Patents by Inventor Takafumi Arakawa
Takafumi Arakawa 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: 11242813Abstract: Transmission shocks and idling defects such as engine racing and rough idling due to aging of a throttle opening area are prevented from occurring. An internal combustion engine control apparatus for controlling an internal combustion engine that has an air flow rate sensor for measuring a rate of air represented as an actual air rate, the air flowing into a cylinder, and a throttle valve for adjusting the rate of air, includes a throttle valve controlling section for controlling a throttle opening of the throttle valve to reach a preset throttle opening set depending on a target air rate for realizing a demand torque, and a throttle opening correcting section for correcting the preset throttle opening on the basis of the target air rate upon fuel cutoff that stops a fuel from being supplied to the internal combustion engine and of an actual air rate measured by the air flow rate sensor.Type: GrantFiled: July 5, 2018Date of Patent: February 8, 2022Assignee: Hitachi Astemo, Ltd.Inventors: Yoichi Iihoshi, Toshio Hori, Takafumi Arakawa, Haoyun Shi
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Patent number: 11067041Abstract: A novel control device for an internal combustion engine capable of highly accurately estimating an EGR amount (rate) during the transient state is provided. A first EGR rate is determined using, as an input, a detection signal of an EGR sensor provided on the downstream side of a throttle valve which adjusts the flow rate of a mixed gas of air and EGR gas flowing through an intake pipe, a second EGR rate is estimated by calculating a predetermined equation using, as an input, at least a detection signal of an air flow sensor and an EGR valve opening degree sensor, a third EGR rate is determined by carrying out delay processing on the second EGR rate corresponding to a response delay of the EGR sensor, and the second EGR rate is subjected to learning correction by reflecting a difference between the third EGR rate and the first EGR rate.Type: GrantFiled: December 27, 2017Date of Patent: July 20, 2021Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Takafumi Arakawa, Yoichi Iihoshi, Kunihiko Suzuki, Toshio Hori
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Publication number: 20210087992Abstract: Transmission shocks and idling defects such as engine racing and rough idling due to aging of a throttle opening area are prevented from occurring. An internal combustion engine control apparatus for controlling an internal combustion engine that has an air flow rate sensor for measuring a rate of air represented as an actual air rate, the air flowing into a cylinder, and a throttle valve for adjusting the rate of air, includes a throttle valve controlling section for controlling a throttle opening of the throttle valve to reach a preset throttle opening set depending on a target air rate for realizing a demand torque, and a throttle opening correcting section for correcting the preset throttle opening on the basis of the target air rate upon fuel cutoff that stops a fuel from being supplied to the internal combustion engine and of an actual air rate measured by the air flow rate sensor.Type: ApplicationFiled: July 5, 2018Publication date: March 25, 2021Inventors: Yoichi IIHOSHI, Toshio HORI, Takafumi ARAKAWA, Haoyun SHI
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Patent number: 10920683Abstract: Provided is a novel control device of an internal combustion engine capable of estimating an EGR rate in a transient state with high accuracy. Thus, in the present invention, unit spaces are formed by dividing a reference space of the intake passage into a plurality of spaces along a streamline through which the gas mixture of the intake air and the EGR gas flows, a physical model based on an advection equation for estimating the EGR rate of the gas mixture is established so as to correspond to each of the unit spaces, and the EGR rate at which the gas mixture flows into the combustion chamber is estimated by sequentially estimating the EGR rates of the unit spaces connected to head unit spaces from the head unit spaces by the physical model.Type: GrantFiled: June 4, 2018Date of Patent: February 16, 2021Assignee: Hitachi Automotive Systems, Ltd.Inventors: Takafumi Arakawa, Kunihiko Suzuki, Yoichi Iihoshi, Haoyun Shi, Toshio Hori, Yoshikuni Kurashima
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Patent number: 10840238Abstract: A semiconductor device has a semiconductor substrate including an IGBT region operating as an IGBT provided by an emitter layer, a base layer, a drift layer and a collector layer, and a diode region operating as a diode and provided by an anode layer, the drift layer and a cathode layer. The semiconductor substrate further includes a guard ring of a second conduction type, provided in a surface layer of the drift layer in a peripheral region surrounding a device region where the IGBT region and the diode region are adjacent to each other. The cathode layer and the guard ring are positioned such as to satisfy L/d?1.5, where L is a minimum value of a distance between the cathode layer and the guard ring as projected to a plane parallel to a surface of the semiconductor substrate, and d is a thickness of the semiconductor substrate.Type: GrantFiled: May 24, 2017Date of Patent: November 17, 2020Assignee: DENSO CORPORATIONInventors: Takafumi Arakawa, Shigeki Takahashi
