Abstract: Provided is a valve seat insert for an internal combustion engine, which has both an excellent heat dissipation property and excellent wear resistance. The valve seat insert for an internal combustion engine is used while being press-fitted into an aluminum alloy cylinder head, is made of an iron-based sintered alloy, is formed by integrating two layers of a functional member side layer and a supporting member side layer, and has a plating film on at least an outer peripheral side. The plating film is preferably a copper plating film. The plating film is a plating film having a thickness of 1 to 100 ?m and a hardness of 50 to 300 HV, and the hardness of the plating film is adjusted so as to satisfy a range of 1.05 to 4.5 times hardness of the cylinder head in Vickers hardness HV. Pores contained in the valve seat insert are preferably sealed with a curable resin before plating treatment.

Abstract: Provided is a valve seat insert for an internal combustion engine, which has both an excellent heat dissipation property and excellent wear resistance. The valve seat insert for an internal combustion engine is used while being press-fitted into an aluminum alloy cylinder head, is made of an iron-based sintered alloy, is formed by integrating two layers of a functional member side layer and a supporting member side layer, and has a plating film on at least an outer peripheral side. The plating film is preferably a copper plating film. The plating film is a plating film having a thickness of 1 to 100 ?m and a hardness of 50 to 300 HV, and the hardness of the plating film is adjusted so as to satisfy a range of 1.05 to 4.5 times hardness of the cylinder head in Vickers hardness HV. Pores contained in the valve seat insert are preferably sealed with a curable resin before plating treatment.

Abstract: Disclosed is a copper-infiltrated valve seat insert of an iron-base sintered alloy having a two-layer structure formed by integrating a functional member side layer and a supporting member side layer across a boundary, and the thermal conductivity rate at 300° C. is 25 W/m·K or more in the functional member side layer and 60 W/m·K or more in the supporting member side layer.

Abstract: A valve seat insert made of an iron-base sintered alloy is configured to have a structure in which the base matrix phase is a fine carbide precipitation phase in which a fine carbide being 10 ?m or less in size is precipitated and which has a hardness of 550 HV or more in Vickers hardness; and in the base matrix phase, hard-particles having a hardness of 650-1200 HV in Vickers hardness are dispersed in an area percentage of 20-40%, a diffusional phase is formed in an area percentage of more than 0% and not more than 5%, and solid-lubricant particles are dispersed in an area percentage of 0-5%. Even if a valve having a high face hardness of 400 HV or more, or 600 HV or more is used, a facing valve seat insert wears only slightly, improving valve train durability.

Abstract: A highly wear-resistant valve seat insert for an internal combustion engine, having a material composition in which hard-particles are uniformly and finely dispersed in the matrix phase, and which is excellent in wear-resistance and radial crushing strength, based on a blended fine powder and a matrix forming powder with a particle size approximately equal to that of the hard-particles so as to prevent the hard-particles from aggregating and thus coarsely dispersing as a hard-particle phase.

Abstract: In an assembly of a hollow poppet valve and a valve seat insert, the hollow poppet valve's head is integrally formed with a stem end, a hollow part is formed from the head to a stem, and coolant is filled into the hollow part along with an inert gas. The valve seat insert is formed of iron base sintered alloy and obtained by integrating two layers of a supporting material side layer and a valve contact face side layer. The hollow poppet valve is formed of a material having thermal conductivity of 5-45 (W/m·K) at 20-1000° C. The valve seat insert includes the supporting material side layer having thermal conductivity of 23-50 (W/m·K) at 20-300° C. and a valve contact face side layer having thermal conductivity of 10-22 (W/m·K) at 20-300° C. This enables a valve temperature decrease throughout an engine's entire RPM range compared with the prior art.

Abstract: Provided is a valve seat insert made of an iron-base sintered alloy, in which a base matrix part that includes a base matrix phase and hard particles, has a base matrix part composition containing, in % by mass, 0.5%-2.0% of carbon and 10%-70% in total of one kind or two or more kinds selected from nickel, cobalt, chromium, molybdenum, vanadium, tungsten, manganese, silicon and sulfur, with the balance being iron and unavoidable impurities, and Co-base hard particles having a composition containing, 1.0% or less of C, 25%-50% of Mo, 5%-15% of Cr, Si as an impurity in a content adjusted to be 0.3% or less, with the balance being Co, and having a Vickers hardness of 500 to 1,500 HV, are dispersed as hard particles in the base matrix phase in an amount of 10%-60% by mass with respect to the total amount of the valve seat insert.

