Abstract: An optical pickup moves to the most inner circumference, then moves to outer circumference for a predetermined period and acquires address information there. Next, a difference XZ between the acquired address information and predetermined reference address information is calculated, and then difference YZ between address information which is acquired by performing above mentioned process in standard acceleration/deceleration control algorithm setting stage and the predetermined reference address information is calculated. Feed control amount is multiplied by a ratio between difference XZ and difference YZ.

Abstract: In an optical disk drive, in order to cancel a lens offset which may occur when performing a seek followed by read, a seek position must be set several sectors before a target position to read, resulting in a delay in access time.

Abstract: An optical disk device and a track hold control method thereof which can prevent runaway during tracking and carry out stable tracking even if the optical disk has a large eccentricity. An offset of a lens is monitored during track hold and kicking is effected at a timing at which the offset is the smallest when the lens passes over a track hold position, thus minimizing the offset upon tracking. Since there is no offset of the lens at the time of shifting to the tracking, a track hold processing is carried out stably.

Abstract: The invention offers an aluminum alloy that not only has high hardness accompanied by balanced ductility but also has high toughness and superior processability. The invention also offers a method for manufacturing an aluminum-alloy member that not only has high hardness accompanied by balanced ductility but also has high toughness and superior processability. The aluminum alloy comprises (1) not less than 0.1 wt. % and not more than 8 wt. % Constituent A comprising one or more kinds of elements selected from the group consisting of titanium, vanadium, hafnium, and zirconium, (2) not less than 0.1 wt. % and not more than 20 wt. % Constituent B comprising one or more kinds of elements selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, mischmetal, calcium, strontium, and barium, and (3) not less than 0.1 wt. % and not more than 20 wt. % Constituent C comprising one or more kinds of elements selected from the group consisting of magnesium and lithium.

Abstract: It is proposed to lessen the weight and improve the mechanical strength of a retainer of a valve open-close mechanism driven by an electromagnetic actuator used in an automotive internal combustion engine. The electromagnetic actuator is mounted in a housing mounted on an internal combustion engine body. A first stem has its tip abutting the valve, which is provided with a retainer and carries a first coil spring. A second stem is provided on the other side of an armature. The second stem has a retainer. Between this retainer and the housing, a second coil spring is mounted. At least one of these parts is made of a metal smaller in specific weight than iron or its alloy. Each retainer has a boss and an arcuate corner portion having a radius of curvature R of 1.0 mm or over between a spring abutting surface and the boss to relieve stress concentration.

Abstract: The invention offers an aluminum alloy that not only has high hardness accompanied by balanced ductility but also has high toughness and superior processability. The invention also offers a method for manufacturing an aluminum-alloy member that not only has high hardness accompanied by balanced ductility but also has high toughness and superior processability. The aluminum alloy comprises (1) not less than 0.1 wt. % and not more than 8 wt. % Constituent A comprising one or more kinds of elements selected from the group consisting of titanium, vanadium, hafnium, and zirconium, (2) not less than 0.1 wt. % and not more than 20 wt. % Constituent B comprising one or more kinds of elements selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, mischmetal, calcium, strontium, and barium, and (3) not less than 0.1 wt. % and not more than 20 wt. % Constituent C comprising one or more kinds of elements selected from the group consisting of magnesium and lithium.

Abstract: It is proposed to lessen the weight and improve the mechanical strength of a retainer of a valve open-close mechanism driven by an electromagnetic actuator used in an automotive internal combustion engine. The electromagnetic actuator is mounted in a housing mounted on an internal combustion engine body. A first stem has its tip abutting the valve, which is provided with a retainer and carries a first coil spring. A second stem is provided on the other side of an armature. The second stem has a retainer. Between this retainer and the housing, a second coil spring is mounted. At least one of these parts is made of a metal smaller in specific weight than iron or its alloy. Each retainer has a boss and an arcuate corner portion having a radius of curvature R of 1.0 mm or over between a spring abutting surface and the boss to relieve stress concentration.

