Patents Assigned to Nippon Piston Ring Co., Ltd.
  • Publication number: 20090013866
    Abstract: A three-piece oil ring and a combination of the three-piece oil ring and a piston, those capable of realizing improved sealing property and reduction in lubrication oil consumption with avoiding generation of sticking even at low tension and thin width of the ring. The three-piece oil ring includes a spacer expander 10 and two side rails. The spacer expander has a radially inner end portion provided with seating tabs 13 protruding in an axial direction and having radially outer inclined surfaces for urging inner peripheral surfaces of the first and second side rails. The spacer expander has a radially outer end portion provided with side rail support portions 14 projecting in the axial direction for supporting axial end faces of the first and second side rails. A seating tab angle of the outer inclined surface relative to an axis is in a range of 10 to 20 degrees, and a ratio of 2X/Y is in a range of from 0.04 to 0.
    Type: Application
    Filed: January 30, 2007
    Publication date: January 15, 2009
    Applicant: NIPPON PISTON RING CO., LTD.
    Inventor: Tomotaka Kariya
  • Patent number: 7354045
    Abstract: It is a main object of the present invention to provide an oil ring which is capable of reducing sliding friction even in a high speed revolution region of a piston, and capable of reducing the consumption of oil.
    Type: Grant
    Filed: October 28, 2003
    Date of Patent: April 8, 2008
    Assignees: Toyota Jidosha Kabushiki Kaisha, Nippon Piston Ring Co., Ltd.
    Inventors: Tomoaki Abe, Keishi Nanno, Shiro Shibata, Hideshi Hitosugi
  • Publication number: 20080053396
    Abstract: The disclosed is a combination of a cylinder liner and a piston ring which contacts to a inner circumference surface of the cylinder liner at the pressure of 0.03 to 0.2 MPa, wherein the composition of the cylinder liner includes, silicon: 23.0 to 28.0% by weight, magnesium: 0.80 to 2.0% by weight, copper: 3.0 to 4.5% by weight, iron: 0.25% by weight or less, nickel: 0.01% by weight or less, and the rest: unavoidable impurities and aluminum, and wherein surface roughness profile of the inner circumference surface has Rz 0.5 to 1.0 ?m, Rk=0.2 to 0.4 ?m, Rpk=0.05 to 0.1 ?m, Rvk=0.08 to 0.2 ?m, meanwhile, wherein the composition of a piston ring includes carbon: 0.6 to 0.7% by weight, chrome: 13 to 14% by weight, molybdenum: 0.2 to 0.4% by weight, silicon: 0.25 to 0.50% by weight, manganese: 0.2 to 0.5% by weight, and the rest: unavoidable impurities and iron, and wherein carbides with the diameter of 5.
    Type: Application
    Filed: August 30, 2007
    Publication date: March 6, 2008
    Applicant: NIPPON PISTON RING CO., LTD.
    Inventors: Iwao HIRAISHI, Katsuaki Ogawa, Hiromi Ishikawa, Tsugane Hirase, Kazuhiro Sameshima
  • Publication number: 20070261658
    Abstract: A piston for an internal-combustion engine includes a through-hole communicating with the inner space of the piston formed in an oil-ring groove into which an oil ring is fitted and a through-hole connected with a second-ring groove, the through-hole having an opening spreading from the lower portion of the bottom of the second-ring groove in a top-to-bottom direction of the piston to the lower surface of the second-ring groove and linearly extending to the inner space of the piston; and a combination of the piston and piston rings of the three-ring type for an internal-combustion engine, the end gaps of compression rings among the piston rings being set in a predetermined range.
    Type: Application
    Filed: November 22, 2005
    Publication date: November 15, 2007
    Applicant: Nippon Piston Ring Co., Ltd.
    Inventors: Tomoaki Abe, Hideshi Hitosugi
  • Patent number: 7273508
    Abstract: 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 ?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 ?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.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: September 25, 2007
    Assignees: Nippon Piston Ring Co., Ltd., Honda Motor Co., Ltd.
    Inventors: Kenichi Sato, Arata Kakiuchi, Teruo Takahashi, Tomoki Okita, Masahiro Takehana
  • Patent number: 7166255
    Abstract: The temporary compacting of the powder for use in sintering is carried out, the temporary sintering is carried out, the main compacting is carried out, the main sintering is carried out, and the thickness of the radius direction of the base part of the cam before the heat-treatment is set to 3.0 mm or more.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: January 23, 2007
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventors: Shunsuke Takeguchi, Hiroyuki Takamura
  • Publication number: 20070006828
    Abstract: The present invention provides a cam lobe material that is excellent in sliding characteristics, such as wear resistance, scuffing resistance and pitting resistance, and can be advantageously used in engines to which high loads are applied, and a method of manufacturing the cam lobe material. The above-described task is fulfilled by providing a cam lobe material that is formed from an iron-based sintered alloy that contains 0.3 to 5.0 mass % Ni, 0.5 to 1.2 mass % C, 0.02 to 0.3 mass % of at least either of B and P, and incidental impurities as the balance, and has a hardness of a peripheral surface of not less than HRC 50 and a density of not less than 7.5 g/cm3. The iron-based sintered alloy can further contain not more than 2.5 mass % Mo.
