| 摘要 |
<p>PROBLEM TO BE SOLVED: To incinerate and remove particulate matter deposited at a diesel particulate collection filter utilizing increased temperature of exhaust gas caused by an increased engine load.SOLUTION: Selector valves 23a, 23b in pathways extending from center bypass circuits 18a, 18b to shuttle valves 21a, 21b are closed through operation of a switch 25 to thereby avoid a transmittance of a negative control pressure from the center bypass circuits 18a, 18b to the shuttle valves 21a, 21b and at the same time the shuttle valves 21a, 21b are changed over to the operating state by selector valves 22a, 22b, and at that time, a pilot pressure supplied from a pilot pressure adjusting valve 10 is transmitted to negative control segments 7a, 7b to thereby cause the pilot pressure input to the negative control segments 7a, 7b to be decreased and a pump discharging amount of variable capacity pumps 3a, 3b to be increased and then particulate matter at a diesel particulate collection filter 24 is incinerated and removed by increasing exhaust gas temperature.</p> |
