Abstract: An industrial machine and a method of controlling an industrial machine, the industrial machine including a dipper supported by a dipper handle. The method may include determining an operating phase of the industrial machine, in a first operating phase of the industrial machine, limiting, with at least one controller, a reach of the dipper handle, and in a second operating phase of the industrial machine, enabling, with the at least one controller, an extended reach of the dipper handle greater than the reach in the first operating phase. The industrial machine may include at least one controller configured to determine an operating phase of the industrial machine, in a first operating phase of the industrial machine, limit a reach of the dipper handle, and, in a second operating phase of the industrial machine, enable an extended reach of the dipper handle greater than the reach in the first operating phase.

Abstract: A traction force control section of a wheel loader reduces maximum traction. force to below the maximum traction. force with traction force control in an off state when the traction force control is in an on state. The traction force control section increases the maximum traction force when determination conditions are satisfied with the traction force control in the on state. The determination conditions include that the work situation is digging, that the operation amount of the acceleration operation member is the predetermined operation threshold or more, and that a boom angle is the predetermined angle threshold or more.

Abstract: A traction force control section of a wheel loader, when the determination conditions are satisfied during traction force control, increases the maximum traction force. The determination conditions include that the aspect of operation is excavation, that the vehicle speed is less than or equal to a prescribed speed threshold value, that the amount of operation of the accelerator operating member is equal to or more than a prescribed accelerator threshold value, and that the amount of operation of the inching operating member is less than or equal to a prescribed inching operation threshold value.

Abstract: A mining machine includes a base, a boom, a member, and a dipper. The base includes a frame portion that is rotatable relative to the support surface about a machine axis. The boom includes a first end coupled to the base, a second end opposite the first end, and a sheave coupled to the second end of the boom. A first distance is defined between the machine axis and the second end of the boom. The member is movably coupled to the boom about a pivot point that is positioned substantially between the first end and the second end of the boom. A second distance is defined between the machine axis and the pivot point. A ratio of the second distance to the first distance is between 27% and 43%. The dipper is coupled to an end of the member and is supported by a hoist rope.

Abstract: A tractive force control part of a wheel loader reduces the maximum tractive force when determination conditions are satisfied during tractive force control. The determination conditions include that the work phase is excavation, that the working implement is in the raising hydraulic stall condition and that drive circuit pressure is greater than or equal to a predetermined pressure threshold.

Abstract: A material handling apparatus is described including a vehicle having a front end, a rear end, a left side, a right side, a chassis, and a ground engagement device attached to the chassis for providing movement of the vehicle across ground; an engine constructed for propelling the vehicle; a loader assembly; a hydraulic system constructed for driving the loader assembly; and operator area including a cage for protecting an operator located within the operator area, and controls for controlling movement of the vehicle and for controlling operation of the loader assembly; and a forward tools area extending from the operator seating area to the front end of the vehicle. The material handling apparatus can include an entrance to the operator area through the rear end of the vehicle, a loader assembly that includes a tower that rotates relative to the chassis, and a dump box or work platform provided in the forward tools area. A method for operating a material handling apparatus is provided.

Abstract: Positional relationship among the first link support shaft (85), the second link support shaft (86), the first arm support shaft (88) and the second arm support shaft (89) is set such that an upper portion of the first lift link (81) comes into substantial agreement with a rear end of the machine body (1), when the upper free end of the first lift link (81) is pivoted maximally rearward in the course of transition of the arm (77) from a lowermost state realized lifting down the arm (77) to an uppermost state realized by lifting up the arm (77).

Abstract: A working machine rendered to change in setting a maximum value of an absorption torque of hydraulic pump to a rather high value when the working machine is in a specified state, solves problems that, when an operation lever is being operated in an intermediate position of a lever stroke, there occurs a swinging in a machine body due to change-over of a maximum absorption torque setting value so that the operation lever is relatively moved with respect to the machine body to exert an influence on operability and the machine body acting violently. When the maximum absorption torque setting value is E2 position which is good fuel efficiency, upon detection of a full operation of either one or both of the travelling operation member and the boom operation member, controlling to automatically switch to E1 position of a maximum absorption torque larger than that of E2 position is performed.

