Abstract: The construction vehicle is provided with an engine, a clutch, a travel device, a work equipment, a drive force setting dial, and a controller that includes: a theoretical value determination unit that determines a theoretical value, for the degree of engagement to make the upper limit value of the drive force equal to a set drive force; an operational state determination unit that determines whether the work equipment is outputting the drive force in a predetermined travel direction; a drive force determination unit that determines whether the drive force is greater than the set drive force; and a degree of engagement reduction unit that, if of operational state determination and of drive force determination are both affirmative, causes the degree of engagement to approach the theoretical value.

Abstract: The construction vehicle is provided with an engine, a clutch, a travel device, a work equipment, a drive force setting dial, and a controller that includes: a theoretical value determination unit that determines a theoretical value, for the degree of engagement to make the upper limit value of the drive force equal to a set drive force; an operational state determination unit that determines whether the work equipment is outputting the drive force in a predetermined travel direction; a drive force determination unit that determines whether the drive force is greater than the set drive force; and a degree of engagement reduction unit that, if of operational state determination and of drive force determination are both affirmative, causes the degree of engagement to approach the theoretical value.

Abstract: A control device for working machines capable of controlling the moving of a tool continuously over a wide range, and capable of moving it accurately along a desired path. Out of not less than three control shafts (3a, 4a, 5a), a first combination of two control shafts (3a, 5a) is selected, and a bucket (6) is moved in a first section (A-B) out of travelling path thereof with the driving of the two selected shafts (3a, 5a) controlled. A second combination of two control shafts (3a, 4a) which is different from the selected first combination of two control shafts (3a, 5a) is then selected, and the bucket (6) is moved in a second section (B-C), which is continuous from the first section (A-B), with the driving of the two selected shafts (3a, 4a) controlled.

Abstract: A construction machinery having a first boom 1 rotatably mounted on a vehicle frame, a second boom 4 rotatably mounted on the first boom 1, a first boom cylinder 2 connecting the vehicle frame 3 and the second boom 4, and a second boom cylinder 5 connecting the second boom 4 and the first boom 1, characterized in that it is arranged in such a way that the drive of the working machines in the new link mechanism is controlled simply and with high precision by indicating the position or the velocity of the working machine leading end by subjecting a working machine leading end target value to coordinate conversion to the target angles for the first and second boom angles, determining the target cylinder length for the first boom cylinder 2 from the target angles for the first and second boom angles obtained by the coordinate conversion, and driving the first boom cylinder 2 according to the target cylinder length.

Abstract: Even when a bucket is changed to an optional special bucket, path control as intended by an operator can be automatically performed without making a correction of the angle of the original bucket. For this purpose, in an operation mode determining section (9), there is calculated the possibility (U2) of an operation mode being a nose-fixed mode, depending on how much a bucket attitude angle (.gamma.) deviates from a predetermined angle, and there is also calculated the possibility (U1) of the operation mode being the fixed-angle to the ground mode, depending on the magnitude of a computed value of the allowable angle held with respect to the ground, whereby the operation mode during the automatic path control can be automatically determined by comparing these possibilities (U1, U2).