Hydraulic circuit for heavy equipment

专利名称：Hydraulic circuit for heavy equipment发明人：Koo, Bon Seok申请号：EP08016279.5申请日：20080916公开号：EP2039943A2公开日：20090325

专利附图：

摘要：A hydraulic circuit for heavy equipment is provided, which can prevent signalpressure exceeding a predetermined pressure from being formed in a pilot signal path(11) provided in a switching valve to sense whether the switching valve has been shifted ina hydraulic system that minimizes the discharge flow rate of a hydraulic pump when a

working device such as a boom is not driven. The hydraulic circuit includes first to fourthhydraulic pumps (P1,P2,P3,P4) connected to an engine, first switching valves (1,2) installedin flow paths of the first hydraulic pump (P1) and shifted to control hydraulic fluid fed toa working device, second switching valves (4,5,6) installed in flow paths of the secondhydraulic pump (P2) and shifted to control hydraulic fluid fed to a working device, thirdswitching valves (7,8) installed in flow paths of the third hydraulic pump (P3) and shiftedto control hydraulic fluid fed to a swing device, a pilot signal path (11) for sensingwhether the first to third switching valves are shifted, a throttling part (10) installed inthe pilot signal path (11) to form a signal pressure, and a valve (21) installed in a parallelflow path branch-connected to the pilot signal path and supplying the signal pressure inthe pilot signal path (11) to the pilot signal pressure supply path (22) when a signalpressure exceeding a predetermined pressure is formed in the pilot signal path (11).

申请人：Volvo Construction Equipment Holding Sweden AB

地址：631 85 Eskilstuna SE

国籍：SE

代理机构：Dr. Weitzel & Partner

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