Patents by Inventor Masami Niimi

Masami Niimi 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).

  • Starter for an internal combustion engine
    Patent number: 6838780
    Abstract: A starter for an internal combustion engine has a resistance ratio rM/rB equal to or less than 0.4, when rM represents a motor internal resistance and rB represents a battery internal resistance. Furthermore, the starter has a size ratio L/D equal to or less than 1.0, when L represents an axial length of the armature and D represents an outer diameter of the armature. Furthermore, a means for suppressing temperature rise is provided for the starter.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: January 4, 2005
    Assignee: Denso Corporation
    Inventors: Tsutomu Shiga, Masami Niimi, Masanori Ohmi
  • Electromagnetic switch and starter using the same
    Patent number: 6833778
    Abstract: An electromagnetic switch includes a contact holding member connected to a plunger in order to hold a first movable contact. The contact holding member is disposed outside a switch case covering a periphery of an excitation coil. A return spring pushes the plunger back in the opposite direction to a fixed iron core through the contact holding member when electric power supply to the excitation coil is stopped. The return spring is disposed outside the switch case. In this structure, a spring holding portion does not need to be disposed in the fixed iron core and the plunger. Therefore, an area where the fixed iron core attracts the plunger can be increased, so that an attraction force can be increased.
    Type: Grant
    Filed: March 9, 2004
    Date of Patent: December 21, 2004
    Assignee: Denso Corporation
    Inventors: Masanori Ohmi, Tsutomu Shiga, Masami Niimi, Tadahiro Kurasawa
  • Magnet switch for starter
    Patent number: 6822544
    Abstract: In a magnet switch for a starter, a first contact portion and a second contact portion are connected in parallel between a battery and a motor. The first contact portion makes contact through a resistive component so that the motor starts rotation at low speed. By this, a pinion is pushed in an axial direction by an axial component of splines and brought into mesh with a ring gear in a condition that its rotation is restricted. Thereafter, the second contact portion makes contact in accordance with further movement of a plunger so that electric power is fully supplied to the motor through the second contact portion, thereby starting engine. A fixed contact of the first contact portion is made of a carbon material. The resistive component is provided by the carbon material.
    Type: Grant
    Filed: April 1, 2003
    Date of Patent: November 23, 2004
    Assignee: Denso Corporation
    Inventors: Tsutomu Shiga, Masami Niimi
  • Rotary electric machine having laminated armature core
    Publication number: 20040222714
    Abstract: An armature composed of a shaft and an armature core is rotatably supported in a housing of a rotary electric machine. The shaft is forcibly inserted into a center hole of the armature core formed by laminating core sheets. Each core sheet has a center hole and outer holes connected to the center hole. A contour of the center hole is not continuous because the outer holes are connected thereto. The shaft can be firmly connected to the laminated core sheets with a relatively low inserting force. The shaft has a smooth outer surface having no knurls or the like. In addition, the outer holes of the laminated core sheets form cooling air passages in the armature core in its axial direction.
    Type: Application
    Filed: March 26, 2004
    Publication date: November 11, 2004
    Applicant: DENSO CORPORATION
    Inventors: Shinji Usami, Masami Niimi, Tsutomu Shiga, Masanori Ohmi
  • Multilayer brush
    Patent number: 6815862
    Abstract: In a multilayer brush composed chiefly of copper and graphite and incorporated therein with a solid lubricant, which consists essentially of two types of brushes, a high-copper-content part brush containing the copper in a large quantity and a low-copper-content part brush containing the copper in a small quantity, at least the high-copper-content part brush contains zinc in an amount of from 0.1% by weight to 5% by weight, and the zinc and the copper form an alloy. This can provide a multilayer brush having a superior durability, which can prevent the performance of motors from lowering, without use of the harmful substance such as lead, and may less undergo any wear due to mechanical and electrical sparkling of the brush.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: November 9, 2004
    Assignee: Denso Corporation
    Inventors: Kyoji Inukai, Youichi Murakami, Yasuyuki Wakahara, Masami Niimi, Teruo Kobayashi, Hiroaki Kawamura, Nobuyuki Yamashita
  • Starter having pinion-rotation-restricting mechanism for use in automotive vehicle
    Publication number: 20040211273
    Abstract: A starter for cranking an internal combustion engine is composed of an electric motor, an output shaft driven by the electric motor, a pinion gear unit helical-spline-coupled to the output shaft, and a magnetic switch for supplying electric power to the electric motor in an ON-and-OFF fashion and for engaging or disengaging the pinion gear unit with a ring gear of the engine. The pinion gear unit is made by fixedly connecting a pinion gear, a rotation-restricting ring and a bearing member together. These components are separately formed from one another and then assembled to a unitary body of the pinion gear unit. Therefore, they can be forged with simple dies, or may be manufactured by other methods such as machining.
