PROBLEM TO BE SOLVED: To simplify a configuration, improve operation ability, and perform draft control in which sensitivity can be adjusted.SOLUTION: A tractor performs position control by actions of a first link mechanism 19 for linking a spool 17A of a control valve 17 to a height setting lever 18 and a feedback link mechanism 20 for linking the spool 17A to a lift arm 15, and performs draft control by actions of a second link mechanism 22 for linking the spool 17A to a load detection member 21, and the feedback link mechanism 20. A sensitivity adjustment mechanism 23 changes a gap S between an oscillation arm 30 of the first link mechanism 19 and an operation arm 39 of the second link mechanism 22, in linkage to an operation of a sensitivity adjustment lever 44 located on an operation part, for adjusting operation sensitivity of the spool 17A in the draft control.SELECTED DRAWING: Figure 2