Abstract: A work vehicle includes an engine, a throttle opening degree setting unit, first and second hydraulic pumps driven by the engine, a travel hydraulic motor driven by hydraulic fluid discharged from the first hydraulic pump, a work implement driven by hydraulic fluid discharged from the second hydraulic pump. A first control unit is configured to determine a work phase of the work implement and to set an upper limit for the throttle opening degree in accordance with the work phase. A second control unit is configured to control output of the engine based on the smaller of the throttle opening degree set by the throttle opening degree setting unit and the throttle opening degree set by the first control unit.

Abstract: A backhoe loader includes cab, a loader, an engine, and a backhoe. The loader includes a pair of loader arms sandwiching the engine from the side, a loader bucket, and a loader bucket cylinder. There is provided a foot mount member attached at the outer side of the loader arm to be horizontal relative to the ground in a state where the bottom of the loader bucket is in contact with the ground. Thus, a backhoe loader of favorable workability in the maintenance service of engine can be obtained.

Abstract: A lifting vehicle having two axles with respective differentials; a constant-velocity, universal joint drive connecting the differentials; a telescopic arm; and a hydraulic circuit powered by a hydraulic pump to operate the telescopic arm.

Abstract: A pod disposal system has a pod holder for holding a coffee pod; a moveable chamber including an engaging member for engaging with the coffee pod, and an ejector operably connected to the engager for disengaging the coffee pod from the engager, An actuator moves the moveable chamber between an engaging position, in which the engager engages with the coffee pod, an intermediate position, in which the moveable chamber moves the coffee pod out of the pod holder, and a disengaging position, in which the ejector disengages the coffee pod from the engager, thereby disposing the coffee pod.

Abstract: Systems, methods, devices, and computer readable media for controlling the operation of an industrial machine including one or more components. A method of controlling the industrial machine includes determining a position of at least one of the one or more components of the industrial machine during a digging operation, determining a hoist bail pull setting based on the position of the at least one of the one or more components and a relationship between component position and hoist bail pull, and setting a level of hoist bail pull to the hoist bail pull setting. The level of hoist bail pull early in the digging operation is greater than the level of hoist bail pull later in the digging operation.

Abstract: A monitor system for an electric cable shovel determines when the shovel has completed a digging operation, and a subsequent dumping operation. The system includes an inclinometer, a current sensor, and a monitor circuit. The inclinometer is mounted on the dipper arm for providing an output indicative of the inclination of the dipper arm. The current sensor senses the level of the electrical current supplied to the electric motor. The monitor circuit determines when the current sensor provides an indication of a current level in excess of a digging current threshold level for a period of time in excess of a predetermined period, and during such period of time the inclinometer indicates that the inclination of the dipper arm is below a digging threshold inclination. In such a case, the monitor circuit provides an output indicating that the shovel has completed a digging operation.

Abstract: [Problem] To provide a hybrid work vehicle which is simple in configuration, good in ease of mounting on a vehicle and capable of efficiently transmitting motive power. [Solution] The hybrid work vehicle includes: an engine (1); a hydraulic pump (4) which is driven by the engine; a work device (5) which is disposed at the front of the vehicle and performs work using the hydraulic pump as a drive source; a motor/generator (6) which generates electric power by use of the torque of the engine; and a travel drive device which causes the vehicle to travel by rotating and driving wheels by use of the electric power generated by the motor/generator. The hybrid work vehicle is steered while the vehicle bends by way of a center joint (15). The travel drive device includes: a plurality of electric motors (21 and 22); and a propeller shaft (8) which is linked with the plurality of electric motors and transmits motive power from the plurality of electric motors to the wheels.

Abstract: A skid steer loader having an operator compartment attached to a frame. Lift assemblies are movably mounted to the frame and are movable between a retracted position and an extended position. As the lift assemblies are moved between the retracted position and the extended position, joining plates, first links and second links are positioned behind the operator compartment to provide a better field of vision for the operator.

Abstract: Systems, methods, devices, and computer readable media for controlling a digging operation of an industrial machine. A method includes determining a hoist bail pull associated with the industrial machine, determining a crowd torque limit value for a crowd drive based on the determined hoist bail pull of the industrial machine, and setting a crowd torque limit of the crowd drive to the crowd torque limit value to limit a torque associated with a crowd motor to the crowd torque limit value.

