
The resin layer 17 slides in the through-hole and is held by the resin layer 17 not only when it is long but also in the residual core. The lead protection member is formed by applying an external force to the tip portion from the outside and plastically deforming the tip protection member. Due to this plastic deformation, the diameter of the through-hole of the resin layer 17 is reduced. Therefore, by narrowing the outer diameter of the tip of the lead protecting member, when the lead passes through the narrowed portion, the resin layer 17 is compressed, the resistance is increased, and the residual core can be prevented from wobbling. Also, the resin layer 17 at the tip of the lead protection member
After a part of the core is removed, the outer diameter of the tip of the lead protecting member is reduced, thereby making it possible to eliminate wobbling of the remaining lead.
Note that the conductive film 16 may be formed between the resin layer 17 and the metal layer 18.

Embodiment 5 A description will be given with reference to FIG. In this embodiment, a part of the resin layer in the core protection member is removed. The method for forming the partially removed portion 20 of the resin layer includes a method of removing with a laser beam (hereinafter, referred to as a removing method 1), a method of cutting (hereinafter, referred to as a removing method 2), and a method of melting (hereinafter, referred to as a removing method).
Removal method 3). Specific examples are:
Various selections can be made depending on the material and shape of the resin layer.
In the first removal method, a laser medium that can be removed by melting a part of the resin layer 17 with heat by a laser beam or a laser medium that can be chemically destroyed (decomposed) and removed is used. For example, solid lasers such as ruby laser, YAG laser, glass laser, calcium tungstate laser, He-Ne laser, Ar laser, Kr
Laser, gas laser such as CO ₂ laser, liquid laser such as selenium oxychloride laser, chelated laser, Ga-As laser, Ga-Sb laser, Cd
Examples thereof include a semiconductor laser such as a —S laser and a Zn—S laser, and an excimer laser, and are not particularly limited. In removal method 2, turning using a mid-boring tool, drilling using a twist drill or half-moon tool,
Examples include reaming and grinding with a grindstone, and are not particularly limited. The removal method 3 includes, for example, a method of deforming the resin layer 17 by pressing a hot iron to deform the resin layer 17, and is not particularly limited. In addition, the resin layer partially removed portion 20
The shape to be removed can be mainly a cylindrical shape, a conical shape, a funnel shape, a polygonal shape or the like, but the shape is not particularly limited.

Embodiment 5-1 FIGS. 23, 24 and 25 show an example. Example 5-1
Is the same as in Example 4 except that the resin layer 1
Example 7 is the same as Example 4 except that a part of the tip of 7 is removed. In this embodiment, the tip of the resin layer 17 is partially removed.
0, so that the elastic force of the resin layer 17 at the tip was
Therefore, the wobble of the core at the tip end portion is smaller than that of the fourth embodiment. When the tip portion of the resin layer 17 is partially removed, for example, the resin layer can be completely removed as shown in FIG. 26, or can be removed in a mortar shape as shown in FIG.

Embodiment 5-2 FIG. 28 shows an example. In this embodiment, the core protection member 6 and the tip member 5 are integrally formed by a metal layer formed outside the resin layer 17. That is, after the metal layer was formed thick, the external appearance and the rear inner surface shape were processed into various shapes by cutting or the like, and the tip of the core protection member 6 was reduced in diameter by drawing.

Embodiment 5-3 FIG. 29 shows an example. In the present embodiment, the inside diameter of the tip portion is reduced by deforming the tip portion of the metal layer 18 of the lead holding member inward by pressing or the like. In this embodiment, first, the metal layer 1 formed by processing the tip of a metal pipe
A method of forming the resin layer 17 in the metal layer 18 after forming the metal layer 8 by pressing or cutting may be employed.

Embodiment 5-4 FIG. 30 shows an example. This embodiment is different from the fourth embodiment in that
The fourth embodiment is the same as the fourth embodiment except that the inner diameter (in this case, the inscribed diameter) is reduced by dividing and deforming at several places instead of narrowing the diameter of the tip portion over the entire circumference.
For processing at a plurality of locations, a method such as press working, punch working, or die-forming can be employed.

