PROBLEM TO BE SOLVED: To minimize such a state that a work device is not maintained in a target attitude even when its attitude is rapidly varied in a structure for varying the work-device attitude of a working vehicle provided with an attitude control means for operating an actuator so as to maintain the target attitude.SOLUTION: The structure includes an attitude detection means for detecting the attitude of a work device 5, and a varying speed-detection means for detecting the speed of attitude variation of the work device 5. Besides, the structure includes the attitude control means for maintaining the work device 5 in the target attitude by operating the actuator 4 at high speeds based on a first control gain as the detected value of the attitude detection means deviates from the target one, and operating at high speeds based on a second control gain as the detected value of the varying speed-detection means becomes high speeds. A control gain-changing means capable of changing the second control gain is further provided.COPYRIGHT: (C)2009,JPO&INPIT【課題】 作業装置が目標姿勢に維持されるようにアクチュエータを作動させる姿勢制御手段を備えた作業車の作業装置姿勢変更構造において、作業装置の姿勢が急速に変化した場合、作業装置が目標姿勢に維持されていない状態をできるだけ少なく(短く)する。【解決手段】 作業装置5の姿勢を検出する姿勢検出手段と、作業装置5の姿勢変化の変化速度を検出する変化速度検出手段とを備える。姿勢検出手段の検出値が目標姿勢から外れるほど、アクチュエータ4を第1制御ゲインに基づいて高速で作動させ、変化速度検出手段の検出値が高速になるほど、アクチュエータ4を第2制御ゲインに基づいて高速で作動させて、作業装置5を目標姿勢に維持する姿勢制御手段を備える。第2制御ゲインを変更可能な制御ゲイン変更手段を備える。【選択図】 図1
