Nippon Piston Ring Co., Ltd.

Kao Corporation

Honda Motor Co., Ltd.

Nittan Valve Co., Ltd.

Kenichi Sato

Hiroshi Oshige

Teruo Takahashi

Yoshinobu Machida

Arata Kakiuchi

Yuichi Ishino

Minoru Tsukada

Kenji Ando

Satoshi Ikemi

Kiyoshi Suwa

Katsuaki Ogawa

Tomoki Okita

Masao Ishida

Takuaki Harada

Hiroyuki Oketani

Ayato Oikawa

Kazuyuki Maeda

Yasuhiro Umeki

Kouji Kunitake

Ryouichi Yoshino

Masahiro Takehana

Hiroshi Hirasawa

Yasuhiro Nakano

Takeshi Haniu

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 &#x3bc;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. Consequently, a valve seat insert for an internal combustion engine which does not go through complicated processes, is not accompanied by a significant decrease in wear resistance compared with the prior art, and has an excellent heat dissipation property is provided. If a roughened surface region is further formed at at least one portion on the outer peripheral surface of the valve seat insert in addition to the plating film, a falling out resistance property is improved. The same effect can be obtained even if the valve seat insert is a single layer of only the functional member side layer.

Iron-based sintered alloy valve seat for internal combustion engine

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.

Highly wear-resistant valve seat for use in internal combustion engine

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&#xb7;K) at 20-1000&#xb0; C. The valve seat insert includes the supporting material side layer having thermal conductivity of 23-50 (W/m&#xb7;K) at 20-300&#xb0; C. and a valve contact face side layer having thermal conductivity of 10-22 (W/m&#xb7;K) at 20-300&#xb0; C. This enables a valve temperature decrease throughout an engine's entire RPM range compared with the prior art.

Assembly of internal combustion engine valve and valve seat

Disclosed is a composite sheetcomposed of a substantially flat lower fibrous sheetand an upper fibrous sheetbonded to the lower fibrous sheet. The upper fibrous sheetis three-dimensionally textured with a number of projectionsand a number of depressioneach of which is located between every adjacent two of the projections. The projectionsand the depressionsalternate in both a first direction of the composite sheetand a second direction perpendicular to the first direction. Each projectionhas a pair of opposing first wallsparallel to the first direction and a pair of opposing second wallsparallel to the second direction. The basis weight of the first wallsis different from that of the second walls

Composite sheet

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. In order to achieve the object, an iron-based sintered alloy material for a valve seat is employed which is made to contain a first hard particle having an average primary particle diameter of 5 to 20 &#x3bc;m and a second hard particle having an average primary particle diameter of 20 to 150 &#x3bc;m in a texture, wherein a particle size distribution curve measured by laser diffraction scattering analysis has N peaks (N is an integer equal to or larger than 2) and when particle diameters corresponding to the peak top positions are denoted as Dto D, a peak top particle diameter difference between neighboring Dand D(|D&#x2212;D|: n is an integer equal to or larger than 2 and equal to or smaller than N) is in the range of 15 to 100 &#x3bc;m in at least one neighboring Dand D; and the total area ratio occupied by both of the first hard particle and the second hard particle constituting the mixed hard particle in the texture of the iron-based sintered alloy is 10 to 60% by area.

Iron-based sintered alloy for valve seat, and valve seat for internal combustion engine

A composite sheet comprising an upper layerand a lower layerboth made of a substantially inextensible sheet which are partially bonded to each other at a large number of joints. The upper layerforms a large number of outward hollow projectionsin the area other than the joints. The projectionsand the jointsare arranged such that the projections and the joints alternate in one direction to make lines and that the projections in each of the lines are out of alignment with the projections in the adjacent lines.

Apparatus for producing a composite sheet

Composite sheet and process and apparatus for producing the same

An iron-based sintered alloy material for a valve seat having improved wear resistance and reduced opposite aggressibility to a mating valve. The iron-based sintered alloy material contains 10% to 20% by area of first hard particles and 15% to 35% by area of second hard particles dispersed in a base matrix phase, the first and the second hard particles accounting for 25% to 55% by area in total. The first hard particles are composed of a cobalt-based intermetallic compound and have a size of 10 to 150 &#x3bc;m and a hardness of at least 500HV0.1 and less than 800HV0.1. The second hard particles are composed of a cobalt-based intermetallic compound and have a size of 10 to 150 &#x3bc;m and a hardness of at least 800HV0.1 and less than 1100HV0.1. Solid lubricant particles may also be dispersed in the base matrix phase.

Iron-based sintered alloy material for valve seat

A valve seat, press-fitted into a cylinder head of an internal combustion engine, containing an iron-based sintered alloy, includes a valve-seating section and a head-seating section. The valve-seating section and the head-seating section are monolithically formed by a sintering process and form a double layer structure. The valve-seating section includes a first iron-based sintered alloy member that has a porosity of 10 to 25 percent by volume and a sintered density of 6.1 to 7.1 g/cmand contains hard particles dispersed in a matrix. The head-seating section includes a second iron-based sintered alloy member that has a porosity of 10 to 20 percent by volume and a sintered density of 6.4 to 7.1 g/cm.

Sintered alloy valve seat and method for manufacturing the same

There is disclosed a method for manufacturing particle deposited body comprising supplying, under sucking condition, particles entrained by air on a continuous carrier sheet which is running at a prescribed direction to deposit the particles on the carrier sheet, thereby obtaining a particle deposited body comprising the particles and the carrier sheet, the carrier sheet having an air-permeability of 4.0 seconds/(300 ml&middot;32 pcs.) or less.

Method for manufacturing particle deposited body

A valve seat made of an iron base sintered alloy for internal combustion engines comprises of hard particles of hardness 700-1300 Hv dispersed by 3-20% by volume in a matrix phase comprising comprising of a 5-40% psarlite phase, a 20-60% fine carbide dispersed phase, and a 5-20% high alloy diffusd phase. The hard paricles are preferably selected from a group of Mo--Ni--Cr--Si--Co intermetallic compound particles, Cr--Mo--Co intermetallic compound particles, and Fe--Mo alloy particles. The iron base sinteed alloy is conpised of, by weight, C: 0.2-2.0%, Cr: 1.0-9.0%, Mo: 1.0-9.0%, Si: 0.1-1.0%, W: 1.0-50%, V: 0.2-3.0%, one or more Cu, Co and Ni of 0.5-10.0% in total, and the remainder substantial Fe.

Growing community of inventors

Tochigi, Japan

Kenichi Sato