Abstract: A piston for an internal combustion engine, the piston having a skirt part, comprises: a resinous coating layer formed on a surface of the skirt part; and a plurality of concaves regularly arranged in the resinous coating layer. The concaves are non-coated regions in which said resinous coating layer is not formed.

Abstract: A compound sheet gasket which exhibits superior sealing durability to fretting is provided. The compound sheet gasket is mounted between a housing and a cover provided at an opening of the housing, and the friction coefficient of any one surface of a front surface adhered to the housing by the flexibility thereof and a rear surface adhered to the cover by the flexibility thereof, is set to be 1.15 times or more that of the other.

Abstract: The gasket material that is manufactured from a joint seat which includes three layers, that is, a front surface layer (1a), a back surface layer (1b) and the middle layer (1c), and these layers have different composition of reinforced fiber and filler respectively, and this joint seat is made from an ingredient made by mixing and kneading rubber, reinforced fiber and filler, then pressurized laminating and vulcanizing the ingredient, this joint seat is characterized in that the reinforced fiber is as a sort of fibril which is composed from one or both of organic fiber and non-asbestos type inorganic fiber, and at least a part of the filler is spicular inorganic fiber and its composition is 10 wt %-45 wt %. According to this joint seat (1), a crack breakage of the gasket that the ingredient material is the joint seat (1) due to fretting is prevented.

Abstract: A gasket material including a joint sheet (1) having been formed from raw materials obtained by kneading a rubber, a reinforcing fiber and a filler by a method involving pressuring, laminating and vulcanizing with a calendar roll, characterized in that at least a surface layer (1a) being an outermost layer on the cold roll side is so formed as to have a flexible and smooth face. The gasket material including the joint sheet (1) can provide a gasket which is markedly improved in the sealing property in a low face pressure region, as compared to a conventional similar gasket.

Abstract: Disclosed is a metal gasket which is capable of securing a sealing properties by strongly pressing a portion of a bead thereof, which faces a portion where a pressuring surface of one joining surface of one of an intake manifold and an EGR plate does not exist, to the other joining surface thereof. A metal gasket which is clamped between the two joining surfaces and has at least one hole for fluid, includes a bead for sealing the two joining surfaces, the bead surrounding the at least one hole for fluid, each of which allows openings for fluid to be communicated with each other, the openings being provided in the respective joining surfaces. The metal gasket further includes a convex portion, the tip of which abuts one of the joining surfaces, is provided in the vicinity of a portion of the beads abutting the other joining surface.

Abstract: A metal gasket material plate has improved adhesion of a rubber layer to a metal plate by use of an adhesive layer, so as to prevent the rubber layer from happening delamination of the metal plate and to provide a chromium-free material plate in consideration of adverse effects on the environment and a human body. In a laminated metal gasket material plate provided with a rubber layer on a metal plate by use of an adhesive layer, the metal gasket material plate includes silane-based chemical conversion coating being formed between a surface of the metal plate and the adhesive layer by applying a silane coupling agent containing any of an epoxy group, a mercapto group, and an amino group as a functional group. Here, the adhesive layer is made of a phenol resin-based adhesive, and the rubber layer is made of an NBR-based rubber mixture.

Abstract: An expansion graphite sheet of high thermal resistance includes an expansion graphite as a main component, and inorganic thermal resistance particles made of at least one selected from the group consisting of aluminum boride (AlB2 and/or AlB12), silicon boride (SiB6), zinc boric acid (2ZnO.3B2O3.3.5H2O) and phosphorous boride (PB). An exhaust gasket made of the expansion graphite sheet, in addition to the expansion graphite sheet, can exhibit high thermal (oxidization) resistance under a high temperature of 600-700° C.

Abstract: Provided is a gasket capable of maintaining a high sealing property under a high temperature, in which a gasket basic substance and coverture are not sublimated or decomposed when the gasket is used under a high temperature above 500° C. The gasket for a high-temperature joint includes a gasket basic substance formed by filling a heat-resistant filler mainly composed of diatomaceous earth into gaps of a meshed metallic reinforcing member, and coverture made of a heat-resistant antifriction material mainly composed of a mixture of boron nitride and polytetrafluoroethylene resin for covering a surface of the gasket basic substance.

Abstract: Optical amplifier according to the present invention is provided with an EDF, a light source device having a semiconductor laser element that generates an excitation beam and a housing that accommodates this, and an optical multiplexer having an input optically coupled with light source device, an input that receives the signal beam, and an output that provides an excitation beam and signal beam to EDF. Semiconductor laser element has an active layer, provided between cladding layers and including compound semiconductors of mutually different conductivity types, that includes a compound semiconductor and is constructed such that the oscillation wavelength at 20° C. of this semiconductor laser element is less than 1470 nm but not less 1440 nm. If this is done, the change of gain in EDF with respect to oscillation wavelength can be made satisfactorily small and the NF can be made satisfactorily small.

Abstract: The composite material for a metal gasket includes a metal plate; a rubber layer fixed on the surface of the metal plate; and a solid lubricant layer fixed on the rubber layer. The solid lubricant layer contains polytetrafluoroethylene and a resin as main components, and has a friction coefficient equal to 0.15 or lower. Thus, the seal durability of the metal gasket is improved by effectively preventing fretting wear.

