Patents by Inventor Yutaka Tajima
Yutaka Tajima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10176987Abstract: A SiC epitaxial wafer including: a SiC epitaxial layer that is formed on a SiC substrate having an off angle, wherein the surface density of triangular defects, in which a distance from a starting point to an opposite side in a horizontal direction is equal to or greater than (a thickness of the SiC epitaxial layer/tan(x))×90% and equal to or less than (the thickness of the SiC epitaxial layer/tan(x))×110%, in the SiC epitaxial layer is in the range of 0.05 pieces/cm2 to 0.5 pieces/cm2 (where x indicates the off angle).Type: GrantFiled: May 4, 2017Date of Patent: January 8, 2019Assignee: SHOWA DENKO K.K.Inventors: Akira Miyasaka, Yutaka Tajima, Yoshiaki Kageshima, Daisuke Muto, Kenji Momose
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Publication number: 20170233893Abstract: A SiC epitaxial wafer including: a SiC epitaxial layer that is formed on a SiC substrate having an off angle, wherein the surface density of triangular defects, in which a distance from a starting point to an opposite side in a horizontal direction is equal to or greater than (a thickness of the SiC epitaxial layer/tan(x))×90% and equal to or less than (the thickness of the SiC epitaxial layer/tan(x))×110%, in the SiC epitaxial layer is in the range of 0.05 pieces/cm2 to 0.5 pieces/cm2 (where x indicates the off angle).Type: ApplicationFiled: May 4, 2017Publication date: August 17, 2017Applicant: SHOWA DENKO K.K.Inventors: Akira MIYASAKA, Yutaka TAJIMA, Yoshiaki KAGESHIMA, Daisuke MUTO, Kenji MOMOSE
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Patent number: 9679767Abstract: Provided is a method of manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a SiC substrate using a SiC-CVD furnace which is installed in a glove box. The method includes a SiC substrate placement step of placing the SiC substrate in the SiC-CVD furnace while circulating gas in the glove box.Type: GrantFiled: June 19, 2013Date of Patent: June 13, 2017Assignee: SHOWA DENKO K.K.Inventors: Akira Miyasaka, Yutaka Tajima, Yoshiaki Kageshima, Daisuke Muto, Kenji Momose
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Publication number: 20160208414Abstract: The method for producing an SiC epitaxial wafer according to the present invention includes: a step of vacuum baking a coated carbon-based material member at a degree of vacuum of 2.0×10?3 Pa or less in a dedicated vacuum baking furnace; a step of installing the coated carbon-based material member in an epitaxial wafer manufacturing apparatus; and a step of placing an SiC substrate in the epitaxial wafer manufacturing apparatus and epitaxially growing an SiC epitaxial film on the SiC substrate.Type: ApplicationFiled: August 13, 2014Publication date: July 21, 2016Applicant: SHOWA DENKO K.K.Inventors: Michiya ODAWARA, Yutaka TAJIMA, Daisuke MUTO, Kenji MOMOSE
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Publication number: 20150162187Abstract: Provided is a method of manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a SiC substrate using a SiC-CVD furnace which is installed in a glove box. The method includes a SiC substrate placement step of placing the SiC substrate in the SiC-CVD furnace while circulating gas in the glove box.Type: ApplicationFiled: June 19, 2013Publication date: June 11, 2015Applicant: SHOWA DENKO K.K.Inventors: Akira Miyasaka, Yutaka Tajima, Yoshiaki Kageshima, Daisuke Muto, Kenji Momose
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Publication number: 20140339571Abstract: A SiC epitaxial wafer obtained by forming a SiC epitaxial layer on a 4H—SiC single-crystal substrate that is tilted at an off-angle of 0.4° to 5°, wherein linear density of step bunchings, which are connected to shallow pits which are due to screw dislocation in the SiC epitaxial wafer, is 5 mm?1 or less.Type: ApplicationFiled: July 30, 2014Publication date: November 20, 2014Applicant: SHOWA DENKO K.K.Inventors: Kenji MOMOSE, Yutaka TAJIMA, Yasuyuki SAKAGUCHI, Michiya ODAWARA, Yoshihiko MIYASAKA
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Patent number: 8823015Abstract: Provided is a silicon carbide epitaxial wafer, the entire surface of which is free of step bunching. Also provided is a method for manufacturing said silicon carbide epitaxial wafer. The provided method for manufacturing a silicon carbide semiconductor device includes: a step wherein a 4H—SiC single-crystal substrate having an off-axis angle of 5° or less is polished until the lattice disorder layer on the surface of the substrate is 3 nm or less; a step wherein, in a hydrogen atmosphere, the polished substrate is brought to a temperature between 1400° C. and 1600° C. and the surface of the substrate is cleaned; a step wherein silicon carbide is epitaxially grown on the surface of the cleaned substrate as the amounts of SiH4 gas and C3H8 gas considered necessary for epitaxially growing silicon carbide are supplied simultaneously at a carbon-to-silicon concentration ratio between 0.7 and 1.Type: GrantFiled: August 25, 2010Date of Patent: September 2, 2014Assignee: Showa Denko K.K.Inventors: Kenji Momose, Yutaka Tajima, Yasuyuki Sakaguchi, Michiya Odawara, Yoshihiko Miyasaka
