| 摘要 |
PURPOSE:To simplify operation, control and structure by providing a spring which exhibits resilient supporting performance when the height of body is lowered through a control cylinder and does not exhibit resilient supporting performance when the body height is made high. CONSTITUTION:The lower end section of the piston section 42 of a control support cylinder 5 is fixed to an axle case 7, and a spring 9 is placed between a support case 6 and the axle case 7. When a tractor travels on a pavement, oil is removed from the control support cylinder 5 to shorten the cylinder 5 then the support case 6 is moved downward along a transmission shaft 8 thus lowering the body. At this time, the support case 6 and the body are supported through the spring 9 on the axle case 7 with shock being absorbed. When work is performed, the control support cylinder 5 is extended hydraulically to move the support case 6 upward through the transmission shaft 8 thus increasing the body height. At this time, resiliency of the spring 9 does not function because of the enlarged gap between the axle case 7 and the support case 6. |
