Abstract: A working mechanism (4) takes a traveling stance by a way that left and right boom cylinders (9, 10) are expanded to rotate a tip end of a first boom (5) to the rear side and a positioning cylinder (11) is compressed to rotate a tip end of a second boom (6) to the lower side. In the traveling stance of the working mechanism (4), a front surface plate (23A) of a right front housing cover (23) is inclined along a tilting angle (?) of the left and right boom cylinders (9, 10), and the front surface plate (23A) of the right front housing cover (23) is arranged in a position of lining with front ends (9A1, 10A1) of tubes (9A, 10A) in the left-right direction forming the respective boom cylinders (9, 10).

Abstract: A hydraulic control device for work machine includes: a driving device that generates a driving force for traveling of the work machine; a park braking device that parks the work machine; an operating unit that is provided in a cab of the work machine and operated by an operator for driving a work device; a hydraulic brake device that generates a braking force according to operation of a brake pedal; a hydraulic lock unit that hydraulically locks the hydraulic brake device to cause the hydraulic brake device to be continuously operated; a work device drivable state judging unit that judges whether or not the work device is in a work device drivable state in which the work device can be driven; and a park brake control unit that brings the park braking device into operation when the hydraulic lock unit hydraulically locks the hydraulic brake device and the work device drivable state judging unit judges that the work device drivable state has not been established.

Abstract: A hydraulic control device for work machine includes: a driving device that generates a driving force for traveling of the work machine; a park braking device that parks the work machine; an operating unit that is provided in a cab of the work machine and operated by an operator for driving a work device; a hydraulic brake device that generates a braking force according to operation of a brake pedal; a hydraulic lock unit that hydraulically locks the hydraulic brake device to cause the hydraulic brake device to be continuously operated; a work device drivable state judging unit that judges whether or not the work device is in a work device drivable state in which the work device can be driven; and a park brake control unit that brings the park braking device into operation when the hydraulic lock unit hydraulically locks the hydraulic brake device and the work device drivable state judging unit judges that the work device drivable state has not been established.

Abstract: A working mechanism (4) takes a traveling stance by a way that left and right boom cylinders (9, 10) are expanded to rotate a tip end of a first boom (5) to the rear side and a positioning cylinder (11) is compressed to rotate a tip end of a second boom (6) to the lower side. In the traveling stance of the working mechanism (4), a front surface plate (23A) of a right front housing cover (23) is inclined along a tilting angle (?) of the left and right boom cylinders (9, 10), and the front surface plate (23A) of the right front housing cover (23) is arranged in a position of lining with front ends (9A1, 10A1) of tubes (9A, 10A) in the left-right direction forming the respective boom cylinders (9, 10).

Abstract: A prime mover control device of a construction machine includes a hydraulic pump (24) driven by a prime mover (10), an actuator (5) driven with pressure oil discharged from the hydraulic pump (24), and a control valve (25) that controls a flow of the pressure oil from the hydraulic pump (24) to the actuator (5) in response to an operation of a first operating member (22a).

Abstract: The present invention includes: a hydraulic pump 10 that is driven by a driving motor; a travel motion motor 12 that is driven with pressure oil supplied from the hydraulic pump 10; a travel motion control valve 11 that controls a flow rate of the pressure oil supplied from the hydraulic pump 10 to the travel motion motor 12; a means for operation 22a with which the travel motion control valve 11 is operated; a means for rotation rate detection 95 that detects a rotation rate N of the travel motion motor 12; and a means for motor over rotation prevention 14, 17, 32 that reduces the rotation rate of the travel motion motor 12 if the means for rotation rate detection 95 detects a rotation rate equal to or higher than a predetermined rotation rate upper limit Nmax.

Abstract: A construction machine according to the present invention includes a variable displacement hydraulic pump (11, 12) driven by a prime mover (10), a single traveling actuator (5) driven with pressure oil discharged from the hydraulic pump (11), a plurality of work actuators (2a, 4d to 4f) driven with the pressure oil discharged from the hydraulic pump (11, 12), a plurality of control valves (13 to 17) that control flows of the pressure oil from the hydraulic pump (11) to each of the traveling actuator (5) and the plurality of work actuators (2a, 4d to 4f), a detection means (24) for detecting a drive command for the traveling actuator (5), and a flow rate control means (11a, 30, 40, 43) for increasing a maximum flow rate of the hydraulic pump (11) when the drive command for the traveling actuator (5) is detected with the detection means (24).

Abstract: A control apparatus of a construction machine includes a hydraulic pump driven by a prime mover, a hydraulic actuator, and a rotation speed detection device for detecting an actual rotation speed of the prime mover. The control apparatus includes a prime mover control device for controlling a rotation speed of the prime mover, and an input torque control device for adjusting an input torque for the hydraulic pump based on a deviation between the actual rotation speed detected by the rotation speed detection device and a control rotation speed set through an operation of the operating device, and the input torque control device executes control to decrease the input torque if the control rotation speed is greater than the actual rotation speed and the deviation calculated by subtracting the control rotation speed from the actual rotation speed is smaller than a predetermined negative value.