Embodiment 6 Next, a method of forming plastic deformation will be described in detail. The method of forming the plastic deformation in this embodiment is based on the drawing method (hereinafter referred to as plastic deformation method 1). The plastic deformation method 1 includes a pipe drawing process using a die having an inner surface having a shape for deforming the tip of the lead protection member. The aperture shape is
There is no particular limitation. A dimethyl-based silicone tube having an outer diameter of 0.86 mm (circular) and an inscribed diameter of 0.52 mm (hexagon) and a length of 500 mm was formed by extrusion, and an iron mandrel was inserted into the hole of the silicone tube. Next, a conductive film (copper thin film) of 0.2 μm was formed on the surface of the silicone tube by an ion plating method. Thereafter, a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.)) 1000 g /
L, nickel chloride 30 g / L, boric acid 35 g / L) and an additive (NSF H-3, manufactured by Nippon Chemical Industry Co., Ltd.)
By adding mL / L, a nickel electroforming solution for forming a metal layer was prepared. Next, the silicone tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, a negative potential was applied under the condition of a current density of 10 A / dm ² , and the treatment was performed for 70 minutes. A metal layer (nickel layer) was formed. Next, dry and then remove the iron mandrel,
This was cut with a cutting cutter. Cutting cutter
GC-320PB manufactured by Disco Co., Ltd. The thickness of the cutter is 0.5 mm or less, and the rotation speed of the cutting cutter is 1500 to 4000 m at the peripheral speed of the cutting cutter.
/ Min.

Since burrs due to the cutting were generated on the end surface of the core protection member after cutting, burrs on the outer peripheral portion of the end surface were removed by barrel polishing or the like. The barrel was wet-typed using a centrifugal flow barrel machine. The barrel polishing stone is polished using a titanium chip together with a compound of water and a surfactant. Next, a method of removing a part of the resin layer 17 at the tip of the lead protecting member will be described. As the removal method, C
Removed by O ₂ laser beam. Laser beam conditions are: focal length 20 mm, light output 15 watts,
Irradiate for 1.5 seconds. This allows 0.5 mm to 1.5
The resin layer 8 can be removed at a depth of mm.
Reference number 9). Next, a manufacturing method for making the inscribed diameter of the distal end portion smaller than the inscribed diameter of the rear portion by applying an external force from the outside and performing plastic deformation will be described with reference to FIGS. 31, 32, and 33. FIG. The deformation is performed by drawing with a die 21. The material of the die 21 is a cemented carbide. The inner surface shape 22 of the die 21 may be a shape that is drawn down by a gentle curve as in a general pipe drawing shape, or may be a tapered shape. A mandrel 23 and a dispensing pipe 24 are arranged inside the die 21. The mandrel 23 is inserted into the core protection member when the core protection member tip is drawn, and the inner diameter of the core protection member tip is reduced to be smaller than the target tip hole inner diameter due to the variation in the thickness of the metal layer 18. (See FIG. 34). Further, the payout pipe 24 is disposed for the purpose of separating the core protecting member from the die 21 when the core protecting member is cut into the die after drawing (see FIG. 33). Dice 24
Is set on the press machine, and the lead protection member 6 is set on the work receiving table 25 arranged in the axial direction of the die 21 (see FIG. 31). Next, the die set 26 is lowered to press the lead protection member 6 (see FIG. 32). After lowering the dimensions, the die set 26 is raised (see FIG. 33). Also,
The positional relationship between the work support 25 and the die set 26 is not limited to the vertical direction. By squeezing the end of the core protecting member by the above series of steps, the tip of the metal layer 18 is deformed to reduce the inscribed diameter, thereby not only preventing the residual core from dropping by its own weight, but also reducing the time of writing. Form a lead protection member of a mechanical pencil that does not generate a feeling of wobbling of the residual core,
A core protection member having a silicone resin layer on the inner surface and having a tip portion plastically deformed (see reference numeral 19 in FIG. 33) was obtained (see FIG. 33).

Embodiment 7 The method of forming plastic deformation in this embodiment is based on a method of deforming by pressing a bearing or the like (hereinafter referred to as plastic deformation method 2). In the plastic deformation method 2, several bearings each having an outer peripheral surface formed in a shape to be deformed at the tip of the core protection member are radially arranged in several axes, and gradually rotated around the center of the bearing in which several are arranged while rotating the core protection member. To deform the tip of the core protection member by pressing against the core protection member, or by gradually pressing a bearing or the like having a shape that rotates the core protection member and deforms the tip of the core protection member from one side. There is a method of deforming the tip, and the like is not particularly limited. The core protection member may be fixed and the bearing side may be rotated. Fluoro-dimethyl copolymerized silicone rubber (XE24-, manufactured by GE Toshiba Silicone Co., Ltd.)
A1680), the outer diameter is 0.90 mm (circular),
A fluoro-dimethyl copolymer silicone tube having an inner diameter of 0.53 mm (circle) and a length of 500 mm was formed by extrusion, and a mandrel made of an iron alloy was inserted into the hole of the silicone tube. Next, a conductive film (copper thin film) of 0.5 μm was formed on the surface of the silicone tube by an ion plating method. Then, nickel electroforming liquid (60%
Nickel sulfamate solution (Nippon Kagaku Sangyo Co., Ltd.)
1000 g / L, nickel chloride 30 g / L, boric acid 35
g / L) and additives (NSF H, manufactured by Nippon Chemical Industry Co., Ltd.)
-2) was added at 10 mL / L to prepare a nickel electroforming solution for forming a metal layer. Next, the silicone tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, and a negative potential was applied under the condition of a current density of 10 A / dm ² , and a treatment was performed for 70 minutes. Was formed. Next, it dried and, after that, the iron alloy mandrel was removed. The cutting method and deburring are the same as in the sixth embodiment.

