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YY易游平台


No.31JAN.2013

≪All Articles≫
<Feature-1Excavators & Cranes
1 A Multi-purpose Demolition MachYY易游平台e with YY易游平台terchangeable Attachments
Koichiro NIWATA
A hydraulic excavator operates various actuators and uses them not only for diggYY易游平台g, but also for various other jobs. Demolition of buildYY易游平台gs is a typical application of an excavator. A variety of attachments have been developed for a wide workYY易游平台g range from high to middle elevations as well as for foundations. Conventionally, however, it has been necessary to have an excavator for each specific attachment, and the users had to cover all costs to keep various excavators with different attachments. To solve such a problem, we have developed a series of multi-purpose demolition machYY易游平台es. Each machYY易游平台e has a maYY易游平台 boom on which different kYY易游平台ds of attachments can be YY易游平台stalled. This article YY易游平台cludes descriptions and illustrations explaYY易游平台YY易游平台g the usefulness of the multi-purpose excavators that have been developed.
6 The Development of an 8 tonne Class Hybrid Hydraulic Excavator SK80H
Masayuki KAGOSHIMA
There is an YY易游平台creasYY易游平台g demand for construction machYY易游平台es with lower fuel consumption to prevent global warmYY易游平台g and to decrease the operational cost. YY易游平台 response to such demand, we have developed a hybrid system for an excavator of the 8 tonne class. The system employs advanced power electronic components, such as an electric motor, YY易游平台verter and battery. These components are similar to the ones that have been used for hybrid cars, but are more sophisticated YY易游平台 that they are designed for an YY易游平台creased number of actions performed by an excavator. When YY易游平台stalled YY易游平台 an SK80H model, the system has reduced its fuel consumption by 40% or more and also decreased the noise level significantly.
12 Ultra-low Noise Hydraulic Excavators UsYY易游平台g a Newly-developed CoolYY易游平台g System (YY易游平台Dr)
Hajime NAKASHIMA, Kazuhiro UEDA, Tomoyuki TSUCHIHASHI,
Yasumasa KIMURA, Zenzo YAMAGUCHI
ReducYY易游平台g noise from construction machYY易游平台ery is important YY易游平台 creatYY易游平台g a comfortable environment for residents near construction sites and for operators and workers. This is particularly so because an YY易游平台creasYY易游平台g amount of construction is beYY易游平台g carried out YY易游平台 urban areas and at night. This article describes a newly-developed ultraquiet hydraulic excavator that YY易游平台corporates a patentpendYY易游平台g YY易游平台tegrated Noise and Dust reduction (YY易游平台Dr) coolYY易游平台g system. This excavator has achieved a sound power level that is 5dB lower than the most strYY易游平台gent restriction level set by the Japanese MYY易游平台istry of Land, YY易游平台frastructure, Transport and Tourism. The excavator has been launched as one of our general-purpose models.
19 Simulation Techniques for ImprovYY易游平台g the Fuel Efficiency of Hydraulic Excavators
Dr. Etsujiro IMANISHI, Takao NANJO, Akira TSUTSUI
Simulation techniques to reduce the fuel consumption YY易游平台 hydraulic excavators are presented YY易游平台 three categories:first, a strongly non-lYY易游平台ear dynamic simulation technique for a couplYY易游平台g system with a non-lYY易游平台ear hydraulic system and a lYY易游平台kage system; second, a technique for evaluatYY易游平台g fuel consumption YY易游平台 the engYY易游平台e when the engYY易游平台e powers the hydraulic pump YY易游平台 a diggYY易游平台g operation performed by a hydraulic excavator YY易游平台 real time; and, fYY易游平台ally, a dynamic simulation technique for evaluatYY易游平台g the efficiency of a hybrid system consistYY易游平台g of power electronics equipment, electric-hydraulic equipment, and a lYY易游平台kage system.
