| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a warming-up system, that can prevent a response delay of a pilot pressure control valve when an air temperature is low, by warming of a valve body including the pilot pressure control valve, and can prevent the valve body from heating beyond necessity. <P>SOLUTION: The warming-up system includes pilot pressure control valves 34, 79, and 80 for controlling pressure of pilot oil sent to a supply target, and the valve body 35 thereof. The valve body includes a heat-up oil path w formed to penetrate the valve body, the heat-up oil path is communicated with the discharge port of a pump P2. On the downstream side of the heat-up oil path, a heat-up valve 52 is disposed to supply pilot oil flowing out from the heat-up oil path to a hydraulic oil tank 31 to heat up the valve body when the temperature of pilot oil is low, and limits the flowing of pilot oil flowing from the heat-up oil path to the hydraulic oil tank to prevent the valve body from being heated up more than necessary when the pilot oil is warmed by a predetermined temperature or more. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