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Publication number: 20200200100Abstract: There is provided a novel throttle valve controller device for an internal combustion engine that is capable of accurately producing a target torque for the internal combustion engine. The present invention includes a target fresh intake air flow rate calculating section that calculates a target fresh intake air flow rate passing through a throttle valve, an EGR gas flow rate calculating section that calculates an estimated EGR gas flow rate passing through the throttle valve, a target throttle intake gas flow rate calculating section that calculates a target intake gas flow rate passing through the throttle valve on the basis of the target fresh intake air flow rate and the estimated EGR gas flow rate, and a target throttle valve opening calculating section that calculates a target throttle valve opening from the target intake gas flow rate.Type: ApplicationFiled: May 11, 2018Publication date: June 25, 2020Inventors: Haoyun SHI, Takafumi ARAKAWA, Yoichi IIHOSHI, Kunihiko SUZUKI, Toshio HORI, Yoshikuni KURASHIMA
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Publication number: 20200123989Abstract: Provided is a novel control device of an internal combustion engine capable of estimating an EGR rate in a transient state with high accuracy. Thus, in the present invention, unit spaces are formed by dividing a reference space of the intake passage into a plurality of spaces along a streamline through which the gas mixture of the intake air and the EGR gas flows, a physical model based on an advection equation for estimating the EGR rate of the gas mixture is established so as to correspond to each of the unit spaces, and the EGR rate at which the gas mixture flows into the combustion chamber is estimated by sequentially estimating the EGR rates of the unit spaces connected to head unit spaces from the head unit spaces by the physical model.Type: ApplicationFiled: June 4, 2018Publication date: April 23, 2020Inventors: Takafumi ARAKAWA, Kunihiko SUZUKI, Yoichi IIHOSHI, Haoyun SHI, Toshio HORI, Yoshikuni KURASHIMA
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Publication number: 20190368448Abstract: A novel control device for an internal combustion engine capable of highly accurately estimating an EGR amount (rate) during the transient state is provided. A first EGR rate is determined using, as an input, a detection signal of an EGR sensor provided on the downstream side of a throttle valve which adjusts the flow rate of a mixed gas of air and EGR gas flowing through an intake pipe, a second EGR rate is estimated by calculating a predetermined equation using, as an input, at least a detection signal of an air flow sensor and an EGR valve opening degree sensor, a third EGR rate is determined by carrying out delay processing on the second EGR rate corresponding to a response delay of the EGR sensor, and the second EGR rate is subjected to learning correction by reflecting a difference between the third EGR rate and the first EGR rate.Type: ApplicationFiled: December 27, 2017Publication date: December 5, 2019Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Takafumi ARAKAWA, Yoichi IIHOSHI, Kunihiko SUZUKI, Toshio HORI
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Publication number: 20190096878Abstract: semiconductor device has a semiconductor substrate including an IGBT region operating as an IGBT provided by an emitter layer, a base layer, a drift layer and a collector layer, and a diode region operating as a diode and provided by an anode layer, the drift layer and a cathode layer. The semiconductor substrate further includes a guard ring of a second conduction type, provided in a surface layer of the drift layer in a peripheral region surrounding a device region where the IGBT region and the diode region are adjacent to each other. The cathode layer and the guard ring are positioned such as to satisfy L/d?1.5, where L is a minimum value of a distance between the cathode layer and the guard ring as projected to a plane parallel to a surface of the semiconductor substrate, and d is a thickness of the semiconductor substrate.Type: ApplicationFiled: May 24, 2017Publication date: March 28, 2019Inventors: Takafumi ARAKAWA, Shigeki TAKAHASHI