Abstract: A tough and heat resisting aluminum alloy comprising aluminum, a transition metal element and a rare earth element, and having a modulated structure which comprises an aluminum matrix and an intermetallic compound precipitated to form a network in the aluminum matrix. Also disclosed in a process for producing the aluminum alloy which comprises the steps of: rapid quenching and solidifying a liquid aluminum alloy at a quenching rate of 102 to 105 K/sec to obtain an aluminum-based supersaturated solid solution; and heat treating the quenched aluminum-based supersaturated solid solution at a heat treating temperature of 473 K or higher, the temperature increasing rate to the heat treating temperature being 1.5 K/sec or higher.

Abstract: An aluminum alloy is industrially producible and has higher strength and toughness than the prior art alloys. The high-strength high-toughness aluminum alloy includes a first phase of .alpha.-aluminum consisting of crystal grains whose mean crystal grain size is within the range of 60 to 1000 nm and a second phase of at least two different of intermetallic compounds consisting of crystal grains whose mean crystal grain sizes are within the range of 20 to 2000 nm. The crystal grains of the intermetallic compounds are dispersed so that they are only intermittently, and not continuously, linked throughout the alloy material.

Abstract: A raw material for powder metallurgy contains at least 0.5 vol % and at most 10 vol % of alumina powder of which the sieve fraction with a sieve opening of 30 .mu.m is at most 0.1 wt %, and a remaining part of aluminum alloy powder. The moisture content of the alumina powder is at most 0.15 wt. % with respect to the alumina powder. Agglomeration of particles is thereby minimized or avoided. Highly reliable raw material for powder metallurgy having superior fatigue strength, impact resistance and wear resistance can be obtained. A method of preparing such a mixed powder raw material involves air classifying the powder materials, dry ball mixing the materials, and then annealing the mixed powder.

Abstract: An aluminum alloy structural member is crystalline. In producing this aluminum alloy structural member, a procedure is employed which includes forming a green compact by use of aluminum alloy having an amorphous phase, and subjecting the green compact to a powder forging technique. An aluminum alloy powder exhibiting an exotherm E smaller than 20 J/g at the time of the crystallization of the amorphous phases is used. By setting the exotherm E in such a range, cracking of the green compact due to a degassing can be avoided, even if the green compact is rapidly heated in a temperature-rising or heating course.

Abstract: A connecting rod as a shaft clamping member includes a rod member and cap, each of which has mating faces at circumferentially opposite ends of a semi-circular recess and which are fastened to each other by bolts by matching the opposed mating faces to each other to define a crank pin hole by the two semi-circular recesses. The rod member and the cap are forgings formed from an aluminum alloy and simultaneously produced by forging powder preforms of the rod member and cap in a cavity having the desired shape of the connecting rod. After forging, the opposed mating faces have an infinite number of recesses and projections which are formed from the flow of the material during the forging and which are in a matched and fitted relation to each other. Thus, any misalignment between and in a direction parallel to the mating faces can be prevented to avoid the generation of a situation that only the rod member receives a stress. This achieves a prolongation in the life of the connecting rod of the aluminum alloy.

Abstract: In a powder forging process, a heated green compact is placed in a stationary die and subjected to a press-forging carried out mainly to reduce the thickness thereof by cooperation of the stationary die with a movable die. The press-forging is performed at two pressing steps. After placement of the green compact into the concave molding portion of the stationary die, the pressing step were carried out. Thus, it is possible to produce a forged product having a high strength and a high toughness. A heated heat insulator also may be placed in the stationary die to provide a temperature-retaining effect to the green compact before and during pressing.

Abstract: A dispersion-strengthened aluminum alloy having a composite structure containing a matrix of .alpha.-aluminum and a precipitation deposited phase of an intermetallic compound with the intermetallic compound in a volume ratio of not more than 35 vol. %, has both high strength and high toughness. The precipitation phase of the intermetallic compound has an aspect ratio of not more than 3.0, the .alpha.-aluminum has a crystal grain size which is at least twice the grain size of the precipitation phase of the intermetallic compound, and the crystal grain size of the .alpha.-aluminum is not more than 200 nm. It is possible to obtain an aluminum alloy having the aforementioned limited structure by carrying out first and second heat treatments on gas-atomized powder containing at least 10 vol. % of an amorphous phase or a green compact thereof and thereafter carrying out hot plastic working.