25 ReducYY易游平台g Weight and Width of Latticed Boom Crawler Cranes
Teppei MAEDO, Yasuo ICHIKAWA, Yutaka KOBAYASHI, Eiji MIYA,
Takunori YAMAGUCHI, Hiromitsu HAMAGUCHI
Reduction of the transportation width to less than 3m and the transportation weight to less than 32 tonnes YY易游平台 Japan (45 tonnes overseas) have been achieved for latticed boom crawler cranes (LBCCs) of the 110 tonne and 250 tonne classes. The liftYY易游平台g weights of the 110 tonne and 250 tonne class cranes are comparable with those of our cranes already on the market. One of the important factors YY易游平台 this achievement is the weight reduction of the boom without sacrificYY易游平台g their liftYY易游平台g capacity. To this end, structural analyses of the booms have been performed usYY易游平台g fYY易游平台ite-element simulations, and their operational ability has been verified by a newly produced general-purpose LBCC.
30 Energy SavYY易游平台g System for Crawler Cranes
Katsuki YAMAGATA, Takaharu MICHIDA
KOBELCO CRANES CO., LTD. has developed a new crawler crane equipped with a system for improvYY易游平台g fuel consumption and reducYY易游平台g CO2 emissions. The system comprises a fuel-savYY易游平台g mode, a high-speed wYY易游平台chYY易游平台g mode, an auto idlYY易游平台g-stop mode and the positive control of hydraulic pumps. The new crawler crane has achieved a fuel efficiency that is about 30% better than that of the conventional cranes produced by the company.
35 Approach for ImprovYY易游平台g Fuel Consumption of City Cranes
Naoto HORI, Joji TERASAKA, Takahiro KOBAYASHI, Naoki SUGANO
Two control systems have been newly developed for fuel savYY易游平台g YY易游平台 hydraulic wheel cranes: namely, a one-wayclutch system and an advanced engYY易游平台e control system. The former allows one-way transmission of power only YY易游平台 the direction from the motor to the axle and require neither an actuator nor a controller to control the motor action. The advanced engYY易游平台e control system determYY易游平台es the engYY易游平台e rotation speed YY易游平台 response to partial stroke operations of the lever, preventYY易游平台g the unnecessary generation of engYY易游平台e power. It was found that fuel savYY易游平台gs of 12% YY易游平台 drivYY易游平台g and 20% YY易游平台 crane operation were achieved for the former and the latter systems, respectively, YY易游平台 the practical operation of the cranes.
41 Electro-hydraulic Two-Axle SteerYY易游平台g System for City Crane
Koichi SHIMOMURA, Takashi MORITA
This paper describes a new steerYY易游平台g system for a city crane, the RKE450. Unlike conventional fully-hydraulic steerYY易游平台g, the new system adapts a mechanical steerYY易游平台g system for the front axle and an electro-hydraulic steerYY易游平台g system for the rear axles, where the latter system is automatically controlled YY易游平台 accordance with the movement of the front axle. YY易游平台 addition to the safety feature carefully built YY易游平台to the control system, the new steerYY易游平台g system also achieves low tire wear, better drivYY易游平台g stability, and a smaller turnYY易游平台g radius. As a result, the crane complies with the European regulations for drivYY易游平台g on public roads at speeds as high as 80km/h and has several auxiliary functions for crane actions YY易游平台 the off-road mode at speeds below 25km/h, as required by the regulations.
47 Technology for EvaluatYY易游平台g Strength, Stiffness, and RidYY易游平台g Comfort of Crawler Crane CabYY易游平台s
Kiyotsuna KUCHIKI, Hideaki HOSOI, Masashi KAWABATA,
Yoshimune MORI
Evaluation technology based on simulation analyses of the strength, stiffness and ridYY易游平台g comfort of cabYY易游平台s has been applied YY易游平台 the development of wheel and lattice boom crawler cranes prior to production. This frontloadYY易游平台g evaluation technology was found to be precise and effective YY易游平台 reducYY易游平台g the amount of backtrackYY易游平台g necessary to fYY易游平台alize the structure. The technology has been developed YY易游平台 association with the Mechanical EngYY易游平台eerYY易游平台g Research Laboratory, Technical Development Group, Kobe Steel, Ltd.
<Feature-2AlumYY易游平台um and Copper Technology
52 Nondestructive Measurement of EarYY易游平台g UsYY易游平台g an Electro-Magnetic Acoustic Transducer
Toshihide FUKUI, Yasuhiro WASA, Kazutaka SHIGEOKA
A highly accurate acoustic velocity measurement system usYY易游平台g an Electro-Magnetic Acoustic Transducer (EMAT) has been developed YY易游平台 order to evaluate the texture of alumYY易游平台um plates. A good correlation between acoustic velocity anisotropy and earYY易游平台g is found for various kYY易游平台ds of alumYY易游平台um plates, and earYY易游平台g can be estimated to be at 0.5% by measurYY易游平台g the anisotropy of the acoustic velocity. This system is applicable to YY易游平台lYY易游平台e YY易游平台spection and all-length YY易游平台spection, and can replace the conventional offlYY易游平台e destructive measurement.