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Patent number: 9863999Abstract: A circuit for inspecting a semiconductor device includes: the semiconductor device that is an object to be inspected and includes a diode; a protection element that is connected in series with the semiconductor device and includes a protection diode having higher breakdown resistance than the diode; a switch that includes a switching element connected in series with the semiconductor device and the protection element; and a coil that provides a loop path together with the semiconductor device and the protection element when the switching element is turned off. Even when the semiconductor device including the diode is broken, an inspection device is restricted from being damaged.Type: GrantFiled: June 23, 2015Date of Patent: January 9, 2018Assignee: DENSO CORPORATIONInventors: Masanori Miyata, Takafumi Arakawa
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Publication number: 20170131344Abstract: A circuit for inspecting a semiconductor device includes: the semiconductor device that is an object to be inspected and includes a diode; a protection element that is connected in series with the semiconductor device and includes a protection diode having higher breakdown resistance than the diode; a switch that includes a switching element connected in series with the semiconductor device and the protection element; and a coil that provides a loop path together with the semiconductor device and the protection element when the switching element is turned off. Even when the semiconductor device including the diode is broken, an inspection device is restricted from being damaged.Type: ApplicationFiled: June 23, 2015Publication date: May 11, 2017Applicant: DENSO CORPORATIONInventors: Masanori MIYATA, Takafumi ARAKAWA
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Patent number: 8056707Abstract: Provided are a heat resistant laminated conveyor belt and manufacturing method thereof by which a belt surface pressure when a liner and corrugated core paper are pressed and bonded together can be increased to thereby enhance a bonding performance. The heat resistant laminated conveyor belt comprises a belt core layer 11 made by a heat resistant non-metallic fiber substrate being impregnated with a fluororesin dispersion and then dried and sintered and a surface layer 13 (plain weave wire, etc., for example) formed on the belt core layer 11 via an adhesive layer 12 made by a fluororesin film, the surface layer having a fabric structure using an element wire or wires made of a ferrous metal or having a structure in which the element wire or wires are arranged together.Type: GrantFiled: May 16, 2005Date of Patent: November 15, 2011Assignees: Mitsubishi Heavy Industries Printing & Packaging Machinery, Ltd., Chukoh Chemical Industries, Ltd.Inventors: Hiroshi Ishibuchi, Takashi Nitta, Hideo Imazato, Takafumi Arakawa
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Publication number: 20090014122Abstract: Provided are a heat resistant laminated conveyor belt and manufacturing method thereof by which a belt surface pressure when a liner and corrugated core paper are pressed and bonded together can be increased to thereby enhance a bonding performance. The heat resistant laminated conveyor belt comprises a belt core layer 11 made by a heat resistant non-metallic fiber substrate being impregnated with a fluororesin dispersion and then dried and sintered and a surface layer 13 (plain weave wire, etc., for example) formed on the belt core layer 11 via an adhesive layer 12 made by a fluororesin film, the surface layer having a fabric structure using an element wire or wires made of a ferrous metal or having a structure in which the element wire or wires are arranged together.Type: ApplicationFiled: May 16, 2005Publication date: January 15, 2009Inventors: Hiroshi Ishibuchi, Takashi Nitta, Hideo Imazato, Takafumi Arakawa
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Patent number: 7037788Abstract: By improving profile of impurity concentration in a channel portion of an FET or an IGBT of a trench gate type, variation of threshold value is lessened, and a destruction caused by current concentration is prevented while suppressing deterioration of cut-off characteristics. An island of a base region of p-type is formed in a semiconductor substrate of n-type by carrying out high acceleration ion implantation twice followed by annealing, so that the impurity concentration profile in a channel portion changes gradually in a depth direction. Accordingly, it is possible to lessen variation of the threshold value and to reduce pinch resistance while at the same time improving sub-threshold voltage coefficient and conductance characteristics.Type: GrantFiled: February 26, 2004Date of Patent: May 2, 2006Assignee: Denso CorporationInventors: Hiroyasu Ito, Masatoshi Kato, Takafumi Arakawa
