Citizen Watch Company, Ltd.

Ryota Koike

Takashi Toida

Yukio Miya

Osamu Sugiyama

Toshiichi Sekine

Yuji Fukazawa

Sosaku Kimura

Kunihiko Kokubo

A hard carbon film ( ) is formed directly or through an intermediate layer for enhancing adhesion over an inner surface ( ) of a guide bush ( ) for holding a workpiece ( ) rotatably and axially slidable on an automatic lathe at a position near a cutting tool, to be in sliding contact with the workpiece ( ) or directly or through an intermediate layer for enhancing adhesion on the surface of a superhard lining fixed to the inner surface ( ). The guide bush ( ) has remarkably enhanced durability and prevents damaging the workpiece ( ) and seizing that makes a machining operation impossible even when the guide bush ( ) is used for an extended period of time and when the automatic lathe operates for heavy machining. The hard carbon film ( ) having satisfactory adhesion to the inner surface ( ) can be efficiently formed in a uniform thickness over the inner surface ( ) by placing the guide bush ( ) in a vacuum vessel, extending an auxiliary electrode in the center bore of the guide bush ) and producing a plasma of a gas containing carbon.

Guide bush and method of forming hard carbon film over the inner surface of the guide bush

The invention provides a guide bush wherein a cemented carbide alloy containing at least cobalt is provided on an inner surface thereof for holding a workpiece rotatably and slidably in the longitudinal axial direction thereof in close proximity of a cutting tool, and a DLC film is formed over the cemented carbide alloy, cobalt being removed from the surface of the cemented carbide alloy, adjoining the DLC film. By forming the DLC film on the surface of the cemented carbide alloy from which cobalt has been removed, with an intermediate layer formed therebetween, adhesiveness of the DLC film against the cemented carbide alloy fixedly attached to the inner surface of the guide bush is further enhanced.

Guide bush and method of forming diamond-like carbon film over the guide bush

The invention provides a guide bush wherein a cemented carbide alloy containing at least cobalt is provided on an inner surface thereof for holding a workpiece rotatably and slidably in the longitudinal axial direction thereof in close proximity of a cutting tool, and a DLC film is formed over the cemented carbide alloy, cobalt being removed from the surface of the cemented carbide alloy, adjoining the DLC film. By forming the DLC film,on the surface of the cemented carbide alloy,from which cobalt has been removed, with an intermediate layer formed therebetween, adhesiveness of the DLC film against the cemented carbide alloy fixedly attached to the inner surface of the guide bush is further enhanced.

The present invention relates to a method of forming an intermediate film and a hard carbon film over the inner surface of a cylindrical member having a bore, such as a bushing or a cylinder, with the hard carbon film being formed on the intermediate film with a uniform thickness, greatly enhancing of abrasion resistance of the inner surface. The cylindrical member is placed in a vacuum vessel, an auxiliary electrode of an intermediate film forming material, such as a titanium-silicon alloy or the like, is inserted in the bore of the cylindrical member, a sputtering gas is supplied into the vacuum vessel, a voltage is applied to the auxiliary electrode to produce a plasma around the auxiliary electrode in order that the intermediate film forming material is sputtered from the auxiliary electrode and an intermediate film is formed over the inner surface of the cylindrical member. Subsequently, a gas containing carbon, such as methane gas or the like, is supplied into the vacuum vessel, and a voltage is applied to the cylindrical member to produce a plasma in the vacuum vessel in order that a hard carbon film (DLC film) is formed on the previously formed intermediate film over the inner surface of the cylindrical member.

Method of forming films over inner surface of cylindrical member

A hard carbon film is formed over an inner surface of a guide bush by fixing an auxiliary electrode support member for supporting an auxiliary electrode of a jig for forming a film in a center bore of the guide bush by an auxiliary electrode insulation member, disposing an auxiliary electrode in alignment with the axis of the center bore so as to face the inner surface, disposing legs, and a first electrode plate, a second electrode plate, and the insulation member which are fixed to the legs are placed on the bottom of a vacuum vessel placing the guide bush on the first electrode plate contacted electrically with a power source, while the projection of the auxiliary electrode support member projecting out of the auxiliary electrode insulation member is contacted electrically with the second electrode plate. The auxiliary electrode is grounded through the auxiliary electrode support member, the second electrode plate, the legs, and the vacuum vessel, a gas containing carbon is introduced into the vacuum vessel after evacuating the vacuum vessel, and a plasma is produced in the vacuum vessel by supplying electric power to the guide bush through the first electrode plate from the power source.

Jig for forming hard carbon film over inner surface of guide bush using

The present invention relates to a method of forming an intermediate film and a hard cabon film over the inner surface of a cylindrical member having a bore, such as a bushing or a cylinder, with the hard carbon film being formed on the intermediate film with a uniform thickness, greatly enhancing of abrasion resistance of the inner surface. The cylindrical member is placed in a vacuum vessel, an auxiliary electrode of an intermediate film forming material, such as a titanium-silicon alloy or the like, is inserted in the bore of the cylindrical member, a sputtering gas is supplied into the vacuum vessel, a voltage is applied to the auxiliary electrode to produce a plasma around the auxiliary electrode in order that the intermediate film forming material is sputtered from the auxiliary electrode and an intermediate film is formed over the inner surface of the cylindrical member. Subsequently, a gas containing carbon, such as methane gas or the like, is supplied into the vacuum vessel, and a voltage is applied to the cylindrical member to produce a plasma in the vacuum vessel in order that a hard carbon film (DLC film) is formed on the previously formed intermediate film over the inner surface of the cylindrical member.

