Abstract: A sealing member according to the present invention is a sealing member against a synthetic oil containing an ester-type additive, and includes 95.0% by mass or more and 99.5% by mass or less of a para-phenylene diisocyanate-based polyurethane and 0.5% by mass or more and 5% by mass or less of a same compound as the ester-based additive. The sealing member according to the present invention has a smaller friction coefficient and more excellent deformability than conventional sealing members and that can inhibit swelling caused by a synthetic oil.

Abstract: A vibration damping device of an inverted structure includes a cylinder, a rod capable of protruding and retracting in the cylinder, an outer cylinder coupled to the rod and inserted over the outer periphery of the cylinder, and a bush slidably inserted between the outer cylinder and the cylinder. A gap between the outer cylinder and the cylinder is filled with lubricating oil. The bush contains polytetrafluoroethylene and perfluoro alkoxy alkane. The lubricating oil contains an organic molybdenum additive.

Abstract: This vibration damping device (10) includes a magnetorheological fluid composition in a cylinder (12). The magnetorheological fluid composition includes magnetic particles; a dispersant having the magnetic particles dispersed therein; and a friction modifier. The friction modifier is an ester-based additive having a hydrocarbon chain having 14 to 22 carbon atoms, preferably an alkyl chain or an alkenyl chain. The content of the friction modifier is 0.1 to 5 mass %.

Abstract: A damper device provided with a single cylinder type erecting structure having a free piston includes: a partition wall fixed to the cylinder between a piston and the free piston and partitioning inside of the cylinder into spaces in an axial direction of the cylinder; a partition wall orifice composed of an orifice piercing through the partition wall; a piston orifice composed of an orifice piercing through the piston; a partition wall-side flow variable structure configured to regulate a flow rate of a viscous fluid passing through the partition wall orifice; a piston-side flow variable structure configured to regulate a flow rate of the viscous fluid passing through the piston orifice; and a control unit configured to control the partition wall-side flow variable structure and the piston-side flow variable structure.

Abstract: A sealing member according to the present invention is a sealing member against a synthetic oil containing an ester-type additive, and includes 95.0% by mass or more and 99.5% by mass or less of a para-phenylen diisocyariate-based polyurethane and 0.5% by mass or more and 5% by mass or less of a same compound as the ester-based additive. The sealing member according to the present invention has a smaller friction coefficient and more excellent deformability than conventional sealing members and that can inhibit swelling caused by a synthetic oil.

Abstract: This vibration damping device (10) includes a magnetorheological fluid composition in a cylinder (12). The magnetorheological fluid composition includes magnetic particles; a dispersant having the magnetic particles dispersed therein; and a friction modifier. The friction modifier is an amine-based additive having a hydrocarbon chain having 14 to 22 carbon atoms, preferably an alkyl chain or an alkenyl chain. The content of the friction modifier is 0.1 to 5 mass %.

Abstract: An object of the present invention is to provide a vibration damping device including a bearing member capable of achieving simplification of configuration in the vibration damping device, reducing frictional force during operation, and having an excellent wear resistance. A vibration damping device of the present invention includes a bearing structure, in which a metal bush (bearing member) has a resin layer on a side defined as a friction sliding surface of a base member, the resin layer includes polytetrafluoroethylene and a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, and the metal bush is lubricated by a magneto-rheological fluid composition.

Abstract: A vibration damping device of an inverted structure includes a cylinder, a rod capable of protruding and retracting in the cylinder, an outer cylinder coupled to the rod and inserted over the outer periphery of the cylinder, and a bush slidably inserted between the outer cylinder and the cylinder. A gap between the outer cylinder and the cylinder is filled with lubricating oil. The bush contains polytetrafluoroethylene and perfluoro alkoxy alkane. The lubricating oil contains an organic molybdenum additive.

Abstract: A damper device provided with a single cylinder type erecting structure having a free piston includes: a partition wall fixed to the cylinder between a piston and the free piston and partitioning inside of the cylinder into spaces in an axial direction of the cylinder; a partition wall orifice composed of an orifice piercing through the partition wall; a piston orifice composed of an orifice piercing through the piston; a partition wall-side flow variable structure configured to regulate a flow rate of a viscous fluid passing through the partition wall orifice; a piston-side flow variable structure configured to regulate a flow rate of the viscous fluid passing through the piston orifice; and a control unit configured to control the partition wall-side flow variable structure and the piston-side flow variable structure.

Abstract: This vibration damping device (10) includes a magnetorheological fluid composition in a cylinder (12). The magnetorheological fluid composition includes magnetic particles; a dispersant having the magnetic particles dispersed therein; and a friction modifier. The friction modifier is an ester-based additive having a hydrocarbon chain having 14 to 22 carbon atoms, preferably an alkyl chain or an alkenyl chain. The content of the friction modifier is 0.1 to 5 mass %.

Abstract: An object of the present invention is to provide a vibration damping device including a bearing member capable of achieving simplification of configuration in the vibration damping device, reducing frictional force during operation, and having an excellent wear resistance. A vibration damping device of the present invention includes a bearing structure, in which a metal bush (bearing member) has a resin layer on a side defined as a friction sliding surface of a base member, the resin layer includes polytetrafluoroethylene (PTFE) and a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, and the metal bush is lubricated by a magneto-rheological fluid composition.