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Publication number: 20050090060Abstract: A trench-gate type transistor has a gate insulating film formed on an inner wall of a trench. The gate insulating film includes a first portion located on a wall of the trench and a second portion located on upper and bottom portions of the trench. The first portion includes a first oxide film, a nitride film, and a second oxide film. The second portion includes only an oxide film and is thicker than the first portion. Accordingly, electric field concentration on upper and lower corner portions of the trench can be reduced to improve the withstand voltage. In addition, and end of the trench may have an insulation layer that is thicker than the first portion.Type: ApplicationFiled: October 28, 2004Publication date: April 28, 2005Inventors: Takaaki Aoki, Yutaka Tomatsu, Akira Kuroyanagi, Mikimasa Suzuki, Hajime Soga, Takafumi Arakawa, Yukio Tsuzuki
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Patent number: 6864532Abstract: A trench-gate type transistor has a gate insulating film formed on an inner wall of a trench. The gate insulating film includes a first portion located on a wall of the trench and a second portion located on upper and bottom portions of the trench. The first portion includes a first oxide film, a nitride film, and a second oxide film. The second portion includes only an oxide film and is thicker than the first portion. Accordingly, electric field concentration on upper and lower corner portions of the trench can be reduced to improve the withstand voltage. In addition, and end of the trench may have an insulation layer that is thicker than the first portion.Type: GrantFiled: June 20, 2002Date of Patent: March 8, 2005Assignee: Denso CorporationInventors: Takaaki Aoki, Akira Kuroyanagi, Mikimasa Suzuki, Takafumi Arakawa, Yukio Tsuzuki
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Publication number: 20040166637Abstract: By improving profile of impurity concentration in a channel portion of an FET or an IGBT of a trench gate type, variation of threshold value is lessened, and a destruction caused by current concentration is prevented while suppressing deterioration of cut-off characteristics. An island of a base region of p-type is formed in a semiconductor substrate of n-type by carrying out high acceleration ion implantation twice followed by annealing, so that the impurity concentration profile in a channel portion changes gradually in a depth direction. Accordingly, it is possible to lessen variation of the threshold value and to reduce pinch resistance while at the same time improving sub-threshold voltage coefficient and conductance characteristics.Type: ApplicationFiled: February 26, 2004Publication date: August 26, 2004Inventors: Hiroyasu Ito, Masatoshi Kato, Takafumi Arakawa
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Patent number: 6624044Abstract: First, a trench of a semiconductor substrate is filled with a polysilicon film deposited on the surface of the semiconductor substrate. A selective thin film having etching selectivity with respect to the polysilicon film is formed on the polysilicon film. Then, the selective thin film is etched (etched back) so that a part of the selective thin film remains in a depression of the polysilicon film, as a self-aligning mask. The polysilicon film is further etched with the self-aligning mask, thereby forming a polysilicon embedded layer in the trench with a flat surface.Type: GrantFiled: May 11, 2001Date of Patent: September 23, 2003Assignee: Denso CorporationInventors: Hiroyasu Ito, Takafumi Arakawa, Masatoshi Kato
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Publication number: 20020167046Abstract: A trench-gate type transistor has a gate insulating film formed on an inner wall of a trench. The gate insulating film includes a first portion located on a wall of the trench and a second portion located on upper and bottom portions of the trench. The first portion includes a first oxide film, a nitride film, and a second oxide film. The second portion includes only an oxide film and is thicker than the first portion. Accordingly, electric field concentration on upper and lower corner portions of the trench can be reduced to improve the withstand voltage. In addition, and end of the trench may have an insulation layer that is thicker than the first portion.Type: ApplicationFiled: June 20, 2002Publication date: November 14, 2002Inventors: Takaaki Aoki, Yutaka Tomatsu, Akira Kuroyanagi, Mikimasa Suzuki, Hajime Soga, Takafumi Arakawa, Yukio Tsuzuki
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Patent number: 6448139Abstract: A semiconductor substrate has a trench for forming a gate insulation film and a gate electrode therein, or an insulated isolation isolating a semiconductor element like a transistor from other elements. The trench is formed by anisotropic dry etching. After that, a shape of the trench is improved so that a bottom portion and an opening portion are rounded or tapered by a wet process using a mixed solution containing hydrofluoric acid and nitric acid. By modifying the shape of the trench, electrical characteristics of the trench are improved. For example, an oxide film formed in the trench has high quality, whereby a gate withstanding voltage is improved.Type: GrantFiled: June 7, 2001Date of Patent: September 10, 2002Assignee: Denso CorporationInventors: Hiroyasu Ito, Takafumi Arakawa, Masatoshi Kato