A hard carbon film is formed over an inner surface of a guide bush including the steps of fixing an auxiliary electrode support member for supporting an auxiliary electrode of a jig for forming a film in a center bore of the guide bush by an auxiliary electrode insulation member, disposing an auxiliary electrode in alignment with the axis of the center bore so as to face the inner surface, disposing legs, and a first electrode plate, a second electrode plate, and the insulation member which are fixed to the legs are placed on the bottom of a vacuum vessel placing the guide bush on the first electrode plate contacted electrically with a power source, while the projection of the auxiliary electrode support member projecting out of the auxiliary electrode insulation member is contacted electrically with the second electrode plate. The auxiliary electrode is grounded through the auxiliary electrode support member, the second electrode plate, the legs, and the vacuum vessel, a gas containing carbon is introduced into the vacuum vessel after evacuating the vacuum vessel, and a plasma is produced in the vacuum vessel by supplying electric power to the guide bush through the first electrode plate from the power source.

Method of forming a hard carbon film over an inner surface of a guide

A hard carbon film is formed over an inner surface of a guide bush by the steps of disposing the guide bush in a vacuum vessel, inserting an electrode into a center bore of the guide bush and applying a positive current to the electrode, introducing a gas, containing carbon, through a gas inlet port into the vacuum chamber after evacuating the vacuum vessel, and producing a plasma in the vacuum vessel to form a hard carbon film of hydrogenated amorphous carbon over the inner surface of the guide bush by a plasma CVD method.

Method of forming a hard carbon film over the inner surface of a guide

A method of forming films over an insulating material is provided whereby an underlayer film having electric conductivity is formed on the surface of the insulating material constituting a base member, and a hard carbon film is formed over the underlayer film so that the surface electrical resistance value of the hard carbon film can be controlled so as not to cause the surface thereof to be charged with static electricity by varying an electrical resistance value of the underlayer film. In the case where the underlayer film is formed of a metal film composed of titanium, chromium, tungsten, or the like, the resistance value thereof can be changed by varying the thickness of the metal film. In the case where the underlayer film is formed of a semiconductor film composed of silicon, germanium, or the like, the resistance value thereof can be changed by varying the thickness of the semiconductor film, or the concentration of an impurity added thereto.

Method of forming films over insulating material

Guide bush and method of forming film over guide bush

Method of forming hard carbon film over the inner surface of guide bush

Method of removing hard carbon film formed on inner circumferential

The present invention relates to a method of forming a two-layer intermediate film over the inner surface of a cylindrical member, such as a bushing or a cylinder, with a DLC film being formed on the intermediate film with a uniform thickness by using an auxiliary electrode, greatly enhancing of abrasion resistance of the inner surface. The cylindrical member is placed in a vacuum vessel, an auxiliary electrode of a first intermediate film forming material is inserted in the bore of the cylindrical member, a sputtering gas is supplied into the vacuum vessel, keep the auxiliary electrode at ground potential or a negative DC voltage is applied to the auxiliary electrode to produce a plasma around the auxiliary electrode in order that a first intermediate film is formed over the inner surface of the cylindrical member. A gas containing silicon or germanium is supplied into the vacuum vessel in which the cylindrical member and the auxiliary electrode are disposed, and a voltage is applied to the cylindrical member to produce a plasma, thereby forming a second intermediate film on the first intermediate film. Subsequently, a gas containing carbon, such as methane or the like, is supplied into the vacuum vessel in which the cylindrical member and the auxiliary electrode are disposed, and a voltage is applied to the cylindrical member to produce a plasma in the vacuum vessel in order that the DLC film is formed on the previously formed second intermediate film over the inner surface of the cylindrical member.

Method of forming DLC films over inner surface of cylindrical member

A hard carbon film is formed directly or through an intermediate layer for enhancing adhesion over an inner surface of a guide bush in such a manner that the thickness of the inner surface at the portion near an open end is greater than that at the inner portion thereof, wherein the inner surface is in sliding contact with a workpiece and the guide bush is mounted on an automatic lathe for holding the workpiece rotatably and slidably in the axial direction near a cutting tool. Accordingly, the guide bush is disposed in a vacuum vessel to form a hard carbon film of a hydrogenated amorphous carbon over the inner surface of the guide bush by a plasma CVD method. At this time, a rodlike auxiliary electrode provided with a stepped portion having an extremity which is smaller than another portion or a rodlike auxiliary electrode provided with a tapered portion having an extremity is inserted into the center bore forming the inner surface of the guide bush in such a manner that the extremity of the tapered portion is positioned near the open end of the inner surface of the guide bush, and the auxiliary electrode is grounded or a positive DC current is applied to the auxiliary electrode.

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Tokorozawa, Japan

Ryota Koike