Abstract: A method of controlling a wire-cut electric discharge machine to improve machining accuracy in a machining operation for a corner portion of a workpiece to be machined. In a case where the portion to be machined includes a corner, a pressure and/or an amount of machining fluid supplied to a gap between the workpiece and a wire electrode is decreased only in a specified section. The setting of this specified section and adjustment of the machining fluid is carried out on the basis of an allowable discrepancy amount, and shape and size of the corner. Furthermore, in addition to decreasing electric discharge energy supplied between the workpiece and the wire electrode, the machining fluid may be adjusted within the specified region.

Abstract: A machining fluid device for a wire cut electric discharge machine, which controls the amount of machining fluid supplied from upper and lower nozzles to values suited to different machining modes including first and second machining modes. The device includes a machining fluid supply source having first and second supply lines connected to the upper nozzle and third and fourth supply lines connected to the lower nozzle. Selector means selectively permit supply of machining fluid through the first to fourth supply lines. In the first machining mode, the machining fluid is supplied from the upper and lower nozzles through the first and third supply lines at flow rates suited to the first machining mode and in the second machining mode, the machining fluid is supplied through the second and fourth supply lines at flow rates suited to the second machining mode.

Abstract: A wire-cut electric discharge machining method which is capable of preventing damage which may be caused when electric discharge machining is interrupted due to a shortage of wire supply in the middle of a certain machining section, so as to improve the quality of products. A central processing unit compares a residual wire length with a consumed wire length necessary for machining associated with each block of a machining program, and successively determines whether the machining for each block can be completed. If it is concluded that the machining cannot be completed, a warning message is displayed, and the electric discharge machining is stopped when the machining associated with the block currently in execution is finished. In consequence, the electric discharge machining is interrupted at a bending position of a machining path, so that the machined surface of a workpiece never suffers damage which entails lowering of product quality.

Abstract: A bearing cooling system for a water turbine having a rotatable shaft connected at one end to a movable blade portion and supported by a journal bearing and by a thrust bearing having a collar, comprises a heat pipe including a first container surrounding and spaced from the rotatable shaft and extending axially from a predetermined engaging position adjacent the one end of the shaft to the journal and thrust bearings. The thrust bearing engages the outer surface of the first container, and the shaft and thrust bearing and inner surface of the container define walls of a sealed first chamber surrounding a portion of the rotatable shaft and communicating with the journal and thrust bearings. The system is adapted to include a fluid contained in the first chamber for absorbing heat generated by the journal and thrust bearings. A second container is spaced from and surrounds a portion of the first container adjacent the one end of the shaft.

Abstract: An apparatus for uniforming the heat of a gun barrel includes an heat-pipe type dissipation cylinder attached to an outer periphery of the gun barrel along the longitudinal direction thereof for uniforming the heat of the barrel, and a heat insulating cover coating the heat-pipe type dissipation cylinder for covering an outer periphery thereof and shading the heat-pipe type dissipation cylinder from solar radiation.

Abstract: A gun barrel structure for a tank having improved heat dissipation properties and accordingly improved accuracy. The gun barrel of the tank is surrounded by a cylindrical heat pipe containing a working fluid. The heat pipe may be constituted by concentric inner and outer cylinders with the working fluid therebetween, or by a single cylinder surrounding the gun barrel with the working fluid held between the outer surface of the gun barrel and the inner surface of the cylinder. Preferably, the heat pipe is divided into a plurality of separate sections disposed along the barrel. A wick holding the working fluid may also be employed.