Abstract: An aluminum alloy powder or a green compact thereof is prepared, wherein: (1) the composition formula is Al.sub.100-a-b Fe.sub.a X.sub.b where a and b in atomic % are 4.0.ltoreq.a.ltoreq.6.0, 1.0.ltoreq.b.ltoreq.4.0, and where X is at least one alloy element selected from Y and Mm (mish metal); or (2) the composition formula is Al.sub.100-a-b-c Fe.sub.a Si.sub.b X.sub.c, where a, b and c in atomic % are 3.0.ltoreq.a.ltoreq.6.0, 0.5.ltoreq.b.ltoreq.3.0, and 0.5.ltoreq.c.ltoreq.3.0, and where X is at least one alloy element selected from Ti, Co, Ni, Mn and Cr, and wherein both (1) and (2) include an amorphous phase of at least 1% by volume. The aluminum alloy powder or the green compact thereof is heated at a temperature increasing at a rate of at least 80.degree. C./min. to a predetermined temperature of at least 560.degree. C. and not more than a temperature at which 10% by volume of a liquid phase is contained in the alloy powder or green compact.

Abstract: A hyper-eutectic aluminum-silicon powder containing extremely fine primary crystal silicon, is prepared by atomizing. First, a molten metal of a hyper-eutectic aluminum-silicon alloy containing phosphorus is prepared. This molten metal or melt is atomized with air or an inert gas and quench-solidified. Aluminum-silicon alloy powder containing primary crystal silicon of not more than 10 .mu.m in crystal grain size is obtained. This aluminum-silicon alloy powder contains at least 12 percent by weight and not more than 50 percent by weight of silicon and at least 0.0005 percent by weight and not more than 0.1 percent by weight of phosphorus. When this hyper-eutectic aluminum-silicon alloy powder is employed, it is possible to prepare a consolidate of powder which has improved mechanical properties, and provides a high yield.

Abstract: The object is to provide a method of degassing or solidifying an aluminum alloy powder by utilizing an induction heating as a degassing means in a step of forming and solidifying an aluminum powder or aluminum alloy powder, whereby the disadvantages of the prior art can be overcome. The feature of the present invention consists in preforming an aluminum powder, aluminum alloy powder or aluminum composite alloy powder or mixed powders thereof with non-metallic grains to give a specific electric resistance of at most 0.2.OMEGA.cm, subjecting the preform directly to induction heating in an atmosphere at normal pressure, temperature-raising to 400.degree. to 600.degree. C. at a temperature gradient of at least 0.4.degree. C./sec in a temperature range of at least 300.degree. C. and removing heat-decomposable volatile components to obtain a hydrogen content of at most 10 ppm.

Abstract: An aluminum alloy is melted and sprayed from a nozzle. Solid particles of silicon are sprayed by gas jet simultaneously with spraying of the aluminum alloy. Both the sprayed aluminum alloy and the sprayed solid particles of silicon are deposited and cooled.

Abstract: Tuning apparatus including a scale provided with indicia corresponding to different broadcast frequencies to which the tuning apparatus is tunable and a pointer movable across the scale to indicate the particular broadcast frequency to which the tuning apparatus is tuned. The pointer is supported by a movable support which is guided by a guide shaft. A plurality of markers are slidably guided along at least one guide rail and are individually settable to desired locations adjacent the scale, thereby representing particular broadcast frequencies to which the tuning apparatus is tunable. A key removably mounted on the guide shaft is bi-directionally driven therealong by the movable support, the key being selectively operative to engage a desired one of the markers to move the engaged marker along the guide rail as the support is moved, whereby the marker is set to a desired position by reason of its engagement with the key.