Patents Assigned to Kuroda Precision Industries Ltd.
  • Patent number: 11552540
    Abstract: In a method of manufacturing a magnet embedded core (1), creation of unnecessary resin from the resin for fixedly securing the magnet is prevented. The method includes a resin charging step of charging resin material (33) in solid form into the magnet insertion hole; a melting step of melting the resin material (33) in the magnet insertion hole, and a pressurization step of pressurizing an interior of the magnet insertion hole (3). The melting step includes melting the resin material (33) at least partly by preheating and inserting the magnet (4) into the magnet insertion hole (3).
    Type: Grant
    Filed: April 13, 2016
    Date of Patent: January 10, 2023
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventor: Osamu Fukuyama
  • Patent number: 11532973
    Abstract: To prevent the axial compressive force that acts on the rotor core from becoming unnecessarily large and to enable a high-quality magnet embedded core to be manufactured efficiently, a retaining jig (10) for a rotor core (2) including a magnet insertion hole (4) forming a through hole defining openings on end surfaces in an axial direction includes: a first plate (12) configured to contact against one of the end surfaces of the rotor core (2) and including a gate (20) configured to communicate with the corresponding opening of the magnet insertion hole (4); a second plate (14) configured to oppose another of the end surfaces of the rotor core (2); a closure member (26) coupled to the second plate (14) via a compression spring member (28) and configured to be capable of closing the opening of the magnet insertion hole (4) on the other of the end surfaces; and a coupling member (30) that couples the first plate (12) and the second plate (14) to each other such that the closure member (26) closes the opening and
    Type: Grant
    Filed: October 11, 2018
    Date of Patent: December 20, 2022
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Masanobu Ikeda, Osamu Fukuyama, Tomoaki Murayama
  • Patent number: 11355282
    Abstract: A manufacturing method for a laminated iron core includes conveying a sheet steel strip in an intermittent manner in a lift up state, with upward movement of the strip being limited by a guiding member provided on a lower holder; punching an outer shape of each iron core laminae; and applying adhesive agent to a surface of the strip before the punching. The adhesive agent is applied in a state in which a pilot pin is inserted in a pilot hole of the strip and when the strip is about to be pressed against or is being pressed against the die plate by a stripper provided on an upper holder. After application of the adhesive agent, the strip is returned to the lift up state by raising the upper holder, with a lifter and the stripper plate being in abutment with the lower and upper surfaces of the strip, respectively.
    Type: Grant
    Filed: January 9, 2017
    Date of Patent: June 7, 2022
    Assignee: Kuroda Precision Industries Ltd.
    Inventors: Hironobu Okudaira, Hideo Horii, Kenichi Shindo
  • Patent number: 11356003
    Abstract: To improve the abrasion resistance and releasability of the inner peripheral surfaces of a resin pot chamber, a gate, and the like in a manufacturing device for a magnet embedded core without using cemented carbide, the inner peripheral surface of the resin pot chamber (64), the inner peripheral surface of the gate (50), the outer peripheral surface of the plunger (62), and the like of the manufacturing device (10) for the magnet embedded core are constituted by chromium nitride layers (59, 65, 47) or the like.
    Type: Grant
    Filed: November 7, 2018
    Date of Patent: June 7, 2022
    Assignee: Kuroda Precision Industries Ltd.
    Inventors: Masanobu Ikeda, Tomoaki Murayama
  • Patent number: 11264872
    Abstract: To automate setting of coupling rods when using a rotor core retaining jig and thereby to improve the production efficiency of a magnet embedded core, a setting device includes: a support base (42) on which the rotor core retaining jig (10) is to be placed; an opposing base (46) joined to the support base 42 to oppose the support base (42); a pressurizing device (48) provided on the opposing base (46) and configured to pressurize an upper plate (14) of the rotor core retaining jig (10) on the support base (42) toward a lower plate (12); chuck devices (126) provided on the support base (42) to releasably grip the coupling rods (30) and capable of moving between a separated position where the coupling rods (30) are separated from engagement grooves (32, 34) and an engaged position where the coupling rods (30) engage the engagement grooves (32, 34); and a fluid pressure cylinder device (120) provided on the support base (42) to drive each chuck device (126) between the separated position and the engaged position
    Type: Grant
    Filed: March 12, 2019
    Date of Patent: March 1, 2022
    Assignee: Kuroda Precision Industries Ltd.