Part of the silicone tube was removed by fixing the lead protecting member to a rotating shaft, rotating it, and cutting and removing it by boring. Note that the core protection member may be fixed by rotating the center boring tool. Next, a manufacturing method for making the inscribed diameter of the distal end portion smaller than the inscribed diameter of the rear portion by applying an external force from the outside to plastically deform is shown in FIG. 34, FIG. 35, FIG.
6 will be described. The deformation is performed by pressing a bearing 27 having a shape (see FIG. 34, reference numeral 22) formed at the tip to deform. Two or three bearings 27 are radially arranged with respect to the axis of the rotating shaft 28 and are rotatably fixed by a bearing fixing member 29. The bearing set 30 to which the bearing 27 is attached is attached to a rotating spindle, motor, or the like.

The mandrel 23 is inserted into the core protecting member when the leading end of the core protecting member is drawn as in the sixth embodiment.
The purpose is to prevent the inner diameter from being narrowed to be smaller than the inner diameter of the target end hole due to the variation in the thickness of the metal layer 18. The lead protection member is set on the work receiving base 25, and the bearing set 30 is mounted and arranged on a motor or the like that rotates on an extension of the axis of the lead protection member (see FIG. 34).
By pressing the end of the core protection member by pressing against the core protection member while rotating the bearing set 30 by a motor or the like, the tip of the metal layer 18 is deformed (see FIG. 35). After the various dimensions are lowered, the bearing set 30 is raised (see FIG. 36). Also,
The positional relationship between the work support 25 and the bearing set 30 is not limited to the vertical direction. By narrowing the inscribed diameter by the above series of steps, not only preventing the dead weight of the residual core from falling, but also forming a lead protection member of a mechanical pencil that does not generate a feeling of wobbling of the residual core when writing, silicone resin on the inner surface A core protection member having a layer and having its tip portion plastically deformed (see reference numeral 19 in FIG. 36) was obtained (see FIG. 36).

Embodiment 8 The method of forming the plastic deformation in this embodiment is by punching in which a part of the tip portion is deformed with a punch or the like (hereinafter referred to as plastic deformation method 3). The plastic deformation method 3 includes a punching process in which a part of the outer peripheral portion is deformed at several places from the side surface of the tip end portion of the core protecting member by a punch. The shape of the tip of the punch is not particularly limited.

Outer diameter φ 0.92 mm (circular), inner diameter φ
An iron alloy mandrel was inserted into a hole of a 0.51 mm (pentagonal), 6 mm long methylfluoroalkyl-based silicone tube (fluorosilicone tube). Next, a conductive film (copper thin film) of 0.2 μm was formed on the surface of the silicone tube by an ion plating method. afterwards,
Additives (Nippon Kagaku Sangyo Co., Ltd., NSF-) with nickel electroforming solution (60% nickel sulfamate solution (Nippon Kagaku Sangyo Co., Ltd.) 1000 g / L, nickel chloride 30 g / L, boric acid 35 g / L) E) was added at 5 mL / L to prepare a nickel electroforming solution for forming a metal layer. Next, a silicone tube (fluorosilicone tube) on which a conductive film is formed is immersed in the nickel electroforming solution for forming a metal layer,
At a current density of 10 A / dm ² , a negative potential is applied,
After that, a metal layer (nickel layer) having a thickness of 100 μm was formed. Next, it dried and, after that, the iron alloy mandrel was removed. As a method for partially removing the silicone tube, a method was used in which a hot iron having a removed shape was heated to the thermal deformation temperature of the silicone and pressed to deform the silicone to obtain various shapes.

Next, a manufacturing method for making the inscribed diameter of the tip portion smaller than the inscribed diameter of the rear portion by applying an external force from the outside and plastically deforming will be described with reference to FIGS. 37, 38 and 39. In the deformation, a punch 31 is punched at several locations on the outer periphery of the tip end by the punch 31. The punch 3 is formed by deforming the tip (see reference numeral 22 in FIG. 37).
Pressing 1 to deform it. The punch 31 may divide one punch into several punches, or may arrange the punches radially and punch them simultaneously. The direction of the punch is not specified. FIG.
Is an example in which the inscribed diameter is narrowed by being divided into several places and deformed. Further, similarly to the sixth and seventh embodiments, when the leading end of the core protecting member is drawn, it is possible to prevent the inner diameter from being reduced to be smaller than the inner diameter of the target tip hole due to the variation in the thickness of the metal layer 18 and In order to improve the accuracy of the diameter of the inscribed hole at the distal end, the punch may be punched with the mandrel inserted. The shape to be deformed is not limited to the illustrated shape. The method of deformation is not limited to punching, but may be pressing or dies.

