Abstract: To reduce load on the operator and to establish traveling stability in the steering operation of a construction machine that has a pair of right and left traveling devices, and an engine as a driving power to the right and left traveling devices, a controller is provided which is responsive to a switch for traveling to drive or stop both a right and a left traveling devices. A switch for steering causes the controller to change the direction of travel of the construction machine, and the controller also acts to reduce the engine speed in accordance with the operation amount of the switch for steering.

Abstract: An automatic swing device for a work machine is capable of performing a sieve operation in the posture where a work device is always at a posture suitable for sieve operation. An automatic swing device includes a posture sensor that detects a posture of a work device, and a controller that outputs signals to operate at least a stick cylinder and a bucket cylinder of the work device. The controller has an automatic swing mode in which the work device is automatically swung while the posture detected by the posture sensor is maintained to be in the range of a predetermined posture.

Abstract: Provided is a work machine which is capable of accurately preventing a work device from interfering with a load receiving member without separately using a dedicated device. A work machine includes a controller which at least controls rotating of an upper rotating body and vertical movement of a boom in accordance with operation by an operator. The controller controls either a boom-up operation and a rotating operation of the upper rotating body such that a work device is prevented from interfering with a load receiving member in operation of an operator at subsequent lifting and rotating, operation based on part of a locus at a distal end side of the work device at least for one lifting and rotating operation.

Abstract: Provided is a work machine which is capable of accurately preventing a work device from interfering with a load receiving member without separately using a dedicated device. A work machine includes a controller which at least controls rotating of an upper rotating body and vertical movement of a boom in accordance with operation by an operator. The controller controls either a boom-up operation and a rotating operation of the upper rotating body such that a work device is prevented from interfering with a load receiving member in operation of an operator at subsequent lifting and rotating, operation based on part of a locus at a distal end side of the work device at least for one lifting and rotating operation.

Abstract: To reduce load on the operator and to establish traveling stability in the steering operation of a construction machine that has a pair of right and left traveling devices, and an engine as a driving power to the right and left traveling devices, a controller is provided which is responsive to a switch for traveling to drive or stop both a right and a left traveling devices. A switch for steering causes the controller to change the direction of travel of the construction machine, and the controller also acts to reduce the engine speed in accordance with the operation amount of the switch for steering.

Abstract: Provided is an automatic swing device for a work machine which is capable of performing sieve operation in the posture where a work device is always at a posture suitable for sieve operation. An automatic swing device includes a posture sensor (15) which detects a posture of a work device. The automatic swing device also includes a controller (37) which outputs signals to operate at least a stick cylinder (12st) and a bucket cylinder (12bk) of the work device. The controller (37) has an automatic swing mode in which the work device is automatically swung while the posture detected by the posture sensor (15) is maintained to be in the range of a predetermined posture.

Abstract: The machine includes an operation selection switch to choose either an oil-pressured pilot operation or an electric operation, a control device to input an electric signal for traveling transmitted from an electric operation device and a selection signal from the operation selection switch. A third electro-magnetic valve may forbid outputting pilot pressure from a pilot valve, a first to fourth electro-magnetic proportional valve outputting a pilot pressure to the control valve for traveling based on the control signal from the control device and a first to fourth shuttle valve leading the output pilot pressure to the control valve for traveling.