Abstract: The present invention includes a hydraulic pump (11), a variable displacement hydraulic motor (5) for traveling driven by pressure oil from the hydraulic pump (11), a motor displacement control means (17, 18) for adjusting a displacement of the hydraulic motor (5) in correspondence to a drive pressure at the hydraulic motor (5), an operating member (22) through which a forward travel command and a backward travel command for the vehicle are issued, a control means (12) to be driven in response to an operation of the operating member (22), for controlling a flow of pressure oil from the hydraulic pump (11) to the hydraulic motor (5), a reverse operation detection means (41A, 41B) for detecting a reverse operation of the operating member (22) performed to a reverse side opposite from a direction along which the vehicle is advancing, and a cavitation preventing means (25A,25B) engaged in operation so as to prevent occurrence of cavitation at the hydraulic motor (5) when the reverse operation at the operating mem

Abstract: The present invention includes a hydraulic pump 10 driven by a prime mover 1, a traveling motor 12 driven with pressure oil delivered from the hydraulic pump 10, a control valve 11 for traveling that controls a flow rate of the pressure oil delivered from the hydraulic pump 10 to the traveling motor 12, a counterbalance valve 13 switched in response to a motor load pressure supplied via the control valve 11, that generates a braking pressure at a conduit L1A or L1B disposed on a return side of the traveling motor 12 as the load pressure becomes lower, an overspeed detection means 42 for detecting an overspeed state in the traveling motor 12, and a motor overspeed inhibiting means 50 for inhibiting rotation of the traveling motor 12 if the overspeed detection means 42 detects an overspeed state in the traveling motor 12 until a braking pressure is generated through a switchover at the counterbalance valve 13 and the traveling motor 12 is no longer in the overspeed state.

Abstract: The present invention includes:a hydraulic pump 10 that is driven by a driving motor; a travel motion motor 12 that is driven with pressure oil supplied from the hydraulic pump 10; a travel motion control valve 11 that controls a flow rate of the pressure oil supplied from the hydraulic pump 10 to the travel motion motor 12; a means for operation 22a with which the travel motion control valve 11 is operated; a means for rotation rate detection 95 that detects a rotation rate N of the travel motion motor 12; and a means for motor over rotation prevention 14, 17, 32 that reduces the rotation rate of the travel motion motor 12 if the means for rotation rate detection 95 detects a rotation rate equal to or higher than a predetermined rotation rate upper limit Nmax.

Abstract: A prime mover control device of a construction machine according to the present invention includes a hydraulic pump (11) driven by a prime mover (40), a hydraulic traveling motor (5) driven with pressure oil output from the hydraulic pump (11), and a control valve (12) that controls a flow of the pressure oil from the hydraulic pump (11) to the hydraulic motor (5) in response to an operation of an operating member (22a).

Abstract: The present invention includes a hydraulic pump 10 driven by a prime mover 1, a traveling motor 12 driven with pressure oil delivered from the hydraulic pump 10, a control valve 11 for traveling that controls a flow rate of the pressure oil delivered from the hydraulic pump 10 to the traveling motor 12, a counterbalance valve 13 switched in response to a motor load pressure supplied via the control valve 11, that generates a braking pressure at a conduit L1A or L1B disposed on a return side of the traveling motor 12 as the load pressure becomes lower, an overspeed detection means 42 for detecting an overspeed state in the traveling motor 12, and a motor overspeed inhibiting means 50 for inhibiting rotation of the traveling motor 12 if the overspeed detection means 42 detects an overspeed state in the traveling motor 12 until a braking pressure is generated through a switchover at the counterbalance valve 13 and the traveling motor 12 is no longer in the overspeed state.

Abstract: The wheeled work vehicle according to the present invention has a link that links at least either one of the axles and provided at the front and the rear of the vehicle to a body, suspension hydraulic cylinders provided at the left side and the right side of the chassis to link the axle to the body in conjunction with the link and an accumulator that is made to communicate with oil chambers and of the hydraulic cylinders via restrictors.

Abstract: A prime mover control device of a construction machine includes a hydraulic pump (24) driven by a prime mover (10), an actuator (5) driven with pressure oil discharged from the hydraulic pump (24), and a control valve (25) that controls a flow of the pressure oil from the hydraulic pump (24) to the actuator (5) in response to an operation of a first operating member (22a).

Abstract: A prime mover control device of a construction machine according to the present invention includes a hydraulic pump (11) driven by a prime mover (40), a hydraulic traveling motor (5) driven with pressure oil output from the hydraulic pump (11), and a control valve (12) that controls a flow of the pressure oil from the hydraulic pump (11) to the hydraulic motor (5) in response to an operation of an operating member (22a).

Abstract: The present invention includes a hydraulic pump (11), a variable displacement hydraulic motor (5) for traveling driven by pressure oil from the hydraulic pump (11), a motor displacement control means (17, 18) for adjusting a displacement of the hydraulic motor (5) in correspondence to a drive pressure at the hydraulic motor (5), an operating member (22) through which a forward travel command and a backward travel command for the vehicle are issued, a control means (12) to be driven in response to an operation of the operating member (22), for controlling a flow of pressure oil from the hydraulic pump (11) to the hydraulic motor (5), a reverse operation detection means (41A, 41B) for detecting a reverse operation of the operating member (22) performed to a reverse side opposite from a direction along which the vehicle is advancing, and a cavitation preventing means (25A,25B) engaged in operation so as to prevent occurrence of cavitation at the hydraulic motor (5) when the reverse operation at the operating mem

Abstract: A control apparatus of a construction machine according to the present invention includes a variable displacement hydraulic pump (10) driven by a prime mover (20), a hydraulic actuator (5) driven with pressure oil discharged from the hydraulic pump (10), and a rotation speed detection means (31) for detecting an actual rotation speed (Nr) of the prime mover (20).