Abstract: Optical amplifier according to the present invention is provided with an EDF, a light source device having a semiconductor laser element that generates an excitation beam and a housing that accommodates this, and an optical multiplexer having an input optically coupled with light source device, an input that receives the signal beam, and an output that provides an excitation beam and signal beam to EDF. Semiconductor laser element has an active layer, provided between cladding layers and including compound semiconductors of mutually different conductivity types, that includes a compound semiconductor and is constructed such that the oscillation wavelength at 20° C. of this semiconductor laser element is less than 1470 nm but not less 1440 nm. If this is done, the change of gain in EDF with respect to oscillation wavelength can be made satisfactorily small and the NF can be made satisfactorily small.

Abstract: A variable geometry turbocharger in which a bill-like projection portion is arranged in a part of an outer periphery of a flow passage spacer, and the projection portion is protruded to a turbine rotor side at a predetermined angle or the projection portion is movably provided. Alternatively, a rod-like member is arranged in a part of an outer periphery of a flow passage spacer and the rod-like member is arranged so as to be adjacent to the turbine rotor side at a predetermined angle. Alternatively, a guide vane in which a leading edge side of a rotational shaft is eliminated is arranged in a part of an outer periphery of a flow passage spacer and the rotational shaft is arranged so as to be adjacent to the turbine rotor side at a predetermined angle.

Abstract: The present invention relates to a WDM transmission system and the like suitable for optical communications between local stations having a relatively short repeater interval. In particular, the WDM transmission repeater employed in the WDM transmission system demultiplexes a plurality of signal lights propagating through a transmission line into first and second groups, takes out the second group, comprises a multiplexer for sending into the transmission line a new WDM signal group in which the first group thus demultiplexed and a third group of signal lights different from those of the first group are multiplexed, and has a special structure for reducing the influence of the not-demultiplexed crosstalk components within the second group upon the optical communications.

Abstract: Disclosed is a metal gasket which is capable of securing a sealing properties by strongly pressing a portion of a bead thereof, which faces a portion where a pressuring surface of one joining surface of one of an intake manifold and an EGR plate does not exist, to the other joining surface thereof. A metal gasket which is clamped between the two joining surfaces and has at least one hole for fluid, includes a bead for sealing the two joining surfaces, the bead surrounding the at least one hole for fluid, each of which allows openings for fluid to be communicated with each other, the openings being provided in the respective joining surfaces. The metal gasket further includes a convex portion, the tip of which abuts one of the joining surfaces, is provided in the vicinity of a portion of the beads abutting the other joining surface.

Abstract: Provided is a gasket capable of maintaining a high sealing property under a high temperature, in which a gasket basic substance and coverture are not sublimated or decomposed when the gasket is used under a high temperature above 500° C. The gasket for a high-temperature joint of this invention includes a gasket basic substance formed by filling a heat-resistant filler mainly composed of diatomaceous earth into gaps of a meshed metallic reinforcing member, and coverture made of a heat-resistant antifriction material mainly composed of a mixture of boron nitride and polytetrafluoroethylene resin for covering a surface of the gasket basic substance.

Abstract: A composite material for a metal gasket is disclosed, including: a metal plate; a rubber layer fixed on the surface of the metal plate; and a solid lubricant layer fixed on the rubber layer. The solid lubricant layer contains polytetrafluoroethylene and a resin as main components, and has a friction coefficient equal to 0.15 or lower.

Abstract: A compound sheet gasket which exhibits superior sealing durability to fretting is provided. The compound sheet gasket is mounted between a housing and a cover provided at an opening of the housing, and the friction coefficient of any one surface of a front surface adhered to the housing by the flexibility thereof and a rear surface adhered to the cover by the flexibility thereof, is set to be 1.15 times or more that of the other.

Abstract: A cutting insert (2) having a tip bit. (5) and a tabular tip body (4) supporting the tip. The cutting insert (2) is used by being mounted to the body (1) of a cutting tool. Wherein, the tip body (4) has a plurality of elastic deformation sections (8) separated by a slit (6) which extends on a transverse line from a corner to an area near another corner. The elastic deformation sections are moved closer together and elastically deformed within a plane which includes the tip body 4 when being mounted to the tool body 1. And, the opposing faces of the elastic deformation sections (8) have engaging sections (10) for engaging the tip bit (5).

Abstract: A high performance drill bit is presented for precision drilling of holes in hard-to-drill materials, such as a carbon fiber reinforced plastic material. The drill is a gun drill type having a pair of flat flutes and a pair of air holes for delivering coolant and/or lubricant. The main feature of the drill is the provision of two pairs of cutting edges formed on the intersecting ridges formed at the leading sides of the flank surfaces with the flute surfaces. At the tip of the drill bit, a pair of primary cutting edges, having a point angle .alpha., is disposed. It is followed by another pair of secondary cutting edges, having a point angle .beta., where .alpha.>.beta.. Physically, this means that the secondary cutting edges are inclined more toward the drill axis than the primary cutting edges. The secondary cutting edge is followed further by another flank surfaces which are even more inclined toward the drill axis.

Abstract: A ball end mill is disclosed which includes a tool body having an axis of rotation therethrough and having a forward end portion, and a cutting edge provided on the forward end portion of the tool body and having an arcuate shape as viewed in a direction opposite to the direction of rotation of the tool body. The cutting edge is comprised of a radially inner portion disposed adjacent to the axis of rotation of the tool body and extending radially inwardly of the tool body in a direction opposite to the direction of rotation of the tool body, and a radially outer portion extending from the inner portion radially outwardly and axially rearwardly of the tool body. Each of the inner and outer portions of the cutting edge is formed of a two-layered composite sintered complex having a base layer of cemented carbide and an upper layer of sintered super hardened compact disposed on the base layer and containing cubic boron nitride, diamond or the like.