| 摘要 |
PROBLEM TO BE SOLVED: To prevent damage due to an excessive load and reduction of durability of a pitching cylinder when a combine travels with a switching valve of the pitching cylinder set to be neutral, in the combine including a horizontality maintaining hydraulic circuit adjusting a front/rear inclination of a vehicle body with the pitching cylinder.SOLUTION: When a pitching valve 36 switching supply of a motion oil to a pitching cylinder 5 to telescopic motion is set to be neutral, flow of working fluid of an extension side fluid passage and a contraction side fluid passage between the pitching cylinder 5 and the pitching valve 36 is blocked. A relief valve 57 connecting the extension side fluid passage to the contraction side fluid passage and releasing the motion oil at a predetermined pressure is arranged.SELECTED DRAWING: Figure 3 |