Abstract: A sensor assembly is disclosed for a pin connection of a machine linkage, such as that found on an excavator or backhoe loader, the sensor assembly including a sensor associated with a sensor housing that receives the pin, and a connector assembly that connects the sensor housing to a frame element, wherein the connector assembly is configured to allow the sensor housing to move relative to the frame element. The sensor assembly may be positioned within one of the members of the linkage.

Abstract: Determining dipper geometry. A method of determining dipper geometry includes obtaining a first set of data associated with an industrial machine for a first orientation of the industrial machine, and obtaining a second set of data associated with the industrial machine for a second orientation of the industrial machine. The first set of data includes at least one of a first length associated with a hoist rope and a first angle associated with the hoist rope, and the second set of data includes at least one of a second length associated with the hoist rope and a second angle associated with the hoist rope. The value of the physical characteristic of the dipper is then determined based on the first set of data and the second set of data.

Abstract: A machine such as a wheel loader includes a frame and ground engaging propulsion elements coupled with the frame. A hydraulically actuated implement system of the machine includes a linkage and an implement and is adjustable from a starting configuration to a second configuration according to a substrate collision avoiding pattern. In the second configuration, the implement hovers above a substrate beneath the machine. Related methodology and control logic is also disclosed.

Abstract: A hybrid wheel loader includes: an engine that includes an output shaft; a motor/generator that includes a rotating shaft directly attached to the output shaft of the engine; a transmission that includes an input shaft attached to the rotating shaft of the motor/generator, and an output shaft; a propeller shaft disposed on an output side of the transmission and driven via the output shaft of the transmission; an electricity storage device; and a control device that stores electricity into the electricity storage device by collecting electrical energy at the motor/generator.

Abstract: An object detection system (24) is disclosed having a transducer (40, 40?) for detecting buried objects (26). The transducer is encapsulated within a robust, electromagnetically transparent construction (42).

Abstract: A hydraulic pump, electric motor, inverter, oil tank, heat exchanger, and battery are mounted on a revolving frame, and are covered by an exterior cover. The revolving frame is provided with a partition plate, and the interior of the exterior cover is partitioned by the partition plate into a machine room for accommodating the hydraulic pump and the electric motor and into a battery room for accommodating the battery. A cooling fan is arranged in the machine room so that outside air is introduced into the machine room through an oil tank cooling air inlet port and an inverter cooling air inlet port which are provided in the exterior cover. This outside air cools the hydraulic pump, the electric motor, and the oil tank in the machine room and is exhausted to the outside of the machine room through an exhaust port.

Abstract: Systems, methods, and devices for controlling an industrial machine. The industrial machine includes, for example, a dipper, a boom, a hoist motor, a crowd motor, one or more operator control devices, and a controller. The control devices are configured to be manually controllable by an operator of the industrial machine. The controller receives an output signal associated with a desired movement of the dipper, receives a signal associated with a hoist motor characteristic, and receives a signal associated with a crowd motor characteristic. The controller determines a present position of the dipper with respect to a boom profile, determines a first future position of the dipper with respect to the boom profile and based on the output signal from the operator control devices, and automatically controls a movement of the dipper with respect to the boom profile when the first future position of the dipper approximately corresponds to a boom profile limit.

Abstract: A machine includes a frame having ground engaging propulsion elements coupled therewith, and a hydraulically actuated implement system having a linkage, an implement coupled with the linkage, and a hydraulic actuator coupled with the linkage. The machine further includes a control system having an electronic control unit configured to receive an implement down force control command, and responsively adjust a pressure of hydraulic fluid in the hydraulic actuator such that the implement rests with controlled down force upon a substrate below the machine. The controlled down force may be less than a quiescent down force of the hydraulically actuated implement system. Related methodology is also disclosed.