    Type: Application
    Filed: July 28, 2004
    Publication date: January 11, 2007
    Applicant: Nippon Piston Ring Co., Ltd
    Inventors: Hiroyuki Takamura, Shunsuke Takeguchi
  • Patent number: 7153337
    Abstract: The object of the invention is to provide a porous metal structure body suitable for reinforcing a light metal alloy member such as an aluminum alloy member. A mixed powder containing a metallic powder is filled in a mold, and is molded into a shape having a single cavity or plural cavities in the inner portion while having a maximum thickness of 6 mm or less at the surface portion side. The molded powder body is sintered to form into the porous metal structure body having a porosity of 20 to 50% by volume at the portions except the cavities. It is preferable that the metallic powder sintered body having a porosity of exceeding 50% by volume is formed into the cavities by being monolithically integrated with the porous metal structure body. Consequently, a structure being lightweight, having a high mechanical strength and being excellent in handling performance while being excellent in impregnability can be obtained.
    Type: Grant
    Filed: August 27, 2003
    Date of Patent: December 26, 2006
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventor: Hiroshi Takiguchi
  • Patent number: 7089902
    Abstract: 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/cm3 and 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/cm3.
    Type: Grant
    Filed: January 7, 2004
    Date of Patent: August 15, 2006
    Assignees: Nippon Piston Ring Co., Ltd., Honda Motor Co., Ltd.
    Inventors: Kenichi Sato, Arata Kakiuchi, Teruo Takahashi, Masao Ishida, Hiroyuki Oketani
  • Patent number: 7059290
    Abstract: A cylinder liner for use in an internal combustion engine has an inner peripheral surface at which a surface treatment layer is formed upon water vapor treatment. The surface treatment layer has a surface configuration capable of providing excellent lubrication oil retaining function and initial break-in property as well as capable of being machined easily. The treatment surface of the cylinder liner has a plateau configuration providing a surface roughness Rz of 0.8 to 5.9 ?m, and the plateau configuration is defined under DIN4776 by a reduced peak height Rpk of not more than 0.64 ?m, a core roughness depth Rk of 0.05 to 1.8 ?m, and a reduced valley depth Rvk of 0.15 to 3.3 ?m. For grinding to the surface, a honing machine employs a grindstone containing metal bonded diamond grains at high density. Diamond grain size is not less than 4000.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: June 13, 2006
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventors: Yoshiki Ishikawa, Fujio Anzai
  • Patent number: 7044472
    Abstract: A combined steel oil control ring is provided which has steel side rails and a steel spacer expander. The spacer expander includes ear portions for contacting the side rails. The ear portions are substantially equally spaced with respect to each other along the internal circumferential portion of the spacer expander. The ear portions have radially external circumferential surfaces adapted to press the side rails radially outwardly by using the resilient force caused by the spacer expander. The spacer expander has up-and-down contours formed circumferentially along the radially external circumferential surface, for preventing the side rails from circumferentially rotating relatively to the spacer expander. The up-and-down contours each include at least two axially extending groove regions and at least three axially extending flat regions. The groove regions and flat regions are dimensioned to extend the life span of the contours and the dies.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: May 16, 2006
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventors: Akira Takahashi, Kazutomo Takahashi
  • Patent number: 7024982
    Abstract: A combination of piston and piston ring includes a piston having a piston ring groove in which at least the groove portion of the piston is made of steel, a piston ring made of cast iron and fitted into the piston ring groove, and a hard coat film formed to at least an outer peripheral sliding surface of the piston ring.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: April 11, 2006
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventors: Takeshi Aizawa, Manabu Kishida, Makoto Kajiwara
  • Publication number: 20060073065
    Abstract: An iron based sintered body suitable for being enveloped in a light metal alloy such as an aluminum alloy by casting, and a method for producing the same. A mixed powder is prepared by mixing an iron based powder, a copper powder and a graphite powder blended so that the Cu content and the C content are 5 to 40% by mass and 0.5 to 2.5% by mass, respectively, in the mixed powder. A lubricant powder and a fine particle powder for improving machinability may be further added in the mixed powder. Then, the mixed powder is filled into a mold formed to a green compact, and is sintered into a sintered body so that the sintered body has a desired average thermal expansion coefficient. The surface of the sintered body may be adjusted to have a surface roughness Rz of 10 to 100 ?m optionally by applying a shot blast treatment or by a shot blast treatment and an additional steam treatment.