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Patent number: 8714136Abstract: In a direct fuel-injection engine equipped with a pentroof-shaped piston, cross-sectional shapes containing a piston central axis (Lp) of a cavity recessed in a central part of the piston having a top face with the height varying in the circumferential direction are set so as to be basically identical at each position in the circumferential direction (see broken line).Type: GrantFiled: December 12, 2008Date of Patent: May 6, 2014Assignee: Honda Motor Co., Ltd.Inventors: Kenichiro Ikeya, Nobuhiko Sasaki, Hiroshi Sono, Yukihisa Yamaya, Akihiro Yamaguchi, Yoshimasa Kaneko, Goichi Katayama, Yutaka Tajima
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Patent number: 8627798Abstract: A direct fuel-injection engine includes a piston, a cavity recessed in a central part of a top face of the piston, and a fuel injector. At a main injection collision point of a fuel-injection axis when main injection is performed while the piston is near top dead center, a main injection collision angle formed between its tangent and the fuel-injection axis is set at an obtuse angle. Fuel colliding with the main injection collision point is deflected towards a cavity open end side. At a secondary injection collision point of the fuel-injection axis when performing secondary injection with the piston is further from top dead center, a secondary injection collision angle formed between its tangent and the fuel-injection axis is set at one of a right angle and an acute angle. Fuel colliding with the secondary injection collision point is deflected primarily in the circumferential direction of the cavity.Type: GrantFiled: November 17, 2009Date of Patent: January 14, 2014Assignee: Honda Motor Co., Ltd.Inventors: Akihiro Yamaguchi, Yoshimasa Kaneko, Yukihisa Yamaya, Yutaka Tajima, Kenichiro Ikeya, Goichi Katayama, Nobuhiko Sasaki, Hiroshi Sono
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Patent number: 8474431Abstract: In a cross section in which squish flow from an outer peripheral part of a piston (13) toward a cavity (25) is large due to a width (W2) of a squish area (SA) being large and a squish clearance (C2) being small, a collision angle (?2) at which a fuel injection axis (Li2) collides with the cavity (25) is made large, whereas in a cross section in which squish flow is small due to the width of the squish area (SA) being small and the squish clearance being large, the collision angle at which a fuel injection axis collides with the cavity (25) is made small. This enables a tendency for fuel to flow out to the exterior of the cavity (25) in a cross section where the squish flow is small to be weakened, and a tendency for fuel to flow out to the exterior of the cavity (25) in a cross section where the squish flow is large to be strengthened, thereby making the conditions in which fuel and air are mixed uniform throughout the entire region of the cavity (25).Type: GrantFiled: April 3, 2008Date of Patent: July 2, 2013Assignee: Honda Motor Co., Ltd.Inventors: Hiroshi Sono, Tatsuya Uchimoto, Yukihisa Yamaya, Kenichiro Ikeya, Yutaka Tajima, Mitsuhiro Shibata, Nobuhiko Sasaki
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Patent number: 8418669Abstract: In an internal combustion engine having a pair of balancer shafts (53, 54), an engine torque is transmitted from a crank gear (28) to an oil pump gear (74) on a drive shaft (73) of an oil pump (71) via a first idler gear (84) and the first balancer shaft gear (64). The engine torque is also transmitted to a fuel pump (72) from the crank gear to a fuel pump gear (78) via the first idler gear and a second idler gear (86), and to the second balancer shaft gear (67) via the first idler gear and second idler gear. Alternatively, the engine torque may be transmitted to the fuel pump from the crank gear to the fuel pump gear via the first idler gear, second balancer shaft gear and second idler gear. As the oil pump gear is actuated by the crank gear via the first idler gear, the oil pump gear is not subjected to the loading caused by the balancer shaft, and hence can be made of a compact and light-weight gear.Type: GrantFiled: February 10, 2011Date of Patent: April 16, 2013Assignee: Honda Motor Co., Ltd.Inventors: Goichi Katayama, Yoshihiro Fujiyoshi, Yutaka Tajima, Shoichi Yamamoto