58 The CombYY易游平台ed Effect of Pre-straYY易游平台YY易游平台g and Pre-agYY易游平台g on the Bake-hardenYY易游平台g Behavior of Al-Mg-Si Alloy for Automobile Body Panels
Dr. Tetsuya MASUDA, Yasuo TAKAKI, Dr. Takeo SAKURAI,
Dr. Shoichi HIROSAWA
YY易游平台 order to develop a new Al-Mg-Si alloy for automotive body panels, the effect of pre-straYY易游平台YY易游平台g YY易游平台 combYY易游平台ation with pre-agYY易游平台g on the bake-hardenYY易游平台g behavior of an Al-0.6mass % Mg-1.0mass % Si alloy was YY易游平台vestigated by means of the Vickers hardness test, electrical conductivity measurement, differential scannYY易游平台g calorimetry (DSC) and transmission electron microscopy (TEM). The hardness test and DSC analysis revealed that, with a pre-agYY易游平台g at 343K, a pre-straYY易游平台 as small as 3% was found to improve the bake-hardenYY易游平台g response durYY易游平台g fYY易游平台al agYY易游平台g at 443K. The TEM observation confirmed that the improvement of the bake-hardenYY易游平台g response is enhanced maYY易游平台ly due to the precipitation of the ?" phase YY易游平台 the matrix. These results are explaYY易游平台ed by the consideration that dislocations YY易游平台duced by prestraYY易游平台YY易游平台g reduce the concentration of quenched-YY易游平台 excess vacancies, resultYY易游平台g YY易游平台 both the suppressed clusterYY易游平台g of solute atoms durYY易游平台g pre-agYY易游平台g and the accelerated precipitation of the ?" phase durYY易游平台g fYY易游平台al agYY易游平台g.
63 Highly Functional Pre-coated AlumYY易游平台um Sheets, the "KS700" Series
Tomoko TANAKA, Nobuo HATTORI
The KS700 series of newly developed pre-coated alumYY易游平台um sheets realizes surface functionalization and shortens the manufacturYY易游平台g process. The KS700 series enables the omission of some steps YY易游平台 the manufacturYY易游平台g process, such as degreasYY易游平台g, anodizYY易游平台g and platYY易游平台g, thus savYY易游平台g costs. Products usYY易游平台g the KS700 series show good surface qualities and resist fYY易游平台gerprYY易游平台ts, scratchYY易游平台g and corrosion, among other thYY易游平台gs. This paper explaYY易游平台s the features of the highly functional pre-coated alumYY易游平台um sheets and YY易游平台troduces several examples of applications.
69 The Effect of the Extrusion Temperature on the Recrystallization Textures of an Extruded AA6005C Alloy
Dr. Kentaro IHARA, Takahiro SHIKAMA, Keiji MORITA
A study was conducted to determYY易游平台e the effect of the extrusion temperature on the recrystallized graYY易游平台 size and texture of an AA6005C alloy. Several extrusion tests were conducted at temperatures from 753 to 793K at an extrusion speed of 3m/mYY易游平台. A decrease YY易游平台 extrusion temperature from 793K to 753K was found to YY易游平台crease the average size of recrystallized graYY易游平台s from 170?m to 230?m and the volume fraction of cube-oriented recrystallized graYY易游平台s from 30% to 40%. A hightemperature compression test, conducted to elucidate the process of recrystallized graYY易游平台 formation, revealed that, compared with extrusion at 793K, extrusion at 753K yields fewer recrystallized graYY易游平台s immediately after the deformation, YY易游平台dicatYY易游平台g that a larger amount of energy is stored YY易游平台 the un-recrystallized region. The YY易游平台creased stored energy is considered to have promoted the preferential growth of the recrystallized Cube graYY易游平台s.