    Type: Application
    Filed: November 17, 2005
    Publication date: April 6, 2006
    Applicants: NIPPON PISTON RING CO., LTD., FUJI JUKOGYO KABUSHIKI KAISHA
    Inventors: Hiroshi Takiguchi, Teruyuki Oda
  • Patent number: 7014677
    Abstract: The object of the invention is to provide an iron based sintered body suitable for being enveloped in light metal alloy such as an aluminum alloy by casting, and a method for producing the same. A mixed powder is prepared by mixing an iron based powder, a copper powder and a graphite powder blended so that the Cu content and the C content are 5 to 40% by mass and 0.5 to 2.5% by mass, respectively, in the mixed powder. A lubricant powder and a fine particle powder for improving machinability may be further added in the mixed powder. Then, the mixed powder is filled into a mold formed to a green compact, and is sintered into a sintered body so that the sintered body has a desired average thermal expansion coefficient. The surface of the sintered body may be adjusted to have a surface roughness Rz of 10 to 100 ?m optionally by applying a shot blast treatment or by a shot blast treatment and an additional steam treatment.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: March 21, 2006
    Assignees: Nippon Piston Ring Co., Ltd., Fuji Jukogyo Kabushiki Kaisha
    Inventors: Hiroshi Takiguchi, Teruyuki Oda
  • Publication number: 20050193861
    Abstract: 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 ?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 ?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.
    Type: Application
    Filed: March 3, 2005
    Publication date: September 8, 2005
    Applicants: Nippon Piston Ring Co., Ltd., Honda Motor Co., Ltd.
    Inventors: Kenichi Sato, Arata Kakiuchi, Teruo Takahashi, Tomoki Okita, Masahiro Takehana
  • Patent number: 6860485
    Abstract: The present invention provides a piston ring comprising a piston ring main body and an expander ring arranged on an inner peripheral surface thereof, the expander ring comprising two oil expander rings, one of which is housed in a space in a spiral of the other. The expander ring is formed so that the pressing force in the diameter expanding direction is larger in a high temperature state than in a low temperature state. The expander comprises two different kinds of expander members. One of these expander members has the same functions as those of a conventional expander, and the other is a member in which there occurs a change in tension in the diametral direction with temperature. As a result, the pressing force of the master expander member having the same effects as those of the conventional expander is made variable.
    Type: Grant
    Filed: March 21, 2003
    Date of Patent: March 1, 2005
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventors: Tetsuo Masuyama, Nobuyuki Matsushima
  • Patent number: 6852008
    Abstract: A method and apparatus for discharging work product from a device wherein a roller which is biased to push against the top of the work product cooperates with a stopper which engages the surface of the work product for displacing the work product, one-by-one from the device to a discharge chute.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: February 8, 2005
    Assignee: Nippon Piston Ring Co., Ltd.
    Inventor: Toshiaki Sato
  • Publication number: 20040187830
    Abstract: 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/cm3 and 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/cm3.
    Type: Application
    Filed: January 7, 2004
    Publication date: September 30, 2004
    Applicants: Nippon Piston Ring Co., Ltd., Honda Motor Co., Ltd.
    Inventors: Kenichi Sato, Arata Kakiuchi, Teruo Takahashi, Masao Ishida, Hiroyuki Oketani
  • Publication number: 20040182200
    Abstract: The object of the invention is to provide an iron based sintered body suitable for being enveloped in light metal alloy such as an aluminum alloy by casting, and a method for producing the same. A mixed powder is prepared by mixing an iron based powder, a copper powder and a graphite powder blended so that the Cu content and the C content are 5 to 40% by mass and 0.5 to 2.5% by mass, respectively, in the mixed powder. A lubricant powder and a fine particle powder for improving machinability may be further added in the mixed powder. Then, the mixed powder is filled into a mold formed to a green compact, and is sintered into a sintered body so that the sintered body has a desired average thermal expansion coefficient. The surface of the sintered body may be adjusted to have a surface roughness Rz of 10 to 100 &mgr;m optionally by applying a shot blast treatment or by a shot blast treatment and an additional steam treatment.
    Type: Application
    Filed: December 23, 2003
    Publication date: September 23, 2004
    Applicants: Nippon Piston Ring Co., Ltd., Fuji Jukogyo Kabushiki Kaisha
    Inventors: Hiroshi Takiguchi, Teruyuki Oda
  • Publication number: 20040126265
    Abstract: The object of the invention is to provide a porous metal structure body suitable for reinforcing a light metal alloy member such as an aluminum alloy member. A mixed powder containing a metallic powder is filled in a mold, and is molded into a shape having a single cavity or plural cavities in the inner portion while having a maximum thickness of 6 mm or less at the surface portion side. The molded powder body is sintered to form into the porous metal structure body having a porosity of 20 to 50% by volume at the portions except the cavities. It is preferable that the metallic powder sintered body having a porosity of exceeding 50% by volume is formed into the cavities by being monolithically integrated with the porous metal structure body. Consequently, a structure being lightweight, having a high mechanical strength and being excellent in handling performance while being excellent in impregnability can be obtained.
    Type: Application
    Filed: August 27, 2003
    Publication date: July 1, 2004
    Applicant: Nippon Piston Ring Co., Ltd.
    Inventor: Hiroshi Takiguchi