    Inventors: Tomoaki Murayama, Osamu Fukuyama, Masanobu Ikeda
  • Patent number: 11258340
    Abstract: To allow necessary movement of a magnet in a magnet insertion hole during a manufacturing process so that a magnet embedded core in which the magnet is positioned as designed can be manufactured efficiently, a lower plate (12) and an upper plate (14) configured to contact against the end surfaces of a rotor core (2) are provided with pin members (37, 39) configured to enter a magnet insertion hole (4) to allow movement of a magnet (5) in a first direction, which is a separation direction of two mutually opposing inner surfaces (4C, 4D) of a magnet insertion hole (4), and to restrict movement of the magnet in a second direction orthogonal to the first direction as viewed in the axial direction of the magnet insertion hole (4), in a state where the magnet insertion hole is not filled with resin.
    Type: Grant
    Filed: March 22, 2019
    Date of Patent: February 22, 2022
    Assignee: Kuroda Precision Industries Ltd.
    Inventors: Masanobu Ikeda, Tomoaki Murayama, Osamu Fukuyama
  • Patent number: 11223261
    Abstract: A magnet embedded core is manufactured in a stable manner even when using a die clamping device having a large rated clamping force by preventing an excessive pressurizing force from being applied to a laminated iron core, performing the clamping with an appropriate pressurizing force so to minimize leakage of the resin out of magnet insertion holes, and suppressing a reduction in the geometric and dimensional precision of the laminated iron core. A die clamping device for driving a moveable platen in a direction toward and away from a fixed lower platen is configured to include a toggle link mechanism. In a fully extended state of the toggle link mechanism, an upper die abuts an end surface of the laminated iron core to close openings of the magnet insertion holes and pressurize the laminated iron core in a laminating direction.
    Type: Grant
    Filed: September 9, 2016
    Date of Patent: January 11, 2022
    Assignee: Kuroda Precision Industries Ltd.
    Inventors: Hironobu Okudaira, Tomoaki Murayama, Osamu Fukuyama
  • Patent number: 11201526
    Abstract: A magnet embedded core is manufactured in a stable manner by preventing an excessive pressurizing force from being applied to the laminated iron core and performing the clamping with an appropriate pressurizing force so that the leakage of the resin out of the magnet insertion holes can be minimized, and the reduction in the geometric and dimensional precision of the laminated iron core may be suppressed. An electric die clamping device is used, such that a laminated iron core is placed on one of a fixed die and a moveable die and upon clamping by the die clamping device, the other of the fixed die and the moveable die is caused to abut onto an end surface of the laminated iron core to close openings of magnet insertion holes and pressurize the laminated iron core in a laminating direction.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: December 14, 2021
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventor: Osamu Fukuyama
  • Patent number: 11201527
    Abstract: To prevent creation of unnecessary resin when fixing a magnet with resin, a manufacturing method for manufacturing a magnet embedded core comprises: a placing step of placing the rotor core on a mounting table such that an end surface of the rotor core is in contact with the mounting table; a resin charging step of charging the resin in solid state into the magnet insertion hole; a melting step of inciting the resin in the magnet insertion hole; a magnet inserting step of inserting the magnet into the magnet insertion hole; a closure step of closing the opening of the magnet insertion hole remote from the mounting table; and a resin pressurizing step of pressurizing the molten resin that has flowed into a buffer chamber formed in the mounting table from the opening of the magnet insertion hole on a side of the mounting table following the closure step.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: December 14, 2021
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Osamu Fukuyama, Tomoaki Murayama, Tetsuya Nishizawa, Masanobu Ikeda, Kazuo Nakamura
  • Patent number: 11174924
    Abstract: An end deflector includes a main portion including a ball delivery path that delivers balls between a rolling path and a ball return path, a tongue portion that guides the balls from the rolling path to the ball delivery path, and a pair of protruding pieces, that extend in the circumferential direction of each nut body from either side of the tongue portion with respect to the axial direction and define a ball guide groove that extends between the ball delivery path and the rolling path in cooperation with an inner circumferential surface of a deflector holding recess formed in a nut body, the main portion has an outer circumferential surface which opposes an inner circumferential surface of the deflector holding recess in the radial direction, a front-side portion of the outer circumferential surface with respect to a direction of insertion into the deflector holding recess is offset inward in the radial direction, and at least a rear-side portion of the outer circumferential surface with respect to the dir