    Type: Application
    Filed: April 15, 2004
    Publication date: October 28, 2004
    Applicant: DENSO CORPORATION
    Inventors: Kazushige Okumoto, Masami Niimi, Tsutomu Shiga
  • Starter for an internal combustion engine
    Publication number: 20040207204
    Abstract: A starter for an internal combustion engine has a resistance ratio rM/rB equal to or less than 0.4, when rM represents a motor internal resistance and rB represents a battery internal resistance. Furthermore, the starter has a size ratio L/D equal to or less than 1.0, when L represents an axial length of the armature and D represents an outer diameter of the armature. Furthermore, a means for suppressing temperature rise is provided for the starter.
    Type: Application
    Filed: April 13, 2004
    Publication date: October 21, 2004
    Applicant: DENSO CORPORATION
    Inventors: Tsutomu Shiga, Masami Niimi, Masanori Ohmi
  • Method of manufacturing yoke of rotary electric machine
    Patent number: 6804874
    Abstract: A method of manufacturing a yoke includes a step of cutting a steel plate into a rectangular sheet having a plurality of first dovetail convexities at one end thereof and a plurality of second dovetail convexities at the other end, a step of rolling the rectangular sheet into a cylinder to fit the first dove tails and the second dove tails to each other and a step of punching border portions of the first dove tails and the second dove tails. The second dovetail convexities are formed to be the same in shape as the first dovetail convexities so that they can fit to the first dovetail convexities. A smooth-faced yoke can be manufacture without using an expensive welder.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: October 19, 2004
    Assignee: Denso Corporation
    Inventors: Masami Niimi, Hideki Ichikawa, Masahiro Takada, Akifumi Hosoya, Masahiro Katoh
  • Commutator integrated armature of electric rotary machine
    Patent number: 6806613
    Abstract: A commutator-integrated armature of a rotary electric machine is comprised of a rotary shaft, an armature core composed of a plurality of laminated sheets, an armature coil composed of a plurality of conductor segments. The conductor segments have in-slot portions respectively inserted into a plurality of slots of the armature core and end portions forming a flat commutator. The armature core has an anchoring portion for anchoring a part of each of the in-slot portions to the armature core more strongly than the rest thereof. The surface of the flat commutator is maintained flat even if the conductor segments repeat thermal expansion and contraction.
    Type: Grant
    Filed: March 13, 2001
    Date of Patent: October 19, 2004
    Assignee: Denso Corporation
    Inventors: Jiro Ebihara, Kenichi Shibayama, Masami Niimi, Osamu Ina
  • Rotor of rotary electric machine and method of manufacturing the rotor
    Publication number: 20040201304
    Abstract: In a rotor of a rotary electric machine, a rotor core is formed by helically winding a material sheet. The material sheet forms teeth on a first side of a middle connecting portion and projections projecting from a second side of the connecting portion in a direction opposite to the teeth. The material sheet is one of a pair of material sheets formed in a single base sheet in a form of belt. In the base sheet, the material sheets are arranged such that the projections are intermeshed with each other. The material sheet is helically wound such that the projections are located at an inner diameter side of the rotor core.
    Type: Application
    Filed: March 30, 2004
    Publication date: October 14, 2004
    Applicant: DENSO CORPORATION
    Inventors: Masami Niimi, Tsutomu Shiga, Masanori Ohmi
  • Electromagnetic switch and starter using the same
    Publication number: 20040178870
    Abstract: An electromagnetic switch includes a contact holding member connected to a plunger in order to hold a first movable contact. The contact holding member is disposed outside a switch case covering a periphery of an excitation coil. A return spring pushes the plunger back in the opposite direction to a fixed iron core through the contact holding member when electric power supply to the excitation coil is stopped. The return spring is disposed outside the switch case. In this structure, a spring holding portion does not need to be disposed in the fixed iron core and the plunger. Therefore, an area where the fixed iron core attracts the plunger can be increased, so that an attraction force can be increased.
