Kuroda Precision Industries Ltd.

Masanobu Ikeda

Tomoaki Murayama

Osamu Fukuyama

Tetsuya Nishizawa

Kazuo Nakamura

In manufacturing a magnet embedded core, creation of flash, and problems associated with flash are prevented. A device for manufacturing the magnet embedded core comprises a base () comprising an upper surface at which a resin pot chamber () for storing molten resin opens, a separator plate () detachably placed on the upper surface of the base () to support a rotor core () thereon and having a gate () and a cull opening () communicating the magnet insertion hole () of the rotor core () with the resin pot chamber (), and a plunger () movably provided in the resin pot chamber () to press the molten resin in the resin pot chamber () into the magnet insertion hole () via the gate () and the cull opening (), wherein an annular recess () is formed on the upper surface of the base () so as to extend outward of the resin pot chamber () and communicate with the resin pot chamber ().

Device and method for manufacturing magnet embedded core

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 () for a rotor core () including a magnet insertion hole () forming a through hole defining openings on end surfaces in an axial direction includes: a first plate () configured to contact against one of the end surfaces of the rotor core () and including a gate () configured to communicate with the corresponding opening of the magnet insertion hole (); a second plate () configured to oppose another of the end surfaces of the rotor core (); a closure member () coupled to the second plate () via a compression spring member () and configured to be capable of closing the opening of the magnet insertion hole () on the other of the end surfaces; and a coupling member () that couples the first plate () and the second plate () to each other such that the closure member () closes the opening and a spring force of the compression spring member () becomes a prescribed value.

Rotor core retaining jig, manufacturing device and manufacturing method for magnet embedded core

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 (), the inner peripheral surface of the gate (), the outer peripheral surface of the plunger (), and the like of the manufacturing device () for the magnet embedded core are constituted by chromium nitride layers () or the like.

Manufacturing device for magnet embedded core

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 () on which the rotor core retaining jig () is to be placed; an opposing base () joined to the support baseto oppose the support base (); a pressurizing device () provided on the opposing base () and configured to pressurize an upper plate () of the rotor core retaining jig () on the support base () toward a lower plate (); chuck devices () provided on the support base () to releasably grip the coupling rods () and capable of moving between a separated position where the coupling rods () are separated from engagement grooves () and an engaged position where the coupling rods () engage the engagement grooves (); and a fluid pressure cylinder device () provided on the support base () to drive each chuck device () between the separated position and the engaged position.

Setting device for rotor core retaining jig

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 () and an upper plate () configured to contact against the end surfaces of a rotor core () are provided with pin members () configured to enter a magnet insertion hole () to allow movement of a magnet () in a first direction, which is a separation direction of two mutually opposing inner surfaces (C,D) of a magnet insertion hole (), 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 (), in a state where the magnet insertion hole is not filled with resin.

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.

Growing community of inventors

Nagano, Japan

Masanobu Ikeda