Example 9 An outer diameter φ 0.92 m was obtained by using a silicone rubber obtained by mixing a methylfluoroalkyl silicone rubber (fluorosilicone) and a dimethyl silicone rubber at a ratio of 1: 1.
A fluoro-dimethyl mixed silicone tube having a length of 500 mm and a diameter of 0.51 mm (pentagon) with an inscribed circle diameter of 0.5 m (circle) was formed by extrusion. A rod made of an iron alloy was inserted into the hole of the silicone tube. Next, a conductive film (copper thin film) of 0.2 μm was formed on the surface of the silicone tube by an ion plating method. Thereafter, a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.)) 1000 g / L, nickel chloride 30 g
/ L, 35 g / L of boric acid) and 5 mL / L of an additive (NSF-E, manufactured by Nippon Chemical Industry Co., Ltd.) to prepare a nickel electroforming solution for forming a metal layer. Next, the fluoro-dimethyl mixed silicone tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, and the current density was 10%.
A negative potential is applied under the condition of A / dm ^{2 and} the treatment is performed for 60 minutes.
A metal layer (nickel layer) having a thickness of 100 μm was formed. Next, it dried and, after that, the iron alloy mandrel was removed. Cutting, deburring, silicone removal, and drawing may be performed by any of the methods of Examples 5, 6, 7, and 8. The silicone resin layer is provided on the inner surface, and the tip is plastically deformed. A lead protection member was obtained.

Example 10 Outer diameter φ 0.86 mm (circular), inner diameter φ 0.52 mm
(Hexagonal), a dimethyl-based silicone tube having a length of 500 mm was formed by extrusion, and an iron mandrel was inserted into a hole of the silicone tube. Next, the outside of the silicone tube was hydrophilized by corona discharge treatment. Next, the palladium catalyst was adsorbed outside the silicone tube by a known sensitizer and activator method. Next, electroless nickel plating solution (BLUE
SUMER (manufactured by Nippon Kanigen Co., Ltd.) diluted 5 times with ion-exchanged water) and treated at a liquid temperature of 90 ° C. for 1 minute to form a film having a film thickness of 0.2
A μm conductive film (Ni—P alloy thin film) was formed. Then, an additive (manufactured by Nippon Chemical Industry Co., Ltd.) was added to a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.) 1000 g / L, nickel chloride 30 g / L, boric acid 35 g / L). NSF H-3) was added at 10 mL / L to prepare a nickel electroforming solution for forming a metal layer. next,
A dimethyl-based silicone tube having a conductive film formed thereon is immersed in the nickel electroforming solution for forming a metal layer, and the current density is set to 1%.
A negative potential was applied under the conditions of 0 A / dm ^{2 and} the treatment was performed for 70 minutes to form a metal layer (nickel layer) having a thickness of 120 μm. Next, it was dried and then the iron mandrel was removed.
Cutting, deburring, silicone removal, and drawing may be performed by any of the methods of Examples 5, 6, 7, and 8. The silicone resin layer is provided on the inner surface, and the tip is plastically deformed. A lead protection member was obtained.

Example 11 Using fluoro-dimethyl copolymerized silicone rubber (XE24-A1680, manufactured by GE Toshiba Silicone Co., Ltd.), an outer diameter of 0.90 mm (circular), an inner diameter of 0.53 mm (circular), and a length of A 500 mm fluoro-dimethyl copolymer silicone tube was formed by extrusion, and a bar made of an iron alloy was inserted into the hole of the silicone tube. next,
The outside of the silicone tube was hydrophilized by plasma treatment. Next, the palladium catalyst was adsorbed to the outside of the silicone tube by a known catalyst method. Next, the silicone tube was placed in an electroless copper plating solution (Chemical copper solution 500A solution (125 Okuno Pharmaceutical Co., Ltd.)
mL / L and a chemical copper solution 500B solution (mixed solution of 125 mL / L manufactured by Okuno Pharmaceutical Co., Ltd.)
Then, a conductive film (copper thin film) having a thickness of 0.5 μm was formed. Thereafter, a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.)) 10
00 g / L, nickel chloride 30 g / L, boric acid 35 g /
L) and additives (NSF H-
2) was added at 10 mL / L to prepare a nickel electroforming solution for forming a metal layer. Next, the fluoro-dimethyl copolymer silicone tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, and a negative potential was applied under the condition of a current density of 10 A / dm ² , followed by treatment for 70 minutes. , Film thickness 120 μm
Was formed. Next, it dried and, after that, the iron alloy core rod was removed. Cutting, deburring,
Silicone removal and drawing may be performed by any of the methods of the fifth, sixth, seventh, and eighth embodiments. A core protection member having a silicone resin layer on the inner surface and plastically deforming the tip is obtained. Was.