    Type: Application
    Filed: March 9, 2004
    Publication date: September 16, 2004
    Applicant: DENSO CORPORATION
    Inventors: Masanori Ohmi, Tsutomu Shiga, Masami Niimi, Tadahiro Kurasawa
  • MULTILAYER BRUSH
    Publication number: 20040174088
    Abstract: In a multilayer brush composed chiefly of copper and graphite and incorporated therein with a solid lubricant, which consists essentially of two types of brushes, a high-copper-content part brush containing the copper in a large quantity and a low-copper-content part brush containing the copper in a small quantity, at least the high-copper-content part brush contains zinc in an amount of from 0.1% by weight to 5% by weight, and the zinc and the copper form an alloy. This can provide a multilayer brush having a superior durability, which can prevent the performance of motors from lowering, without use of the harmful substance such as lead, and may less undergo any wear due to mechanical and electrical sparkling of the brush.
    Type: Application
    Filed: February 4, 2004
    Publication date: September 9, 2004
    Inventors: Kyoji Inukai, Youichi Murakami, Yasuyuki Wakahara, Masami Niimi, Teruo Kobayashi, Hiroaki Kawamura, Nobuyuki Yamashita
  • Wire connecting structure of electromagnetic switch of starter
    Publication number: 20040159534
    Abstract: In a starter, an electromagnetic switch is mounted to a seating. A lead wire of an exciting coil is led to an outside of a switch case by a coil-leading portion and is connected to a male terminal, which is fixed to the coil-leading portion by welding. The coil-leading portion is integrally provided with an end plate portion of a bobbin around which the exciting coil is wound. The coil-leading portion passes through and projects from a bottom surface of the switch case to the outside. A metal member, in a form of a plate, is insert-molded in the seating. A 50 terminal is provided on an end of the metal member and a female terminal is provided on an opposite end of the metal member. When the electromagnetic switch is mounted to a predetermined position of the seating, the female terminal engages with the male terminal.
    Type: Application
    Filed: January 14, 2004
    Publication date: August 19, 2004
    Applicant: DENSO CORPORATION
    Inventors: Tadahiro Kurasawa, Tsutomu Shiga, Masami Niimi
  • Armature of rotary electric machine and starter having the armature
    Publication number: 20040140729
    Abstract: In an armature for a rotary electric machine, segments of a commutator are provided by coil ends arranged on one axial end of the armature. A brush of the rotary electric machine is arranged to contact the commutator segments in an axial direction of the armature. On the surfaces of the commutator segments, a plurality of grooves is formed in circular rows concentric with an armature shaft, at approximately equal intervals in a radial direction. The contact area of the commutator and the brush is increased because of the grooves, in comparison to that of an armature having flat commutator surfaces. Therefore, because current density on the contact surface during the energization is approximately between 50% to 60%, voltage drop loss is reduced accordingly. As a result, power output is improved.
    Type: Application
    Filed: January 12, 2004
    Publication date: July 22, 2004
    Applicant: DENSO CORPORATION
    Inventor: Masami Niimi
  • Starter for cranking internal combustion engine having main and auxiliary switches
    Patent number: 6759756
    Abstract: A starter includes an electric motor, a pinion gear driven by the electric motor and a magnetic switch having a plunger driven by a magnetic coil. Electric power to be fed to both the electric motor and the magnetic coil is supplied from an on-board battery through a single common input terminal of the starter. The magnetic switch is composed of a main switch through which a full power is supplied to the electric motor and an auxiliary switch through which a limited power is supplied. Upon closing the auxiliary switch, the motor is driven at a low speed and the pinion gear is engaged with a ring gear of the engine. Then, the main switch is closed to thereby crank up the engine with a full power.
