Abstract: With regard to a surface hardening method wherein a surface of an engine member is coated with an alloy layer having high abrasive resistance so as to improve the life of the member and a production method of a piston or the like wherein abrasive resistance of the member is improved by the hardening method, a surface of a metal base material is coated uniformly with a mixture including metal powder, a binder and a solvent so as to form a coat, and the coat is dried and applied thereon with a laser or electron beam so as to be sintered and dispersed for forming an alloy layer on a surface of the metal base material and for bonding the alloy layer to the metal base material.

Abstract: With regard to a surface hardening method that a surface of an engine member is coated with an alloy layer having high abrasive resistance so as to improve life of the member and a production method of a piston or the like that abrasive resistance of the member is improved by the hardening method, a surface of a metal base material is coated uniformly with mixture including metal powder, a binder and solvent so as to form a coat, and the coat is dried and applied thereon with laser or electron beam so as to be sintered and dispersed for forming an alloy layer on a surface of the metal base material and for bonding the alloy layer to the metal base material.

Abstract: In molding coils wound around a motor rotor with resin material in a die assembly, the coil ends projecting from either axial end of the motor core are compressed radially inward by small diameter portions formed in the die surface. Because the unnecessary deposition of the resin material over the coil ends is minimized, the material cost can be reduced. Also, the elimination or the reduction of the need to eliminate excess resin material from the coil ends simplifies the production process, and reduces the production cost. Additionally, the reduction in the mass of the resin material over the coil ends, as well as the constraining of the coil wire into a relatively radially inner parts reduces the moment of inertia of the motor rotor, and can thereby improve the performance of the motor.

Abstract: In molding coils wound around a motor rotor with resin material in a die assembly, the coil ends projecting from either axial end of the motor core are compressed radially inward by small diameter portions formed in the die surface. Because the unnecessary deposition of the resin material over the coil ends is minimized, the material cost can be reduced. Also, the elimination or the reduction of the need to eliminate excess resin material from the coil ends simplifies the production process, and reduces the production cost. Additionally, the reduction in the mass of the resin material over the coil ends, as well as the constraining of the coil wire into a relatively radially inner parts reduces the moment of inertia of the motor rotor, and can thereby improve the performance of the motor.

Abstract: A grinding swarf collector is disclosed. An outer periphery and side surfaces of a grinding wheel, except a site of grinding including a grinding point, are covered with a cover. A dust collecting plate is disposed behind the grinding point in a direction of rotation of the grinding wheel. Swarf scattered rearward collides with the dust collecting plate, and is scooped up thereby toward a suction port. The suction port sucks the swarf, which is sucked into a vacuum cleaner. Swarf scattered around the grinding wheel collides with the cover, falls to an opening formed below, and is sucked through the suction port. Thus, grinding swarf is collected efficiently.

Abstract: A piezoelectric element comprises a metallic plate-shaped diaphragm, a plate-shaped piezoelectric body, and electrodes provided on both surfaces of the piezoelectric body, wherein one electrode is fixed to a main surface of the diaphragm. An extension electrode is extended onto a projection projecting from the diaphragm while it is insulated from the diaphragm. The extension electrode is extended from the diaphragm to the projection while it is insulated from the diaphragm. The extension electrode is electrically connected to the electrode which is not fixed to the diaphragm of the piezoelectric body. The piezoelectric element is attached to a case while allowing a main surface of the projection on which the extension electrode is provided to be directed outward.

Abstract: A piezoelectric acoustic device comprises a piezoelectric element composed of a metallic plate-shaped diaphragm, a plate-shaped piezoelectric body, electrodes provided on both main surfaces of the piezoelectric body, one electrode being fixed and electrically connected to a main surface of the diaphragm, and a casing for accommodating the piezoelectric element therein and forming a resonant chamber together with the piezoelectric body. The piezoelectric element further comprises a projection projecting from the diaphragm and an extension electrode, the extension electrode being extended onto the projection while being insulated from the diaphragm, the extension electrode being electrically connected to another electrode which is not fixed to the diaphragm of the piezoelectric body, the piezoelectric element being attached to the casing while allowing a main surface of the projection attaching the extension electrode thereto to direct outward.

Abstract: A piezoelectric acoustic device comprises a case and a piezoelectric element which is accommodated in the case and has an inner peripheral surface thereof supported by an inner peripheral surface of the case at a middle portion thereof. A plurality of projections are provided on an inner peripheral surface of the case and spaced circumferentially along the inner peripheral surface of the case for supporting the peripheral portion of the piezoelectric element. A gap between the peripheral portion of the piezoelectric element and the inner peripheral surface of the case is closed by an elastic adhesive. A plurality of projections provided on and spaced circumferentially along the inner peripheral surface of the case contact the periphery of the piezoelectric element at the tips thereof, which restricts a radial movement of the piezoelectric element relative to the case.

Abstract: In a method for forming the coils passed through the core slots of a motor rotor so as to keep the coils fully received in the core slots, a motor rotor, in which coils are wound around the core thereof, is received in a metallic mold die which has a die surface spaced from the outer circumferential surface of the core by a certain gap, and resin material is injected from an injection inlet provided in an axial end of the upper metallic mold die. As the resin material is injected into the cavity of the metallic mold die, the resin material first fills the gap, and then flows into the core slots from the outer periphery thereof. The flow and the pressure of the resin material causes the coils to be pushed toward the bottom regions of the core slots, and once the filled resin material is cured, the coils are firmly secured well inside the core slots.