Example 12 A bar made of an iron alloy was inserted into a hole of a heat-shrinkable silicone tube having a length of 300 mm (ST-3d4 (0.2) manufactured by Shin-Etsu Chemical Co., Ltd.). Next, a conductive film (copper thin film) having a thickness of 0.2 μm was formed on the surface of the heat-shrinkable silicone tube by an ion plating method. Thereafter, a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.) 1000 g / L, nickel chloride 30 g / L,
Boric acid (35 g / L) and additives (manufactured by Nippon Chemical Industry Co., Ltd.)
NSF-E) was added at 5 mL / L to prepare a nickel electroforming solution for forming a metal layer. Next, the heat-shrinkable silicone tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, and a negative potential was applied at a current density of 10 A / dm ² , and the film was treated for 60 minutes. A metal layer (nickel layer) having a thickness of 100 μm was formed. Next, it dried and, after that, the iron alloy core rod was removed. Cutting, deburring, silicone removal, and drawing may be performed by any of the methods of Examples 5, 6, 7, and 8. The silicone resin layer is provided on the inner surface, and the tip is plastically deformed. A lead protection member was obtained.

Example 13 Outer diameter φ1.0 mm (circular), inner diameter φ0.5 mm (circular)
Then, an iron mandrel was inserted into the hole of the fluororesin tube having a length of 500 mm. Next, a conductive film (copper thin film) having a thickness of 0.2 μm was formed on the surface of the tube by an ion plating method. Thereafter, a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.)) 1000 g /
L, nickel chloride 30 g / L, boric acid 35 g / L) and an additive (NSF-E, manufactured by Nippon Chemical Industry Co., Ltd.) at 5 mL /
L was added to prepare a nickel electroforming solution for forming a metal layer.
Next, the fluororesin tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, and the current density was 10 A /
A negative potential was applied under the conditions of dm ^{2 and} the treatment was performed for 60 minutes to form a metal layer (nickel layer) having a thickness of 100 μm. next,
After drying, the iron alloy core rod was removed. Cutting,
Deburring, silicone removal, and drawing may be performed by any of the methods of the fifth, sixth, seventh, and eighth embodiments.
A core protection member having a fluorine resin layer on the inner surface and having a tip portion plastically deformed was obtained.

Example 14 An acrylic pipe having an outer diameter of 1.0 mm (circular) and an inner diameter of 0.58 mm (circular) and a length of 500 mm was formed by extrusion. Next, the outside of this acrylic pipe was hydrophilized by corona discharge treatment. Next, a palladium catalyst was adsorbed to the outside of the acrylic pipe by a known sensitizer and activator method. Next, a palladium catalyst was adsorbed to the outside of the acrylic pipe by a known catalyst method. Next, 125 mL / L of the electroless copper plating solution (Chemical copper solution 500A solution (manufactured by Okuno Pharmaceutical Co., Ltd.)) and 125 mL / L of chemical copper solution 500B solution (manufactured by Okuno Pharmaceutical Co., Ltd.) The mixture was immersed in a mixed solution) and treated at a liquid temperature of 25 ° C. for 10 minutes to form a conductive film (copper thin film) having a thickness of 0.5 μm. afterwards,
The acrylic pipe on which the conductive film was formed was immersed in a copper electroforming solution (acidic copper sulfate bath), a negative potential was applied under the condition of a current density of 5 A / dm ² , and a 50 μm-thick metal layer (copper layer)
Was formed. Cutting, deburring, silicone removal, and drawing may be performed by any of the methods of Examples 5, 6, 7, and 8. The acrylic resin layer is provided on the inner surface, and the tip is plastically deformed. A lead protection member was obtained.

