Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A hard carbon film (15) is formed directly or through an intermediate layer for enhancing adhesion over an inner surface (11b) and over a portion (11h.sub.1) of an end face (11h) of a guide bush 11 adjacent to the end of the inner surface for holding a workpiece (51) rotatably and axially slidable on an automatic lathe at a position near a cutting tool, to be in sliding contact with the workpiece (51) or directly or through an intermediate layer for enhancing adhesion on the surface of a superhard lining fixed to the inner surface (11b) in a plasma CVD process employing an auxiliary electrode and a dummy member. Thereby, the guide bush (11) has remarkably enhanced durability and prevents seizing that makes a machining operation impossible, even when the guide bush (11) is used for an extended period of time and when the automatic lathe operates for heavy machining. Flaws caused by flashes on the workpiece are prevented from occurring on the inner surface of the guide bush (11).

Abstract: 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.

Abstract: A guide bush (11), coming in sliding contact with a workpiece, for use in an automatic lathe is placed in a vacuum vessel (61), and after inserting an auxiliary electrode (71), which is grounded or to which a positive DC voltage is applied, in the center bore (11j) of the guide bush (11), forming the inner surface (11b) thereof, the vacuum vessel (61) is evacuated such that an initially reached pressure therein is not higher than a predetermined degree of vacuum. Then, after a DC voltage is applied to an anode (79) and an AC voltage is applied to a filament (81) while applying a DC voltage to the guide bush (11), carbon-containing gas is fed into the vacuum vessel (61), producing a plasma therein and the pressure inside the vacuum vessel (61) is controlled to attain a film-forming pressure higher than the initially reached pressure while forming a hard carbon film over the inner surface of the guide bush (11) by means of a plasma CVD process.

Abstract: The present invention provides a method of removing a hard carbon film (15) from the inner surface of a guide bush (11) through etching. The method comprises the steps of inserting an auxiliary electrode (71) in the center bore (11j) of the guide bush (11) wherein the hard carbon film (15) is formed over the inner surface thereof, in sliding contact with a workpiece, disposing the guide bush (11) with the auxiliary electrode inserted in the center bore thereof in a vacuum vessel (61) provided with an anode (79) and a filament (81) therein, grounding the auxiliary electrode (71) or applying a positive DC voltage thereto, and producing a plasma in the vacuum vessel (61) by feeding an oxygen-containing gas therein and applying a DC voltage to the anode (79) and an AC voltage to the filament (81) respectively, while applying a DC voltage to the guide bush (11) after evacuating the vacuum vessel (61).

Abstract: 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.

Abstract: 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.

Abstract: A hard carbon film is formed in a vacuum vessel directly or through an intermediate layer for enhancing adhesion over an inner surface of a guide bush with a uniform thickness and excellent adhesion 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 method comprises disposing the guide bush in a vacuum vessel, inserting an auxiliary electrode into the center bore forming the inner surface of the guide bush to be at a ground potential, introducing a gas containing carbon into the vacuum vessel through the gas inlet port after evacuating the vacuum vessel, and applying a DC voltage to the guide bush through a reactor, thereby producing a plasma in the vacuum vessel so that a hard carbon film of hydrogenated amorphous carbon is formed over the inner surface of the guide bush by a plasma CVD method.

Abstract: An auxiliary electrode which is to be connected to a ground potential or applied with a positive DC voltage is disposed in a center bore which forms an inner surface of a guide bush, and a ringlike dummy member made of a conductive material having an internal diameter equal to or larger than the diameter of the center bore of the guide bush with its both ends having a different diameter is placed on an end face of the guide bush opening the inner surface thereof so that one end having the smaller diameter contacts the end face of the guide bush with its center in alignment with the central axis of the center bore. A DLC film is formed over an inner surface of a guide bush which is in sliding contact with a workpiece held in the guide bush by disposing the guide bush in a vacuum vessel after evacuating the vessel and introducing a gas containing carbon, producing a plasma in a vacuum vessel by applying a DC voltage or a radio frequency power to the guide bush by the plasma CVD process.