Sealing apparatus used in a wire cut electric discharge machine

#1. Field of Invention

#The invention relates to a wire cut electric discharge machine that performs electric discharge machining on a workpiece placed fixedly in a machining tank and, more particularly, to a wire cut electric discharge machine that performs electric discharge machining using a wire electrode stretched between an upper arm disposed at an upper portion of a machining tank and a lower arm slidably inserted into the machining tank.

#2. Description of Related Art

#The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:

#FIG. 1 is a front view showing a general structure of a wire cut electric discharge machine according to a first embodiment of the invention;

#FIGS. 2A-2C are sectional views each showing a seal structure, for use in the wire cut electric discharge machine, according to the first embodiment of the invention;

#Preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a front view showing the general structure of the wire cut electric discharge machine according to a first embodiment of the invention. In the wire cut electric discharge machine, a wire electrode 30 is supported between a pair of rollers and fed toward a workpiece W as the rollers rotate.

#As shown in FIG. 1, a machining tank 33 is placed on a base 32 of the wire cut electric discharge machine. The workpiece W is fixedly placed on a worktable 34, which is fixed to the machining tank 33, and is immersed in an electrically insulative machining fluid (fresh water or a mixture of fresh water and oil) 35. The machining fluid 35 is supplied from a machining fluid supply device 99. The machining fluid 35, contaminated due to the electric discharge machining of the workpiece W, is returned to the machining fluid supply device 99, filtered, and recycled. An XY table 36, which is movable on an X-Y plane, is disposed between the base 32 and the machining tank 33, and is driven by a driving mechanism (not shown).

#A wire bobbin 39, around which the wire electrode 30 is wound, is provided at an upper portion of a column extending vertically from the base 32. An upper nozzle 41 is attached to an upper arm 40, which is supported at an upper portion of the column 37, while an lower nozzle 43 is disposed at a lower arm 42, which is supported at a lower portion of the column 37.