Example 15 Fluoro-dimethyl copolymerized silicone rubber (XE24-A1680, manufactured by GE Toshiba Silicone Co., Ltd.): Weight change rate 2
% (When immersed in liquid paraffin at 70 ° C. for 20 days, the same applies hereinafter)), an outer diameter of 0.86 mm (circular) and an inscribed diameter of φ
0.52mm (hexagon), 500mm long fluoro-
A dimethyl copolymerized silicone tube was formed by extrusion, and an iron mandrel was inserted into the hole of the silicone tube. Next, a conductive film (copper thin film) was formed on the silicone tube surface by 0.5 μm by ion plating.
Formed. Thereafter, 1000 g of a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.))
/ L, nickel chloride 30 g / L, boric acid 35 g / L) and an additive (NSF H-3, manufactured by Nippon Chemical Industry Co., Ltd.)
0 mL / L was added to prepare a nickel electroforming solution for forming a metal layer. Next, the silicone tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, a negative potential was applied under the condition of a current density of 10 A / dm ² , and the treatment was performed for 70 minutes. A metal layer (nickel layer) was formed. Next, after drying, and after that, after removing the iron mandrel, this was cut with a cutting cutter to obtain a core protection member.
A lead core is passed through the obtained lead protection member, the lead holding force is measured with a digital force gauge (Model DPX-1 manufactured by Imada Co., Ltd.), and after 200 lead leads are passed through the lead protection member, again When the core holding force was measured with a digital force gauge, no increase in the core holding force was confirmed.

Example 16 Fluoro-dimethyl copolymerized silicone rubber (manufactured by GE Toshiba Silicone Co., Ltd., XE24-A1680: weight change rate 2)
%), Outer diameter φ 0.90mm (circular), inner diameter φ
A 0.53-mm (circular) fluoro-dimethyl copolymer silicone tube having a length of 500 mm was formed by extrusion, and a bar made of an iron alloy was inserted into the hole of the silicone tube. Next, a conductive film (copper thin film) was formed on the surface of the silicone tube by 0.5 μm by an ion plating method.
m was formed. Then, a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.)) 1000
g / L, nickel chloride 30 g / L, boric acid 35 g / L)
10 mL / L of an additive (NSF H-2, manufactured by Nippon Chemical Industry Co., Ltd.) was added to the mixture to prepare a nickel electroforming solution for forming a metal layer. Next, in this nickel electroforming solution for forming a metal layer,
Immerse the silicone tube on which the conductive film is formed,
A negative potential was applied under the condition of a current density of 10 A / dm ² , and 70
After that, a metal layer (nickel layer) having a thickness of 120 μm was formed. Next, after drying and further removing the iron alloy mandrel, this was cut with a cutting cutter to obtain a core protection member. A lead core was passed through the obtained lead protection member, the lead holding force was measured with a digital force gauge, and after passing 200 lead leads through the lead protection member, the lead holding force was measured again with a digital force gauge. No increase in holding power was observed.

Example 17 Outer diameter φ 0.92 mm (circular), inscribed diameter φ 0.51 mm
A (pentagonal) mandrel made of an iron alloy was inserted into a hole of a methylfluoroalkyl-based silicone tube (fluorosilicone tube: weight change rate 1%) having a length of 6 mm. next,
A conductive film (copper thin film) of 0.2 μm was formed on the surface of the silicone tube by an ion plating method. Thereafter, an additive (manufactured by Nippon Chemical Industry Co., Ltd.) was added to a nickel electroforming solution (1000 g / L of a 60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.), nickel chloride 30 g / L, boric acid 35 g / L). NSF-E) was added at 5 mL / L,
A nickel electroforming solution for forming a metal layer was prepared. Next, a silicone tube (fluorosilicone tube) on which a conductive film is formed is immersed in the nickel electroforming solution for forming a metal layer, and a negative potential is applied under a condition of a current density of 10 A / dm ² .
The treatment was performed for 60 minutes to form a metal layer (nickel layer) having a thickness of 100 μm. Next, after drying and further removing the iron alloy mandrel, this was cut with a cutting cutter to obtain a core protection member. A lead core was passed through the obtained lead protection member, the lead holding force was measured with a digital force gauge, and after passing 200 lead leads through the lead protection member, the lead holding force was measured again with a digital force gauge. No increase in holding power was observed.

Example 18 Using a silicone rubber (weight change ratio: 8%) in which a methylfluoroalkyl silicone rubber (fluorosilicone) and a dimethyl silicone rubber were mixed at a ratio of 1: 1.
Outer diameter φ0.92mm (circular), inscribed circle diameter φ0.51mm
A (pentagonal), 500-mm-long fluoro-dimethyl mixed silicone tube was formed by extrusion. An iron alloy mandrel was inserted into the hole of the silicone tube.
Next, a conductive film (copper thin film) of 0.2 μm was formed on the surface of the silicone tube by an ion plating method. Thereafter, a nickel electroforming solution (60% nickel sulfamate solution (manufactured by Nippon Chemical Industry Co., Ltd.)) 1000 g / L,
An additive (NSF-E, manufactured by Nippon Chemical Industry Co., Ltd.) was added at 5 mL / L to 30 g / L of nickel chloride and 35 g / L of boric acid to prepare a nickel electroforming solution for forming a metal layer. Next, the fluoro-dimethyl mixed silicone tube on which the conductive film was formed was immersed in the nickel electroforming solution for forming a metal layer, and a negative potential was applied under the condition of a current density of 10 A / dm ² ,
The treatment was performed for 60 minutes to form a metal layer (nickel layer) having a thickness of 100 μm. Next, after drying and further removing the iron alloy mandrel, this was cut with a cutting cutter to obtain a core protection member. A lead core was passed through the obtained lead protection member, the lead holding force was measured with a digital force gauge, and after passing 200 lead leads through the lead protection member, the lead holding force was measured again with a digital force gauge. No increase in holding power was observed.

