Patents by Inventor Hirokuni Tomita
Hirokuni Tomita 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: 9534589Abstract: Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.Type: GrantFiled: July 2, 2013Date of Patent: January 3, 2017Assignees: DENSO CORPORATION, NIPPON SOKEN, INC.Inventors: Shinobu Oikawa, Hirokuni Tomita, Takehiko Kato
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Patent number: 9404481Abstract: Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.Type: GrantFiled: November 17, 2015Date of Patent: August 2, 2016Assignees: DENSO CORPORATION, NIPPON SOKEN, INC.Inventors: Shinobu Oikawa, Hirokuni Tomita, Takehiko Kato
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Publication number: 20160069333Abstract: Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.Type: ApplicationFiled: November 17, 2015Publication date: March 10, 2016Inventors: Shinobu OIKAWA, Hirokuni TOMITA, Takehiko KATO
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Publication number: 20140010687Abstract: Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.Type: ApplicationFiled: July 2, 2013Publication date: January 9, 2014Inventors: Shinobu OIKAWA, Hirokuni TOMITA, Takehiko KATO
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Publication number: 20110315909Abstract: A constant-residual-pressure valve is disposed in a communication passage connecting a high-pressure fuel passage through which pressurized fuel flows with a low-pressure fuel passage through which the fuel flows toward a high-pressure pump. The constant-residual-pressure valve includes a valve body, a spring, and a spring stopper. The valve body can sit on a valve seat formed in an inner passage. The spring biases the valve body toward the valve seat. The spring stopper has a downstream-orifice of which flow passage area is smaller than that of a passage upstream of the valve seat. Thereby, cavitation between the valve body and the valve seat is less generated.Type: ApplicationFiled: June 29, 2011Publication date: December 29, 2011Applicants: NIPPON SOKEN, INC., DENSO CORPORATIONInventors: Shinobu OIKAWA, Hirokuni Tomita
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Patent number: 7784492Abstract: In a direction control valve, a bottom face of an insertion hole of a first movable member is at a predetermined distance from a second movable member with respect to a first axial direction when communication between a first communication switching port and a communication object port is made and communication between a second communication switching port and the communication object port is broken. The bottom face contacts and pushes the second movable member in a second axial direction opposite to the first axial direction after the first movable member moves in the second axial direction by the predetermined distance while the first and second movable members move in the second axial direction to switch a port communicating with the communication object port from the first communication switching port to the second communication switching port.Type: GrantFiled: July 28, 2006Date of Patent: August 31, 2010Assignees: Denso Corporation, Nippon Soken, Inc.Inventors: Yoshihisa Yamamoto, Hirokuni Tomita, Yoshihiro Hotta, Yoshifumi Wakisaka, Kiyomi Kawamura
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Publication number: 20090159048Abstract: An injected fuel pressure boosting device provided with a large diameter piston, a medium diameter piston, and a small diameter piston. A high pressure chamber filled at high pressure at all times is formed at the outer end of the medium diameter pistons, while a pressure boosting chamber is formed at the outer end of the small diameter piston. A pressure control chamber is formed on the end face of the large diameter piston on the small diameter piston side. When high pressure fuel is supplied to the pressure control chamber, the large diameter piston moves to the medium diameter piston side, that is, the pressure boosting preparation position. At this time, the leaked fuel outflow port is closed by the end face of the large diameter piston.Type: ApplicationFiled: March 20, 2007Publication date: June 25, 2009Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON SOKEN, INC, DENSO CORPORATIONInventors: Takafumi Yamada, Yoshimasa Watanabe, Hirokuni Tomita, Yoshihisa Yamamoto
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Publication number: 20070023092Abstract: In a direction control valve, a bottom face of an insertion hole of a first movable member is at a predetermined distance from a second movable member with respect to a first axial direction when communication between a first communication switching port and a communication object port is made and communication between a second communication switching port and the communication object port is broken. The bottom face contacts and pushes the second movable member in a second axial direction opposite to the first axial direction after the first movable member moves in the second axial direction by the predetermined distance while the first and second movable members move in the second axial direction to switch a port communicating with the communication object port from the first communication switching port to the second communication switching port.Type: ApplicationFiled: July 28, 2006Publication date: February 1, 2007Applicants: DENSO CORPORATION, NIPPON SOKEN. INC.Inventors: Yoshihisa Yamamoto, Hirokuni Tomita, Yoshihiro Hotta, Yoshifumi Wakisaka, Kiyomi Kawamura
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Patent number: 6752374Abstract: In an electromagnetic valve, after a solenoid assembly, in which a housing surrounds an outer circumference of a solenoid composed of a coil and a bobbin and a resin connector is formed on the housing by injection molding, and a valve body assembly, in which a valve body member is slidably housed to move reciprocatingly in a valve case cylindrical hollow of a valve case member, are independently sub assembled, the valve body assembly is integrated with the solenoid assembly in such a manner that the valve case member is axially inserted into a cylindrical hollow of the bobbin and, then, an axial end of the housing is fixed to an outer circumference of the valve case member by crimping. Accordingly, if a malfunction of a component part occurs during manufacturing processes, less number of component parts are rejected as failure.Type: GrantFiled: July 19, 2002Date of Patent: June 22, 2004Assignees: Nippon Soken, Inc., Denso CorporationInventors: Yutaka Miyamoto, Shigeiku Enomoto, Hirokuni Tomita, Yukihiro Shinohara
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Publication number: 20030020038Abstract: In an electromagnetic valve, after a solenoid assembly, in which a housing surrounds an outer circumference of a solenoid composed of a coil and a bobbin and a resin connector is formed on the housing by injection molding, and a valve body assembly, in which a valve body member is slidably housed to move reciprocatingly in a valve case cylindrical hollow of a valve case member, are independently sub assembled, the valve body assembly is integrated with the solenoid assembly in such a manner that the valve case member is axially inserted into a cylindrical hollow of the bobbin and, then, an axial end of the housing is fixed to an outer circumference of the valve case member by crimping. Accordingly, if a malfunction of a component part occurs during manufacturing processes, less number of component parts are rejected as failure.Type: ApplicationFiled: July 19, 2002Publication date: January 30, 2003Inventors: Yutaka Miyamoto, Shigeiku Enomoto, Hirokuni Tomita, Yukihiro Shinohara