| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide construction machinery capable of simplifying the constitution of a drain passage and enhancing the efficiency of draining work. <P>SOLUTION: The construction machinery have a hydraulic tank 5, a changeover valve 7 opening/closing a pilot line of a hydraulic control system controlling actuation of machinery. The construction machinery is constituted so that the return oil from the changeover valve 7 is returned from the bottom of the hydraulic tank 5. A drain pipe 7g is branched in a position disposed lower than the hydraulic tank 5 in the return pipe 10. A plug 7h opening/closing the drain pipe 7g is installed at the outlet of the drain pipe 7g. When the outlet is opened by the plug 7h, the oil in the hydraulic tank 5 can be discharged through the return pipe 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