    Type: Grant
    Filed: June 12, 2003
    Date of Patent: July 6, 2004
    Assignee: Denso Corporation
    Inventors: Tsutomu Shiga, Masami Niimi
  • Metal-graphite brush and production method thereof
    Patent number: 6758881
    Abstract: Ag particles produced by chemical reduction and having a mean particle size of 5 &mgr;m are added by 0.05-3 wt % and Zn are added by 2-10 wt % to a Pb-less brush body containing graphite, Cu and a metal sulfide solid lubricant of a metal-graphite brush.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: July 6, 2004
    Assignees: Tris Inc., Denso Corporation
    Inventors: Takayoshi Otani, Osamu Takada, Mitsuo Ikeda, Yoichi Sakaura, Naoki Morita, Takahiro Sakamoto, Kyoji Inukai, Youichi Murakami, Yasuyuki Wakahara, Masami Niimi, Ryochi Honbo
  • Starter and magnet switch thereof
    Publication number: 20040113728
    Abstract: A magnet switch for a starter includes a exciting coil member, a switch case, a stator core, a plunger disposed in a hollow portion of the exciting coil to confront the stator core through an air gap, a link member connected to the plunger and disposed outside the switch case, a movable contact supported and insulated by the link member to move together with the plunger; and a stationary contact disposed opposite the movable contact. The link member has a pair of arms which axially extend along outer surfaces of the switch case. The switch case, the exciting coil and the plunger respectively have elliptic cross sections. The pair of arms is disposed to extend along the minor axis of the elliptic cross section to be movable in the axial direction of the switch case along the outer surface thereof.
    Type: Application
    Filed: November 26, 2003
    Publication date: June 17, 2004
    Applicant: DENSO CORPORATION
    Inventors: Masanori Ohmi, Tadahiro Kurasawa, Tsutomu Shiga, Masami Niimi
  • Starter having pinion-rotation-restricting member for use in automotive vehicle
    Publication number: 20040107932
    Abstract: A pinion gear of a starter is engaged with a ring gear of an internal combustion engine by restricting rotation of the pinion gear while driving a motor at a low speed. After the engagement is established, the motor is driven at a full speed by supplying a full current, thereby cranking up the engine. A crank bar for transferring movement of a plunger in a magnetic switch to a pinion-rotation-restricting member is divided into two or three portions. After the divided portions are assembled to the starter, they are connected together to form a solid piece. In this manner, a process of assembling the crank bar into the starter is simplified.
    Type: Application
    Filed: November 24, 2003
    Publication date: June 10, 2004
    Applicant: DENSO CORPORATION
    Inventors: Mitsuhiro Murata, Masami Niimi, Tsutomu Shiga, Masanori Ohmi
  • Starter having pinion-rotation-restricting member for use in automotive vehicle
    Publication number: 20040108727
    Abstract: A pinion gear of a starter is engaged with a ring gear of an internal combustion engine by restricting rotation of the pinion gear while driving a motor at a low speed. After the engagement is established, the motor is driven at a full speed by supplying a full current, thereby cranking up the engine. After the engine is cranked up, the engagement between the pinion gear and the ring gear is released. In order to prevent the motor from being driven at the full speed before the pinion gear fully engages with the ring gear, rigidity of a crank bar for restricting the pinion rotation is made sufficiently high to generate a spring-load that exceeds a force for driving a plunger that closes a switch for supplying the full current.
    Type: Application
    Filed: November 6, 2003
    Publication date: June 10, 2004
    Applicant: DENSO CORPORATION
    Inventors: Tadahiro Kurasawa, Tsutomu Shiga, Masami Niimi
  • Rotor of rotary electric machine having commutator surface facing axial rear end
    Publication number: 20040108786
    Abstract: A rotor of a rotary electric machine such as a starter motor for cranking an internal combustion engine is substantially composed of an armature core fixed to a rotating shaft and an armature coil disposed in slots of the armature core. The armature coil is constituted by electrically connecting conductor segments. A rear end portion of each conductor segment disposed in the radial outside of the slot is bent and arranged on an axial rear surface of the armature core, thereby forming a commutator surface. The thickness of the rear end portion in the axial direction gradually increases from its radial outside toward its radial inside, and the cross-sectional area of the rear end portion is made uniform throughout its entire length.
    Type: Application
    Filed: November 14, 2003
    Publication date: June 10, 2004
    Applicant: DENSO CORPORATION
    Inventors: Masami Niimi, Tsutomu Shiga