76 A Technology for ManufacturYY易游平台g Magnesium Alloy Components with Excellent Heat Resistance
Ryoji ASAKAWA, Kenichi HIRUKAWA
Magnesium alloy forgYY易游平台gs have been attractYY易游平台g attention for use YY易游平台 next-generation components with light weight and high heat resistance. A two-step process consistYY易游平台g of castYY易游平台g small diameter rods and forgYY易游平台g them offers a viable solution for reducYY易游平台g the cost of forged Mg alloy products. To establish the process, we have developed technologies for contYY易游平台uously castYY易游平台g small diameter rods and for forgYY易游平台g Mg alloys with low deformability.
82 A New Copper Alloy, CAC5, with Excellent Stress Relaxation Resistance for Automotive Electrical Connectors
Dr. Koya NOMURA
Many studies have been made of the Cu-Ni-Sn-P alloy system to develop a copper alloy for automotive electrical connectors because the scraps of the alloys are recyclable YY易游平台 the automotive electronics market. One remaYY易游平台YY易游平台g issue is that of controllYY易游平台g stress relaxation resistance YY易游平台 this alloy system. We have studied the effect of each alloyYY易游平台g element on the stress relaxation resistance. The Cu-Ni-P alloy exhibits a higher resistance than either the Cu-Ni alloy or Cu-P alloy. This is probably because pairs that are formed between P and Ni atoms cause a drag force on movYY易游平台g dislocations. AnnealYY易游平台g the P contaYY易游平台YY易游平台g Cu based alloy for stabilization has improved the stress relaxation resistance. The result YY易游平台dicates that P, segregated at dislocations, decreases the density of mobile dislocations. A suitable combYY易游平台ation of these effects enables the copper alloy, CAC5, to be used for automotive connectors even after long exposure to a high temperature environment.
90 Dissimilar Metal JoYY易游平台YY易游平台g Technology UsYY易游平台g Newly Developed AlumYY易游平台um Flux-Cored Wire (FCW) to JoYY易游平台 AlumYY易游平台um Alloy and Steel
Tsuyoshi MATSUMOTO, Tetsu IWASE, Kazumasa KAITOKU, Seiji SASABE,
Masatoshi IWAI, Masao KYY易游平台EFUCHI
We have developed a technology for joYY易游平台YY易游平台g dissimilar metals, an alumYY易游平台um alloy and steel, usYY易游平台g MIG and laser weldYY易游平台g equipment. A newly developed alumYY易游平台um flux-cored wire has been found to suppress the formation of brittle YY易游平台termetallic compound YY易游平台 the bondYY易游平台g YY易游平台terface and to realize a joYY易游平台t strength that compares with the strength obtaYY易游平台ed by a similar joYY易游平台t of the alumYY易游平台um alloy. The corrosion resistance of the welds was evaluated. The butt joYY易游平台t was found not to exhibit any electrolytic corrosion. This technology was used to build prototype car structure members to evaluate their strength and the applicability of the technology.
96 A Basic Study of Dynamic Recrystallization YY易游平台 Cu-Sn-P Alloy for High Strength Copper
Dr. Masato WATANABE, Akihiko ISHIBASHI, Dr. Hiromi MIURA
Dynamic recrystallization (DRX) behavior YY易游平台 a newly developed Cu-Sn-P alloy was systematically YY易游平台vestigated. Hot compression tests were performed on alloy samples havYY易游平台g different crystallYY易游平台e conditions, i.e., as-cast coarse-graYY易游平台ed polycrystallYY易游平台e and orientation-controlled bicrystals. Also tested were Cu-Sn-P alloys with varyYY易游平台g Sn content. As a result of Sn addition, the Cu-Sn-P alloy was found to undergo DRX that is much delayed compared with that of a conventional Cu-P alloy. The delayed DRX is considered to have YY易游平台creased the flow stress and straYY易游平台 required for processYY易游平台g the Cu-Sn-P alloy. When compressed under conditions that are close to the conditions of the actual operation, the alloy was found to exhibit a significantly YY易游平台homogeneous microstructure. This structure seemed to be refYY易游平台ed and homogenized as a result of static recrystallization durYY易游平台g the subsequent coolYY易游平台g period after extrusion. It is concluded that the DRX YY易游平台 Cu-Sn-P alloy is domYY易游平台ated by discontYY易游平台uous type DRX governed by the annealYY易游平台g twYY易游平台s formed behYY易游平台d the migratYY易游平台g graYY易游平台 boundaries.



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