Comparative Example A commercially available mechanical pencil product (A1 manufactured by Pentel Co., Ltd.)
25, outer diameter 0.9mm, inner diameter 0.61mm, length 6mm
(A stainless steel pipe was used as a core protection member and a detent member was provided).

Examples 1-1 to 1-5 and 2-1 to 2-
Tables 1 and 2 show the results of evaluation of the core holding power of the mechanical pencils obtained in 3, 3-1 to 3-4 and Comparative Examples, and the evaluation of the presence or absence of the residual core falling under its own weight.

The core holding force in the evaluation of the core holding force is a replacement lead for a mechanical pencil (nominal diameter 0.5 (JIS S6
005), HB (Hi-POLYM manufactured by Pentel Co., Ltd.)
ERAin (C255-HB) is inserted into the lead protection member attached to the tip member, is made vertical, grips the tip member, applies a downward force, and applies a load (static friction) when the lead starts moving backward. The load was measured, and each sample was evaluated for 5 samples (5 products in the comparative example), and the average value, the maximum value, and the minimum value were obtained.

The presence / absence of falling of the residual core due to its own weight is determined by cutting the Hi-POLYMER Ain (C255-HB) to a length of 3 mm (remaining core), and using the tip of the core protecting member of each of Examples and Comparative Examples. Then, the rear end of the residual core was connected to the distal end of the succeeding core, and the state of the residual core when it was made vertical was confirmed.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

According to the present invention, there is provided a lead protecting member in which a part of the resin filled in the lead protecting member is removed by a laser beam to form a hole in a longitudinal direction, or at least an outer portion of a resin tube or pipe. Since there is little variation in production, a metal film is coated, or a conductive film is formed at least outside a resin tube or a pipe, and the metal film is coated on the conductive film. Also,
By reducing the inscribed diameter of the leading end of the lead protecting member, the resin layer is compressed and the resistance to the lead is increased, and the wobble of the remaining lead does not occur during writing. Further, by partially removing the resin layer at the leading end of the lead protecting member, the thickness of the resin layer is reduced, so that the compression ratio of the resin layer is reduced, and the wobble of the residual core can be further reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a conventional technique.

FIG. 2 is a longitudinal sectional view of the mechanical pencil of the present invention.

FIG. 3 is a longitudinal sectional view of a main part of the mechanical pencil of the present invention.

FIG. 4 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 5 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 6 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 7 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 8 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 9 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 10 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 11 is a cross-sectional view of the lead protection member of the present invention.

FIG. 12 is a cross-sectional view of the lead protection member of the present invention.

FIG. 13 is a cross-sectional view of the lead protection member of the present invention.

FIG. 14 is a cross-sectional view of the lead protection member of the present invention.

FIG. 15 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 16 is a cross-sectional view of the lead protection member of the present invention.

FIG. 17 is a cross-sectional view of the lead protecting member of the present invention.

FIG. 18 is a cross-sectional view of the lead protecting member of the present invention.

FIG. 19 is a cross-sectional view of the lead protection member of the present invention.

FIG. 20 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 21 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 22 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 23 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 24 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 25 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 26 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 27 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 28 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 29 is a longitudinal sectional view of the lead protecting member of the present invention.

FIG. 30 is a perspective view of a lead protecting member of the present invention.

FIG. 31 is a longitudinal sectional view showing a manufacturing process of the lead protecting member of the present invention.

FIG. 32 is a longitudinal sectional view showing a manufacturing process of the lead protecting member of the present invention.

FIG. 33 is a longitudinal sectional view showing the manufacturing process of the lead protecting member of the present invention.

FIG. 34 is a longitudinal sectional view showing a manufacturing process of the lead protecting member of the present invention.

FIG. 35 is a longitudinal sectional view showing a manufacturing process of the lead protecting member of the present invention.

FIG. 36 is a longitudinal sectional view showing a manufacturing process of the lead protecting member of the present invention.

FIG. 37 is a longitudinal sectional view showing the manufacturing process of the lead protecting member of the present invention.

FIG. 38 is a longitudinal sectional view showing the manufacturing process of the lead protecting member of the present invention.

