| 摘要 |
PURPOSE:To prevent increase in room temperature in an electric spark machine room and occurrence of a trouble in wave propagation by placing a cooling equipment at the outside of an electromagnetically shielded room and making a coupling signal line between a machine main body and the cooling equipment room run through an electric current propagating means of a high-frequency, non-conductivity type which is installed in the vicinity of an outer wall of the said shielded room. CONSTITUTION:An electric spark machine 1 and a working liquid tank 2 are placed in an electric spark machine room 3 that is electromagnetically shielded, while a cooling equipment 4 for working liquid cooling is placed outside the room 3. As a result, inevitable increase in room temperature in the room 3 can be prevented. Meanwhile, an electric current propagating means 5 of a high-frequency, non-conductivity type such as a relay or a photo-coupler is installed on an outer wall of the rom 3. A signal line 8 between the cooling equipment 4 and the spark machine 1 in addition to between the cooling equipment 4 and a driving motor 7 of a working liquid circulating pump 6 is relayed through the electric current propagating means 5. Accordingly, although electromagnetic waves caused by electric sparks do incident on the portion of the signal line 8, which is located in the room 3, the electromagnetic waves thus incidented into the signal line 8 do radiate from the signal line 8 at the outside of the room 3, thereby preventing a trouble in wave propagation from occurring. |