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Publication number: 20120146056Abstract: Provided is a silicon carbide epitaxial wafer, the entire surface of which is free of step bunching. Also provided is a method for manufacturing said silicon carbide epitaxial wafer. The provided method for manufacturing a silicon carbide semiconductor device includes: a step wherein a 4H—SiC single-crystal substrate having an off-axis angle of 5° or less is polished until the lattice disorder layer on the surface of the substrate is 3 nm or less; a step wherein, in a hydrogen atmosphere, the polished substrate is brought to a temperature between 1400° C. and 1600° C. and the surface of the substrate is cleaned; a step wherein silicon carbide is epitaxially grown on the surface of the cleaned substrate as the amounts of SiH4 gas and C3H8 gas considered necessary for epitaxially growing silicon carbide are supplied simultaneously at a carbon-to-silicon concentration ratio between 0.7 and 1.Type: ApplicationFiled: August 25, 2010Publication date: June 14, 2012Applicant: SHOWA DENKO K.K.Inventors: Kenji Momose, Yutaka Tajima, Yasuyuki Sakaguchi, Michiya Odawara, Yoshihiko Miyasaka
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Patent number: 8056532Abstract: In a direct fuel injection diesel engine having a piston with a pentroof-shaped top face, with regard to a pentroof-shaped piston (13) with a cavity (25) recessed in a central part of the top face, a radial width S of a squish area (26) formed between an outer peripheral part of the top face and a lower face of a cylinder head (14) changes in the circumferential direction of the piston (13). By setting a squish clearance H large for a portion where the radial width S of the squish area (26) is large and setting the squish clearance H small for a portion where the radial width S of the squish area (26) is small, more specifically, by setting S/H so that it is constant in the circumferential direction, it is possible to make the strength of the squish flow uniform in the circumferential direction of the piston, thus promoting the mixing of air and fuel and reducing harmful exhaust components.Type: GrantFiled: April 11, 2007Date of Patent: November 15, 2011Assignee: Honda Motor Co., Ltd.Inventors: Mitsuhiro Shibata, Hiroshi Sono, Nobuhiko Sasaki, Tatsuya Uchimoto, Kenichiro Ikeya, Yutaka Tajima, Yukihisa Yamaya
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Publication number: 20110209680Abstract: In an internal combustion engine having a pair of balancer shafts (53, 54), an engine torque is transmitted from a crank gear (28) to an oil pump gear (74) on a drive shaft (73) of an oil pump (71) via a first idler gear (84) and the first balancer shaft gear (64). The engine torque is also transmitted to a fuel pump (72) from the crank gear to a fuel pump gear (78) via the first idler gear and a second idler gear (86), and to the second balancer shaft gear (67) via the first idler gear and second idler gear. Alternatively, the engine torque may be transmitted to the fuel pump from the crank gear to the fuel pump gear via the first idler gear, second balancer shaft gear and second idler gear. As the oil pump gear is actuated by the crank gear via the first idler gear, the oil pump gear is not subjected to the loading caused by the balancer shaft, and hence can be made of a compact and light-weight gear.Type: ApplicationFiled: February 10, 2011Publication date: September 1, 2011Applicant: HONDA MOTOR CO., LTD.Inventors: Goichi KATAYAMA, Yoshihiro Fujiyoshi, Yutaka Tajima, Shoichi Yamamoto
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Patent number: 7992536Abstract: In a direct fuel injection diesel engine equipped with a pentroof-shaped piston, when fuel is injected into a cavity (25) recessed in a central part of a piston (13), for which the height of a top face changes in the circumferential direction, from a fuel injection point (Oinj) of a fuel injector disposed on a piston central axis along a plurality of fuel injection axes (Li1,Li2), if a cross-section of the cavity (25) passing along the fuel injection axis (Li1,Li2) is defined as a fuel injection cross-section (Sn), a cross-sectional shape (see shaded portion) of the cavity (25) defined by first to third specific points (An, Bn, Cn) on the fuel injection cross-section (Sn) is set so as to be substantially equal for each fuel injection cross-section (Sn). By so doing, the conditions in which fuel and air are mixed in each fuel injection cross-section (Sn) can be made uniform, the engine output can be improved, and harmful exhaust substances can be reduced.Type: GrantFiled: April 11, 2007Date of Patent: August 9, 2011Assignee: Honda Motor Co., Ltd.Inventors: Kenichiro Ikeya, Yukihisa Yamaya, Nobuhiko Sasaki, Tatsuya Uchimoto, Yutaka Tajima, Mitsuhiro Shibata, Hiroshi Sono