Abstract: A valve seat insert made of an iron-base sintered alloy is configured to have a structure in which the base matrix phase is a fine carbide precipitation phase in which a fine carbide being 10 ?m or less in size is precipitated and which has a hardness of 550 HV or more in Vickers hardness; and in the base matrix phase, hard-particles having a hardness of 650-1200 HV in Vickers hardness are dispersed in an area percentage of 20-40%, a diffusional phase is formed in an area percentage of more than 0% and not more than 5%, and solid-lubricant particles are dispersed in an area percentage of 0-5%. Even if a valve having a high face hardness of 400 HV or more, or 600 HV or more is used, a facing valve seat insert wears only slightly, improving valve train durability.

Abstract: An iron-base sintered alloy material includes a matrix phase, Co base inter-metallic compound particles having hardness of 600 to 1200 HV, carbide-type particles having hardness of 400 to 700 HV, and optionally solid-lubricant particles, the particles being dispersed in the matrix phase. A matrix part including the matrix phase and the two kinds of hard-particles contains 0.3 to 1.5% by mass of C, and 10 to 50% by mass of one or more kinds selected from Si, Mo, Cr, Ni, Co, Mn, S, N, V, Ca, F, Mg, and O, the balance being Fe and unavoidable impurities. By dispersing, in the matrix phase, the Co base inter-metallic compound particles having high hardness, and the carbide-type particles having low hardness and low aggressiveness to mated material and increasing mechanical strength, wear-resistance can be improved with low aggressiveness to mated material and high radial crushing strength (350 MPa or more).

Abstract: Provided is a valve seat insert made of an iron-base sintered alloy, in which a base matrix part that includes a base matrix phase and hard particles, has a base matrix part composition containing, in % by mass, 0.5%-2.0% of carbon and 10%-70% in total of one kind or two or more kinds selected from nickel, cobalt, chromium, molybdenum, vanadium, tungsten, manganese, silicon and sulfur, with the balance being iron and unavoidable impurities, and Co-base hard particles having a composition containing, 1.0% or less of C, 25%-50% of Mo, 5%-15% of Cr, Si as an impurity in a content adjusted to be 0.3% or less, with the balance being Co, and having a Vickers hardness of 500 to 1,500 HV, are dispersed as hard particles in the base matrix phase in an amount of 10%-60% by mass with respect to the total amount of the valve seat insert.

Abstract: In an assembly of a hollow poppet valve and a valve seat insert, the hollow poppet valve's head is integrally formed with a stem end, a hollow part is formed from the head to a stem, and coolant is filled into the hollow part along with an inert gas. The valve seat insert is formed of iron base sintered alloy and obtained by integrating two layers of a supporting material side layer and a valve contact face side layer. The hollow poppet valve is formed of a material having thermal conductivity of 5-45 (W/m·K) at 20-1000° C. The valve seat insert includes the supporting material side layer having thermal conductivity of 23-50 (W/m·K) at 20-300° C. and a valve contact face side layer having thermal conductivity of 10-22 (W/m·K) at 20-300° C. This enables a valve temperature decrease throughout an engine's entire RPM range compared with the prior art.

Abstract: A highly wear-resistant valve seat insert is provided. When an iron-based powder, a hard-particle powder, and a graphite powder are mixed to obtain a mixed powder, for formation of a layer on a valve-contacting face side, the hard-particle powder having an average particle size 15-50 ?m, and the iron-based powder having an average particle size 15-50 ?m are blended so a matrix part composition after sintering is a composition containing C: 0.3 to 2.0% by mass, one or more kinds selected from Co, Si, Ni, Mo, Cr, Mn, S, W, and V at 70% by mass or less in total, the balance being Fe and unavoidable impurities and a matrix part structure after sintering is a structure which contains hard-particles at from 10 to 65% by mass with respect to a total amount of a layer on a valve-contacting face side and disperses the hard-particles at 1000 particles/mm2 or more.

