摘要:
A hydraulic drive system includes a pump control unit 18 for controlling a pump delivery rate such that a pump delivery pressure is held at a predetermined value higher than a maximum load pressure among actuators 2-6. Pressure compensating valves 12-16 are each constructed to set, as a target compensation differential pressure, a differential pressure between the delivery pressure of a hydraulic pump 1 and the maximum load pressure among the actuators 2-6. The pressure compensating valve 12 is given such a load dependent characteristic that the target compensation differential pressure is reduced when a load pressure rises. A lower limit setting spring 55 for limiting the target compensation differential pressure from becoming smaller than a predetermined value is provided in the pressure compensating valve 12 for the swing section.
摘要:
An actuator lock switching valve 50 is provided which communicates a drain line 52 and a pilot line 53 with each other when the valve 50 is in a position C, and which communicates pilot lines 51, 53 with each other when it is shifted to a position D. The pilot line 51 is connected to a delivery line 7 of a hydraulic pump 10, and the pilot line 53 is connected to pressure receiving sections 28a, 28b provided at ends of the pressure compensating valves 21a, 21b on the side acting in the closing direction. The actuator lock switching valve 50 has a pressure receiving section 55 connected to the output side of a pilot lock switching valve 43, and is switched over in interlock with shifting of the switching valve 43. In a hydraulic drive system including pressure compensating valves controlled by an LS system, an actuator can be locked with a simple construction and can be prevented from malfunctioning in an inoperative condition while an engine is being driven, even when the system includes a mechanically shifted directional control valve, or even when a mechanically shifted directional control valve is retrofitted to the system.
摘要:
A hydraulic drive system having a swing control system, includes a pump control unit for controlling a pump delivery rate such that a pump delivery pressure is held a predetermined value higher than a maximum load pressure among a plurality of actuators. Pressure compensating valves are each constructed to set, as a target compensation differential pressure, a differential pressure between a delivery pressure of a hydraulic pump and a maximum load pressure among the actuators. A pressure compensating valve for a swing section is given such a load dependent characteristic that when the load pressure rises, the target compensation differential pressure is reduced, the load dependent characteristic being set so as to provide a flow rate characteristic simulating constant-horsepower control of a swing motor.
摘要:
In a hydraulic drive system in which a target compensated differential pressure for each of pressure compensating valves 21a, 21b is set in accordance with a differential pressure between a pump delivery pressure and a maximum load pressure, and a target LS differential pressure is set as a variable value depending on a revolution speed of an engine 1, a fixed throttle 32 and a signal pressure variable relief valve 33 are disposed in a maximum load pressure line 35. A relief setting pressure PLMAXO of the signal pressure variable relief valve 33 is set so as to satisfy PLMAXO=PR−PGR+a (where a is a value smaller than PGR) with respect to a target LS differential pressure PGR and a setting pressure PR of the main relief valve 30.
摘要:
A photovoltaic device includes a silicon substrate of a first conduction type that includes an impurity diffusion layer on one surface side; a light-receiving-surface side electrode that includes a plurality of grid electrodes electrically connected to the impurity diffusion layer; and a back-surface side electrode formed on the other surface side of the silicon substrate wherein the impurity diffusion layer includes a first impurity diffusion layer and a second impurity diffusion layer, and wherein the first impurity diffusion layer is formed so that a direction perpendicular to a longitudinal direction of the grid electrodes is a longitudinal direction thereof, and so that an area ratio of the first impurity diffusion layer to a band region is equal to or lower than 50%.
摘要:
A hydraulic device comprises a variable displacement pump, a plurality of hydraulic actuators, a plurality of directional valves capable of controlling the delivery oil flowing into each of the actuators, a plurality of pressure compensation valves which compensate the pressures of respective directional valves, and a delivery oil flow rate varying means capable of controlling the pump delivery. At least one of the pressure compensation valves decreases its output flow to a particular actuator according to an increase in the loaded pressure of the particular actuator. With this arrangement, if the loaded pressure of the particular actuator suddenly changes, the loaded pressure attenuates to ensure stable operation of the hydraulic device. Further, the stable operation is fee of hunting for both low-load actuators and high load actuators, regardless of an independent operation or a compound operation.
摘要:
In a method of producing a thin-film solar cell, a graphite sheet in which the breaking stress in a thickness direction is smaller than the breaking stress in a direction perpendicular to the thickness direction is adhered to a heat resistant substrate, a semiconductor thin film is formed on the graphite sheet in a high temperature process, a second substrate for supporting the semiconductor thin film is adhered to the semiconductor thin film, and the graphite sheet is broken by applying a mechanical stress to the heat resistant substrate and the second substrate. The semiconductor thin film is reliably supported by the heat resistant substrate during high temperature processing and easily removed from the heat resistant substrate by breaking the graphite sheet. In addition, since the graphite sheet has an anisotropic breaking stress, fragments of the graphite sheet remaining on the surface of the semiconductor thin film are easily removed. As a result, a high quality thin film solar cell is produced reliably at low cost.
摘要:
A manufacturing method includes a step of forming an impurity diffusion layer by diffusing an impurity element in a surface of a silicon-based substrate; and an etching step of removing the impurity diffusion layer in at least a portion of a first-surface side of the silicon-based substrate, wherein the etching step includes an etching-fluid supplying step of, on the first-surface side, supplying an etching fluid that flows to an outer edge portion of the silicon-based substrate from a supply position, and an air supplying step of, on a second-surface side, which is opposite to the first-surface side, of the silicon-based substrate, supplying air in a same direction as the etching fluid in accordance with supply of the etching fluid at the etching-fluid supplying step.
摘要:
A spool valve comprises a slidable spool, and through displacement of the spool a supply port of the valve is allowed to communicate with one of the load ports of the valve while the other load port is allowed to communicate with a corresponding one of return ports of the valve. The spool is provided with a portion, the outside diameter of which gradually increases, at least on the other load port side from the center of a central concave portion of the spool. The outside diameter gradually increasing portion decreases fluid force which acts against an operating force of the spool when the valve is activated.
摘要:
In a semiconductor device having a polycide structure located on a stepped portion, halation during formation of a resist pattern is prevented, and oxidation of an upper surface of a high-melting-point metal silicide layer is prevented during formation of an interlayer insulating film on the polycide structure. In this semiconductor device, an upper layer which is formed of one layer selected from the group consisting of an amorphous silicon layer, a polycrystalline silicon layer, a TiN layer and a TiW layer is formed on the high-melting-point metal silicide layer forming the polycide structure. This effectively suppresses reflection of light beams by the upper layer located at the stepped portion during exposure for forming the resist pattern on the upper layer. Thereby, formation of a notch at the resist pattern is prevented, and the resist pattern is accurately formed to have a designed pattern. The upper layer made of the amorphous silicon layer or polycrystalline silicon layer prevents formation of an oxide layer at an upper surface of the high-melting-point metal silicide layer due to oxydation by Oxygen carried to the inside of the CVD furnace from the outside during formation of an interlayer insulating film covering the polycide structure.