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Patent number: 7861685Abstract: In a direct fuel injection diesel engine equipped with a pentroof-shaped piston, a collision angle (?) at which fuel injected in a direction in which the height of the top face of a piston (13) is high collides with a cavity (25) is set larger than a collision angle (?) at which fuel injected in a direction in which the height of the top face of the piston (13) is low collides with the cavity (25).Type: GrantFiled: June 7, 2007Date of Patent: January 4, 2011Assignee: Honda Motor Co., Ltd.Inventors: Hiroshi Sono, Nobuhiko Sasaki, Tatsuya Uchimoto, Kenichiro Ikeya, Yutaka Tajima, Mitsuhiro Shibata, Yukihisa Yamaya
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Publication number: 20100258078Abstract: In a direct fuel-injection engine equipped with a pentroof-shaped piston, cross-sectional shapes containing a piston central axis (Lp) of a cavity recessed in a central part of the piston having a top face with the height varying in the circumferential direction are set so as to be basically identical at each position in the circumferential direction (see broken line).Type: ApplicationFiled: December 12, 2008Publication date: October 14, 2010Applicant: HONDA MOTOR CO., LTD.Inventors: Kenichiro Ikeya, Nobuhiko Sasaki, Hiroshi Sono, Yukihisa Yamaya, Akihiro Yamaguchi, Yoshimasa Kaneko, Goichi Katayama, Yutaka Tajima
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Publication number: 20100186709Abstract: In a direct fuel injection diesel engine equipped with a pentroof-shaped piston, when fuel is injected into a cavity (25) recessed in a central part of a piston (13), for which the height of a top face changes in the circumferential direction, from a fuel injection point (Oinj) of a fuel injector disposed on a piston central axis along a plurality of fuel injection axes (Li1,Li2), if a cross-section of the cavity (25) passing along the fuel injection axis (Li1,Li2) is defined as a fuel injection cross-section (Sn), a cross-sectional shape (see shaded portion) of the cavity (25) defined by first to third specific points (An, Bn, Cn) on the fuel injection cross-section (Sn) is set so as to be substantially equal for each fuel injection cross-section (Sn). By so doing, the conditions in which fuel and air are mixed in each fuel injection cross-section (Sn) can be made uniform, the engine output can be improved, and harmful exhaust substances can be reduced.Type: ApplicationFiled: April 11, 2007Publication date: July 29, 2010Applicant: HONDA MOTOR CO., LTD.Inventors: Kenichiro Ikeya, Yukihisa Yamaya, Nobuhiko Sasaki, Tatsuya Uchimoto, Yutaka Tajima, Mitsuhiro Shibata, Hiroshi Sono
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Publication number: 20100147260Abstract: A direct fuel-injection engine includes a piston, a cavity recessed in a central part of a top face of the piston, and a fuel injector. At a main injection collision point of a fuel-injection axis when main injection is performed while the piston is near top dead center, a main injection collision angle formed between its tangent and the fuel-injection axis is set at an obtuse angle. Fuel colliding with the main injection collision point is deflected towards a cavity open end side. At a secondary injection collision point of the fuel-injection axis when performing secondary injection with the piston is further from top dead center, a secondary injection collision angle formed between its tangent and the fuel-injection axis is set at one of a right angle and an acute angle. Fuel colliding with the secondary injection collision point is deflected primarily in the circumferential direction of the cavity.Type: ApplicationFiled: November 17, 2009Publication date: June 17, 2010Applicant: HONDA MOTOR CO., LTD.Inventors: Akihiro YAMAGUCHI, Yoshimasa KANEKO, Yukihisa YAMAYA, Yutaka TAJIMA, Kenichiro IKEYA, Goichi KATAYAMA, Nobuhiko SASAKI, Hiroshi SONO
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Publication number: 20100108022Abstract: In a cross section in which squish flow from an outer peripheral part of a piston (13) toward a cavity (25) is large due to a width (W2) of a squish area (SA) being large and a squish clearance (C2) being small, a collision angle (?2) at which a fuel injection axis (Li2) collides with the cavity (25) is made large, whereas in a cross section in which squish flow is small due to the width of the squish area (SA) being small and the squish clearance being large, the collision angle at which a fuel injection axis collides with the cavity (25) is made small. This enables a tendency for fuel to flow out to the exterior of the cavity (25) in a cross section where the squish flow is small to be weakened, and a tendency for fuel to flow out to the exterior of the cavity (25) in a cross section where the squish flow is large to be strengthened, thereby making the conditions in which fuel and air are mixed uniform throughout the entire region of the cavity (25).Type: ApplicationFiled: April 3, 2008Publication date: May 6, 2010Inventors: Hiroshi Sono, Tatsuya Uchimoto, Yukihisa Yamaya, Kenichiro Ikeya, Yutaka Tajima, Mitsuhiro Shibata, Nobuhiko Sasaki