    Type: Grant
    Filed: December 25, 2017
    Date of Patent: November 16, 2021
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Ryo Kaibe, Hitoshi Hakogi, Yoshimi Iwasaki, Tatsuto Omori
  • Patent number: 11065665
    Abstract: When provisionally blanking a lamination sheet by using a punch for provisional blanking and a counter punch, the displacement of pilot holes located around the lamination sheet is minimized. The progressive die machine (1) comprises a pilot hole punch (72), a punch (9) for provisionally punching an iron core laminate (2) from a strip (W) formed with pilot holes (P), a counter punch (31) provided in a lower die assembly (5) and configured to push the iron core laminate (2) against the punch (9), a stripper plate (13) for separating the strip (W) from the provisional blanking punch after a provisional punching, a punch (10) for completely separating the iron core laminate from the strip. At least a part of the stripper plate (13) associated with the provisionally blanking is not in contact with the strip, and at least a part of an outer peripheral part of the provisionally blanked lamination sheet is formed with a connecting portion (79) connected to the strip.
    Type: Grant
    Filed: December 17, 2015
    Date of Patent: July 20, 2021
    Assignee: KURODA PRECISION INDUSTRIES LTD
    Inventors: Hideo Horii, Kenichi Shindo, Shinichi Sakanishi
  • Patent number: 11038408
    Abstract: To prevent the creation of unnecessary resin from the resin used for fixing the magnet, a device for manufacturing a magnet embedded core including a magnet embedded in resin filling a magnet insertion hole (104) extending axially in a motor core comprises a resin charging device (80) configured to charge the resin (114) in solid form into the magnet insertion hole (104), a magnet insertion device (90) configured to insert the magnet (110) into the magnet insertion hole (104), and a heating device (70) configured to heat the motor core (101) to melt the resin (114) in solid form received in the magnet insertion hole (104).
    Type: Grant
    Filed: March 24, 2017
    Date of Patent: June 15, 2021
    Assignee: Kuroda Precision Industries Ltd.
    Inventor: Osamu Fukuyama
  • Patent number: 10873249
    Abstract: A resin filling method for a magnet embedded core includes: a fixing step of sandwiching the laminated iron core at axial ends thereof between a first mold and a second mold provided to face each other; and a resin injecting step of injecting a resin into the magnet insertion hole from a resin injecting portion provided in the first mold or the second mold, wherein in the resin injecting step, an end portion of the resin injecting portion is inserted into the magnet insertion hole beyond an axial end surface of the permanent magnet inserted in the magnet insertion hole.
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: December 22, 2020
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Hironobu Okudaira, Tomoaki Murayama, Osamu Fukuyama
  • Patent number: 10648546
    Abstract: To prevent the positional precision of the ball return passage and the tongue of the end deflector relative to the nut main body from being impaired by an axial force applied by a screw used for securing the end deflector to the nut main body, the end deflector includes a flange (32) provided at an axial end of a main part (30) of the end deflector and provided with an axial through hole (50) for receiving a screw which is threaded into the nut main body, and a rib (52) projecting from a radially inner edge of the flange to an inner side of the deflector receiving recess (26).
    Type: Grant
    Filed: December 6, 2018
    Date of Patent: May 12, 2020
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Ryo Kaibe, Hitoshi Hakogi, Yoshimi Iwasaki, Tatsuto Omori
  • Patent number: 10587172
    Abstract: A method of manufacturing a divided laminated iron core, wherein the iron core laminae includes first iron core laminae and second iron core laminae, includes: a first connecting-portion punching step of punching each of connecting portions between divided iron core pieces constituting each first iron core lamina in a sheet steel strip; a second connecting-portion punching step of punching each of connecting portions between divided iron core pieces constituting each second iron core lamina; and a stacking step of stacking at least one of the first iron core laminae and at least one of the second iron core laminae and joining together the stacked iron core laminae, wherein the connecting portions between the divided iron core pieces of each first iron core lamina are configured to be separated more easily than the connecting portions between the divided iron core pieces of each second iron core lamina.