Abstract: This vibration damping device (10) includes a magnetorheological fluid composition in a cylinder (12). The magnetorheological fluid composition includes magnetic particles; a dispersant having the magnetic particles dispersed therein; and a friction modifier. The friction modifier is an amine-based additive having a hydrocarbon chain having 14 to 22 carbon atoms, preferably an alkyl chain or an alkenyl chain. The content of the friction modifier is 0.1 to 5 mass %.

Abstract: Provided is a technique whereby a DLC film having a desired surface roughness and a desired film hardness can be easily formed within a short period of time while preventing cost increase so that a large quantity of boll joints, which are less expensive and yet have stable sliding characteristics, can be supplied. A method for manufacturing a ball joint provided with a ball stud that has a spherical surface section and a holder section that pivotally holds the spherical surface section, said method comprising: an intermediate underlayer-forming step for forming an intermediate underlayer, that has a fine irregular surface structure, on the surface of the spherical surface section using a sputtering method; and an amorphous hard carbon film-forming step for forming an amorphous hard carbon film, that has a root mean square roughness on the surface of 6.5-35 nm, on the intermediate underlayer using a PIG plasma film formation method.

Abstract: Provided is a technique whereby a DLC film having a desired surface roughness and a desired film hardness can be easily formed within a short period of time while preventing cost increase so that a large quantity of boll joints, which are less expensive and yet have stable sliding characteristics, can be supplied. A method for manufacturing a ball joint provided with a ball stud that has a spherical surface section and a holder section that pivotally holds the spherical surface section, said method comprising: an intermediate underlayer-forming step for forming an intermediate underlayer, that has a fine irregular surface structure, on the surface of the spherical surface section using a sputtering method; and an amorphous hard carbon film-forming step for forming an amorphous hard carbon film, that has a root mean square roughness on the surface of 6.5-35 nm, on the intermediate underlayer using a PIG plasma film formation method.

Abstract: A sliding structural member is provided which achieves a good low frictional property. A DLC film 2 containing hydrogen is provided on one member 11 between members sliding against each other, and the one member and a counterpart member 12 are combined in such a way that the DLC film 2 provided on the one member 11 slides against the counterpart member via a lubricant 3 to which organic molybdenum compound and compound containing zinc and sulfur are added as an additive. A root mean square roughness of a surface of the DLC film 2 is set in a range from 5 nm or more to 25 nm or less, and hydrogen content of the DLC film 2 is set in a range from 4.5 at % (atomic %) or more to 30 at % or less.

Abstract: Provided is a ball joint having excellent wear resistance, corrosion resistance, and stability of sliding characteristics. A ball joint (1) according to the present invention includes: a ball stud (10) with a spherical surface section (11); and a resin seat (20) which holds and allows free rotation of the spherical surface section (11), wherein an amorphous hard carbon film with a hardness of 6 to 39 GPa is formed on the surface of the spherical surface section (11). In addition, in the ball joint (1) according to the present invention, the amorphous hard carbon film (DLC film) (12) preferably has a root mean square roughness of 60 nm or less. The resin seat (20) is preferably made of polyacetal, nylon, polyamide, polytetrafluoroethylene, polyether ether ketone, an elastomer, or a fiber-reinforced composite thereof.

Abstract: A sliding structural member is provided which achieves a good low frictional property. A DLC film 2 containing hydrogen is provided on one member 11 between members sliding against each other, and the one member and a counterpart member 12 are combined in such a way that the DLC film 2 provided on the one member 11 slides against the counterpart member via a lubricant 3 to which organic molybdenum compound and compound containing zinc and sulfur are added as an additive. A root mean square roughness of a surface of the DLC film 2 is set in a range from 5 nm or more to 25 nm or less, and hydrogen content of the DLC film 2 is set in a range from 4.5 at % (atomic %) or more to 30 at % or less.

Abstract: A carbon fiber composite material (10) is provided which includes carbon fibers (11), a matrix (12) binding the carbon fibers (11) together, and pores (13), and a volume fraction of the carbon fibers (11) exclusive of the pores (13) is not less than 45% and up to 80%. The carbon fiber composite material (10) may preferably have a porous structure of which a porosity is not more than 20% and up to 70%. This carbon fiber composite material (10) has a high static friction coefficient (?S), and low ? ratio, and thus is suitable for a wet friction member (e.g., carbon disc 5) which is excellent in both of static friction performance and dynamic friction performance.

Abstract: A friction member for a frictional engagement device is provided in which weight is reduced, impact resistance is enhanced and sliding resistance is improved; and also provided is a method for producing the same. As a friction member (10) for a frictional engagement device, a friction member made of a carbon fiber/carbonaceous composite material is provided which is obtained by implementing a heat treatment on a precursor, the precursor comprising a matrix composed of a carbon binder and an additive and carbon fiber dispersed in the matrix, wherein a porosity of the friction member is 20-60%.

Abstract: A carbon fiber composite material (10) is provided which includes carbon fibers (11), a matrix (12) binding the carbon fibers (11) together, and pores (13), and a volume fraction of the carbon fibers (11) exclusive of the pores (13) is not less than 45% and up to 80%. The carbon fiber composite material (10) may preferably have a porous structure of which a porosity is not more than 20% and up to 70%. This carbon fiber composite material (10) has a high static friction coefficient (?S), and low ? ratio, and thus is suitable for a wet friction member (e.g., carbon disc 5) which is excellent in both of static friction performance and dynamic friction performance.