FIG. 39 is a perspective view of the lead protecting member of the present invention.

[Explanation of symbols]

 L core (remaining core) S detent member 1 barrel 2 chuck 3 chuck fastening member 4 core feeding mechanism 5 leading member 5a stepped portion 6 core protection member 7 resilient member 8 core holding member 9 hole 10 core tank 11 knock 12 gap DESCRIPTION OF SYMBOLS 13 Powder 14 Resin tube (core holding member) 15 Coating metal (core protection member) 16 Conductive film 17 Resin layer (core holding member) 18 Metal layer (core protection member) 19 Deformation part 20 Partial removal part of resin layer DESCRIPTION OF SYMBOLS 21 Dice 22 Shape which deforms the tip 23 Mandrel 24 Dispensing pipe 25 Work pedestal 26 Dice set 27 Bearing 28 Rotating shaft 29 Bearing fixing member 30 Bearing set 31 Punch

 ──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 2000-230193 (P2000-230193) (32) Priority date July 31, 2000 (July 31, 2000) (33) Priority claim country Japan (JP) (72) Inventor Hidetoshi Kodama 4-1-8 Yoshimachi, Soka City, Saitama Prefecture Pentel Co., Ltd. Inside the grass processing plant (72) Inventor Naoto Yoshihara 4-1-8 Yoshimachi, Soka City, Saitama Prefecture Pentel Co., Ltd. Inside the company grass processing plant (72) Inventor Kenichi Kamakura 4-1-8 Yoshimachi, Soka City, Saitama Prefecture Pentel Co., Ltd. Inside the grass processing plant F-term (reference)

Claims (15)

[Claims] 1. A mechanical pencil in which a lead is extended from a lead protecting member disposed at a tip of the barrel by moving forward and backward a lead feeding mechanism disposed in the barrel. A mechanical pencil in which a part of a resin filled in a member is removed by a laser beam to form a hole in a longitudinal direction, and a core is held lightly by an inner surface of the hole in the longitudinal direction. 2. A mechanical pencil, wherein a lead is extended from a lead protecting member disposed at a tip of the barrel by moving forward and backward a lead feeding mechanism disposed in the barrel, wherein the lead protecting member comprises a resin tube. A mechanical pencil coated with a metal at least on an outer side thereof, wherein the inner core of the resin tube holds the core lightly. 3. A mechanical pencil in which a lead is extended from a lead protecting member disposed at the tip of the barrel by moving forward and backward a lead feeding mechanism disposed in the barrel, wherein the lead protecting member is a resin tube. A mechanical pencil formed by forming a conductive film at least on an outer side thereof and coating the conductive film with a metal, wherein the core is lightly held by the inner surface of the resin tube. 4. In a mechanical pencil in which a lead-out mechanism is disposed in a barrel and a lead protection member having at least a resin layer on the inner surface is placed at the tip of the barrel, the lead protection member applies an external force from the outside. A mechanical pencil characterized in that the inscribed diameter at the front end is made smaller than the inscribed diameter at the rear end by plastic deformation. 5. The mechanical pencil according to claim 4, wherein the lead protecting member is obtained by partially removing a resin layer at a tip portion before plastic deformation. 6. The mechanical pencil according to claim 2, wherein the shape of the bore in the cross section of the resin tube is irregular. 7. The mechanical pencil according to claim 1, wherein the resin has excellent oil resistance. 8. The resin having excellent oil resistance has a weight change rate of 10% when immersed in liquid paraffin (at 70 ° C. for 20 days).
% Of the resin. 9. The mechanical pencil according to claim 7, wherein the resin having excellent oil resistance is silicone rubber. 10. The silicone rubber according to claim 9, wherein the silicone rubber is a fluoro-dimethyl copolymerized silicone rubber.
Mechanical pencil described in 1. 11. The mechanical pencil according to claim 1, wherein the residual core does not fall by its own weight. 12. A wick holding force of 10 g with respect to a wick passing direction.
The mechanical pencil according to any one of claims 1 to 11, which weighs from 1 to 100 g. 13. A wick holding force of 35 g with respect to the wick passing direction.
The mechanical pencil according to any one of claims 1 to 11, which weighs from 1 to 100 g. 14. A method for manufacturing a lead protection member of a mechanical pencil having at least a resin layer on an inner surface of the lead protection member, wherein the tip of the lead protection member is plastically deformed by applying an external force from the outside, and A method for manufacturing a lead protecting member of a mechanical pencil, the method including at least a plastic deformation step of making a contact diameter smaller than an inscribed diameter of a non-deformed portion. 15. The method for manufacturing a lead protecting member of a mechanical pencil according to claim 14, further comprising a step of partially removing a resin layer at a tip portion of the lead protecting member before the plastic deformation step.