    Type: Grant
    Filed: March 16, 2015
    Date of Patent: March 10, 2020
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Tomohiro Ogikubo, Tatsuhiro Yoshida, Noriyuki Hosokawa
  • Patent number: 10532501
    Abstract: A resin filling device includes: a first mold and a second mold provided so as to face each other to sandwich therebetween a laminated iron core and thereby to fix the laminated iron core; a flow path forming member provided to the first mold so as to be engageable with one of the axial ends of the laminated iron core and forming a resin flow path through which a resin flows; and a fitting member provided to the second mold to be fitted into an opening portion of the flow path forming member that is in communication with the resin flow path, wherein the fitting member is provided with a vent portion for discharging air in the resin flow path to outside.
    Type: Grant
    Filed: May 8, 2015
    Date of Patent: January 14, 2020
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Hironobu Okudaira, Tomoaki Murayama, Osamu Fukuyama
  • Patent number: 10413958
    Abstract: In a back pressure device for progressive die apparatus, a suitable back pressure can be produced during the blanking interval preventing the iron core laminates from being pushed upward by using a simple structure.
    Type: Grant
    Filed: March 4, 2014
    Date of Patent: September 17, 2019
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventors: Hideo Horii, Kenichi Shindo
  • Publication number: 20190259531
    Abstract: [Problem to be Solved] An adhesive agent is accurately applied on an adhesive agent applying surface. [Solution] Provided are guiding members (100) that guide the conveyance of a sheet steel strip (F) along an intermittent conveyance direction of the sheet steel strip (F) and limit the upward movement of the sheet steel strip (F), and an adhesive agent applying apparatus (50) that applies an adhesive agent to an adhesive agent applying surface at a section corresponding to an iron core lamina (A, W).
    Type: Application
    Filed: January 9, 2017
    Publication date: August 22, 2019
    Applicant: Kuroda Precision Industries Ltd.
    Inventors: Hironobu OKUDARIA, Hideo HORII, Kenichi SHINDO
  • Patent number: 10201844
    Abstract: In manufacturing a laminated iron core by laminating and bonding iron core laminates blanked from a sheet steel strip into a prescribed profile, the adhesive agent can be applied to the iron core laminates in a stable manner without regard to the arrangement and the number of the application spots on each iron core laminate. The metallic die machine (1) is provided with an adhesive agent application unit (12) configured to apply an adhesive agent to a prescribed area of the sheet steel strip (W) corresponding to the iron core laminates (2), and the adhesive agent application unit is provided with a casing (44) defining a plurality of adhesive agent storage chambers (55-57) for storing the adhesive agent before the adhesive agent is applied to the prescribed area. The casing is provided with a plurality of ejection orifices (H1 to H3) each communicating with a corresponding one of the adhesive agent storage chambers and configured to eject the adhesive agent.
    Type: Grant
    Filed: November 7, 2014
    Date of Patent: February 12, 2019
    Assignee: KURODA PRECISION INDUSTRIES LTD.
    Inventor: Koichi Nishinaka
  • Publication number: 20190028006
    Abstract: Provided is a method of manufacturing laminated steel plates by laminating a plurality of steel plates, the method including an application process of applying an adhesive agent on a surface of each of the steel plates, and a lamination process of laminating a steel plate, to which the adhesive agent is applied, and another steel plate while shifting positions of the steel plates about an axis with each other, and causing the steel plate to adhere to a laminated body using the adhesive agent, wherein, in the application process, the adhesive agent is applied such that the adhesive agent becomes in a shape that is continuous about a central axis when the steel plate and the other steel plate are adhered by the adhesive agent in the lamination process.
    Type: Application
    Filed: July 12, 2018
    Publication date: January 24, 2019
    Applicants: HONDA MOTOR CO., LTD., Kuroda Precision Industries Ltd.
    Inventors: Go Hamamura, Manabu Sakurada, Kenta Ninomiya, Koichi Nishinaka