摘要:
A construction machine comprising a lower carriage (12); a working attachment (17) attached rotatably to an upper rotating structure (14); and posture detecting means for detecting a posture of the working attachment, characterized in that the construction machine has a control circuit comprising: a rotating direction control valve (29) for controlling rotation of the upper rotating structure; an unloading valve being a cut-off valve (33) adapted for opening and closing motions to control bleed-off of said rotating direction control valve (29), wherein an outlet of a center bypassing oil path for return of a main pressure oil, said center bypassing path extending through a neutral position of said rotating direction control valve (29), and an oil tank (32) are in communication with each other through said cut-off valve (33); a controller (16) adapted to control opening and closing of said cut-off valve (33) on the basis of detection signals from said posture detecting means and rotating operation detecting means (42L,42R), said controller (16) providing an operation command signal to an electromagnetic proportional pressure controlling valve (35) in such a manner that an operation command pilot pressure is provided to said pilot port (34) of the cut-off valve (33).
摘要:
The invention relates to a composition comprising from 20 to 70 parts by weight of poly[ethylene terephthalate] (PET), from 20 to 70 parts by weight of poly[ethylene naphthalate] (PEN) and from 10 to 33 parts by weight of poly[butylene terephthalate] (PBT), the total being 100 parts by weight, in the form of a polymer blend and/or copolymer.
摘要:
A wire rod for drawing which is superior in drawability as well as twisting characteristics, and a method for producing the wire rod. The wire rod is characterized in that the raw material thereof is a eutectoid steel or hypereutectoid steel containing 0.1-2.0mass% Si and 0.2-2.0mass% Mn and the pearlite structure therein accounts for no less than 80area% of microstructure and the maximum length of ferrite as the second phase therein is no larger than 10 µm. The wire rod is produced by drawing with a true strain of 1.5 or above and subjecting the wire rod to patenting at a heating temperature defined by a specific equation.
摘要:
Disclosed is a sheathing material for a construction machine and a method for producing the same, in which lightweighting can be attained without using a reinforcing member, and which is not greatly flexed even if a load is applied. The sheathing material for a construction machine which is lightweighted and has a flexure rigidify is obtained by molding a resined shell (1d) having a hollow construction by rotational molding, filling a resin foamed body (1e) such as a hard polyurethane foam within the resined shell (1d) to set it, thereby providing a sandwiching construction, and adjusting filling density of the resin foamed body (1e).
摘要:
A construction machine having an oil cooler 3, a radiator 4, and a fan shroud 5 arranged in an upper rotating body 13, in which the oil cooler 3 and the fan shroud 5 are securely fixed to the upper rotating body 13 and the radiator 4 is adapted to be detachably fixed to the upper rotating body 13 while the oil cooler 3 and the fan shroud 5 are held in the state fixed to the upper rotating body 13.