Abstract: An iron-base sintered alloy material includes a matrix phase, Co base inter-metallic compound particles having hardness of 600 to 1200 HV, carbide-type particles having hardness of 400 to 700 HV, and optionally solid-lubricant particles, the particles being dispersed in the matrix phase. A matrix part including the matrix phase and the two kinds of hard-particles contains 0.3 to 1.5% by mass of C, and 10 to 50% by mass of one or more kinds selected from Si, Mo, Cr, Ni, Co, Mn, S, N, V, Ca, F, Mg, and O, the balance being Fe and unavoidable impurities. By dispersing, in the matrix phase, the Co base inter-metallic compound particles having high hardness, and the carbide-type particles having low hardness and low aggressiveness to mated material and increasing mechanical strength, wear-resistance can be improved with low aggressiveness to mated material and high radial crushing strength (350 MPa or more).

Abstract: A liquid discharge apparatus includes: movable head having a nozzle line with nozzles arranged in a predetermined direction; and a control unit that performs a first liquid discharge process and a second liquid discharge process, which sequentially form dots on a medium by intermittently discharging liquid from the nozzles while moving the head and maintaining the inclusion of a normal component perpendicular to the predetermined direction in the moving direction of the head and which form dots on the medium such that a dot formation position in the perpendicular direction of the dots formed in the second liquid discharge process is positioned between dot formation positions in the perpendicular direction of the dots formed continuously in the first liquid discharge process.

Abstract: It is an object of the present invention to provide a valve seat product in which the amount of hard particles added to improve the wear resistance of a valve seat of an internal combustion engine is increased, and is excellent in the mechanical strength and machinability.

Abstract: A liquid discharge apparatus includes: movable head having a nozzle line with nozzles arranged in a predetermined direction; and a control unit that performs a first liquid discharge process and a second liquid discharge process, which sequentially form dots on a medium by intermittently discharging liquid from the nozzles while moving the head and maintaining the inclusion of a normal component perpendicular to the predetermined direction in the moving direction of the head and which form dots on the medium such that a dot formation position in the perpendicular direction of the dots formed in the second liquid discharge process is positioned between dot formation positions in the perpendicular direction of the dots formed continuously in the first liquid discharge process.

Abstract: It is an object of the present invention to provide a valve seat product in which the amount of hard particles added to improve the wear resistance of a valve seat of an internal combustion engine is increased, and is excellent in the mechanical strength and machinability.

Abstract: An image processing apparatus includes a first display image data generation unit which acquires image data and generates first display image data including information about a plurality of pixels, a histogram generation unit which generates a histogram showing luminance distribution of the pixels contained in the first display image data, a second display image data generation unit which generates second display image data by taking a domain corresponding to a predetermined percent with high luminance among the entire luminance distribution area as a cutoff domain in the histogram generated by the histogram generation unit, setting up the luminance of the pixels in the cutoff domain to 100%, and changing the luminance of the pixels whose luminance is in a range from 0% to a cutoff luminance value which is a minimum luminance of the pixels in the cutoff domain to be 0 to 100% while maintaining the luminance distribution, an image display unit which has a backlight and displays an image on the basis of the sec

Abstract: An internal combustion engine includes, in combination, an intake side valve system and an exhaust side valve system. Each of the valve systems comprises a valve seat and a valve member to be assembled with the valve seat, in which the valve seat has a base member including a matrix of iron-base sintered alloy and a dispersed Si—Cr—Mo—Co group intermetallic compound powder, the intermetailic compound powder having a hardness of Hv600 to Hv1000 and an average particle diameter of 20 to 70 &mgr;m, the matrix being contained at 10 to 50 mass % with reference to total mass of the base member, and the valve member has a base member including a matrix of martensitic steel and a nitriding diffusion layer formed to a valve face of the base member, the nitriding diffusion layer having a hardness of more than Hv500 and a thickness of more than 20 &mgr;m.

Abstract: A process for manufacturing a valve seat which is made of a sintered Fe alloy and comprises a main layer of a valve seat and a contacting layer, comprises the steps of preparing either a powdery Cu or a powdery material containing Cu in a powdery Fe alloy, forming a green compact body with two green compact body layers, one of which is the main layer and the other of which is the contacting layer, and which are made of the prepared powdery Fe alloy containing Cu, sintering the green compact body. According to the present invention, the infiltration of Cu from the main layer to the contacting layer of the valve seat is not generated as the conventional sintering process for manufacturing the valve seat comprising the two layers without the independent infiltration treatment of Cu, and, therefore, the valve seat obtained of the present invention has an high abrasion resistance without decreasing of a strength of the main layer.