| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hydraulic circuit of an option device for an excavator capable of supplying always constant flow regardless of large or small load generated in driving the option device such as a breaker and regulating each flow demanded in various option devices. <P>SOLUTION: The hydraulic circuit of the option device for the excavator comprises a first spool 15 controlling the flow supplied to the option device 24 from a hydraulic pump 26; a poppet 14 controlling the flow supplied to the option device from the hydraulic pump, and a piston 13 elastically supported to a back pressure chamber 17 of the poppet; an option spool 25 controlling an operating fluid passing through the first spool and supplied to the option device; a second spool 3 switched by the difference between pressure on the first spool inlet side and the added pressure of pressure on the first spool outlet side and resilience of a valve spring 5 to control the flow supplied to the back pressure chamber of the poppet; and a control means for regulating the flow passing through an orifice 14a of the poppet. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
