摘要:
A loudspeaker includes the following components: a frame (5) that has a magnetic circuit (4) including a magnetic gap (4a) therein; and a diaphragm (6) that is bonded to a voice coil (7) fitted into the magnetic gap (4a) in the center thereof, and to the periphery of the frame (5) along the outer periphery thereof. The magnetic circuit (4) includes a yoke (1), a magnet (2), and a top plate (3). Tongue-shaped flanges (1a) are disposed at a substantially equidistant spacing in three positions to protrude from the top end face of the yoke (1). The total area of these tongue-shaped flanges (1a) in the three positions does not exceed a half of the total area corresponding to the flange part without flanges (1a). The frame (5) also includes engaging parts (5a) each for receiving one of the tongue-shaped flanges (1a) therein.
摘要:
A rotor yoke includes a substantially flat or annular flat cover portion coaxial or substantially coaxial with a rotational axis and a substantially cylindrical side wall portion extending from an outer circumference of the cover portion in a parallel or substantially parallel relationship with the rotational axis. The rotor yoke further includes a substantially annular flange portion extending radially outwards from an open end of the side wall portion. The cover portion and the side wall portion define a cup portion whose center of gravity deviates from the rotational axis in a plane perpendicular or substantially perpendicular to the rotational axis, and the flange portion has an outer circumferential circle whose center deviates from the rotational axis in a direction opposite to the deviation direction of the center of gravity of the cup portion.
摘要:
The present invention provides a loudspeaker including an edge formed in such manner that a thickness of a sectional shape in a radial direction increases from an inner peripheral portion toward an outer peripheral portion. Due to this structure, a mechanical impedance of the edge against a diaphragm is decreased and bad influences on a vibration mode of the diaphragm are suppressed, and also, vibration energy is absorbed by a thick portion of the outer peripheral portion, thereby suppressing standing waves of the diaphragm.
摘要:
The manufacturing method of a rotor holder according to the present invention includes a step in which a top plate portion having a substantially discoid shape substantially centered about a central axis, and a side wall portion extending from an outer circumferential edge of the top plate portion are formed simultaneously by feeding a metal plate in a predetermined direction and pressing the metal plate by a die. Also, the present manufacturing method includes a step in which a punched portion is formed at the side wall portion.
摘要:
The present invention provides a loudspeaker which is excellent in acoustic characteristics such as frequency characteristics and distortion characteristics. Particularly, edge 1 is formed in such manner that a thickness of sectional shape in radial direction increases from inner periphery portion 12 toward outer periphery portion 13. Due to this structure, a mechanical impedance of edge 1 against diaphragm 2 is decreased and bad influences on a vibration mode of the diaphragm are suppressed, and also, vibration energy is absorbed by the thick portion of the outer periphery portion, thereby suppressing standing waves of the diaphragm. The structure increases an efficiency of the medium and high frequency range sounds radiated from the loudspeaker, and further, greatly contributes to improve frequency characteristics, nonlinear distortion characteristics, and transient characteristics.
摘要:
A speaker edge is made of a thermosetting composition consisting of a polyurethane prepolymer and an inactivated solid polyamine as a latent hardener. A gas is dispersed in the thermosetting composition, prior to feed into a mold, so that it can foam and solidify to give the speaker edge. In a method of making the speaker edge, the composition will be injected into a female mold segment heated below the critical thermosetting temperature, foaming the composition. Then placed in the female segment is a male segment heated above the critical temperature, causing the ingredients to react with each other to solidify in the mold. An apparatus for making the speaker edge from the composition has: a device for intake of a gas, another device for injecting the composition into the gas, another device for mechanically dispersing the gas throughout the composition, still another device for injection of this gas-containing composition into a female mold segment, a further device for placing a male segment in the female segment, and a still further device for solidifying the composition, while foaming it.
摘要:
Provided are alloy flakes for rare earth sintered magnet, which achieve a high rare earth component yield after pulverization with respect to before pulverization and a uniform particle size after pulverization, and a method for producing such alloy at high energy efficiency in an industrial scale. The method includes (A) preparing an alloy melt containing R composed of at least one element selected from rare earth metal elements including Y, B, and the balance M composed of Fe, or of Fe and at least one element selected from transition metal elements other than Fe, Si, and C, (B) rapidly cooling/solidifying the alloy melt to not lower than 700° C. and not higher than 1000° C. by strip casting with a cooling roll, and (C) heating and maintaining, in a particular temperature range, alloy flakes separated from the roll by rapid cooling and solidifying in step (B) before the flakes are cooled to not higher than 500° C., to obtain alloy flakes having a composition of 27.0 to 33.0 mass % R, 0.90 to 1.30 mass % boron, and the balance M.
摘要:
Provided are raw material alloy flakes for a rare earth sintered magnet and a method for producing the same. The alloy flakes have a roll-cooled face, and (1) contain at least one R selected from rare earth metal elements including Y, B, and the balance M including iron, at a particular ratio; (2) as observed in a micrograph at a magnification of 100× of its roll-cooled face, have not less than 5 crystals each of which is a dendrite grown radially from a point of crystal nucleation, and crosses a line segment corresponding to 880 μm; and (3) as observed in a micrograph at a magnification of 200× of its section taken generally perpendicularly to its roll-cooled face, have an average distance between R-rich phases of not less than 1 μm and less than 10 μm.
摘要:
A turntable for a storage disk drive apparatus includes a plate member made of a ferromagnetic material and a central resin member arranged at the center of the plate member and formed into a single member by injection-molding a resin. The plate member includes a peripheral plate portion and a central plate portion positioned higher than the peripheral plate portion. The central plate portion includes a plate center hole defined at the center of the plate member. The central resin member includes a resinous cylinder portion extending through the plate center hole and defining a resin central through-hole, a disk guide portion arranged to guide a disk center hole, and a resinous connector portion arranged above the central plate portion to interconnect the resinous cylinder portion and the disk guide portion.
摘要:
A turntable for a storage disk drive apparatus includes a plate member made of a ferromagnetic material and a central resin member arranged at the center of the plate member and provided with an outer peripheral portion positioned above the plate member. The central resin member includes claws extending downwards from the outer peripheral portion and claw position holes overlapping with the claws in the direction parallel to the center axis of the central resin member. The claw position holes include inner surfaces spaced apart from an edge of the plate member. The inner surfaces are defined by the resin. The central resin member includes a resin layer extending in the direction perpendicular to the center axis. The resin layer exists between the portion of the edge of the plate member around the claw position holes and the claw position holes.