Abstract: A robot includes a rotating electrical machine and a brake. The brake is configured to restrict rotation of the rotating electrical machine. The brake includes a brake plate, a plurality of pressing members, at least one biasing member, and an electromagnetic coil. The brake plate is configured to rotate integrally with a shaft of the rotating electrical machine. The plurality of pressing members are movable toward the brake plate and include a first pressing member and a second pressing member. The at least one biasing member is configured to bias the first pressing member and the second pressing member toward the brake plate using mutually different biasing forces. The electromagnetic coil is configured to, when current is on, electromagnetically attract the first pressing member and the second pressing member against the biasing forces of the at least one biasing member.

Abstract: A working machine hydraulic circuit, including: a hydraulic motor; a pilot pressure system configured to supply hydraulic fluid at a pilot pressure to one or more components of the working machine; and a make-up pressure system in hydraulic fluid communication with the pilot pressure system and the hydraulic motor, and configured to supply hydraulic fluid to the hydraulic motor from the pilot pressure system if the hydraulic fluid pressure in a part of the hydraulic motor is below a threshold pressure such that, during deceleration of the hydraulic motor, the make-up pressure system is operable to supply fluid from the pilot pressure system to the hydraulic motor to reduce the risk of cavitation in the hydraulic motor.

Abstract: A method of analyzing minerals received within a mining shovel bucket includes collecting data associated with ore received in the bucket, where the bucket includes at least one active sensor, where the ore includes one or more mineral, and where the ore is within a field of the active sensor. The method further includes determining a content of the minerals using the data, transmitting information relating to the content of the minerals to a decision support system, and sorting or processing the ore based on an output of the decision support system. Collecting data associated with the ores may include generating source signals, applying the source signals to the active sensor, collecting a response from the active sensor, and comparing the response with a reference or threshold. Other features are disclosed.

Abstract: Systems, methods, devices, and computer readable media for controlling a digging operation of an industrial machine that includes a dipper and a crowd drive. A method includes determining an acceleration associated with the industrial machine, determining a crowd retract factor based on the acceleration, comparing the crowd retract factor to a threshold crowd retract factor, setting a crowd speed reference and a crowd retract torque for the crowd drive for a period of time based on the comparison of the crowd retract factor to the threshold crowd retract factor.

Abstract: A hydraulic control system for a machine is disclosed. The hydraulic control system may have a work tool movable through segments of an excavation cycle, a motor configured to swing the work tool during the excavation cycle, at least one accumulator configured to selectively receive fluid discharged from the motor and to discharge fluid to the motor during the excavation cycle, and a controller. The controller may be configured to receive input regarding a current excavation cycle of the work tool, and make a determination based on the input that the current excavation cycle is associated with one of a set of known modes of operation. The controller may be further configured to cause the at least one accumulator to receive fluid and discharge fluid during different segments of the excavation cycle based on the determination.

Abstract: A construction machine includes a negative parking brake whose braking state is released by a supply of hydraulic fluid. It also includes a parking brake hydraulic circuit that is branched from a hydraulic fluid supplying circuit, which supplies the hydraulic fluid to a transmission of the construction machine, and supplies the hydraulic fluid to the parking brake. The parking brake hydraulic circuit includes a check valve that prevents backflow of the hydraulic fluid of the parking brake to the hydraulic fluid supplying circuit, and it includes an operation switching valve, which is provided closer to the parking brake than the check valve, for switching between an activation and a release of the parking brake. The parking brake hydraulic circuit also includes a relief valve, which is interposed between the check valve and the operation switching valve and which discharges the hydraulic fluid of the parking brake when the relief valve is opened.

Abstract: A hood for a loader work machine is provided at the rear end of the frame body and downwardly of the transverse connecting member between the pair of right/left support frame members. The transverse connecting member includes a front wall plate and an upper wall plate projecting rearward from an upper end of the front wall plate. The upper wall plate of the transverse connecting member is disposed more downwardly than the vertical center of the cabin. A rear portion of the upper wall plate is inclined downwardly rearward. A hood upper wall is provided for covering a rear upper side between the pair of right/left support frame members. A front end portion of the hood upper wall is connected to the rear portion of the upper wall plate of the transverse connecting member. The hood upper wall is inclined downwardly rearward in correspondence with the rear portion of the upper wall plate.

Abstract: An apparatus, system, and method for measuring, in accordance with a standard measure, any of a fractional part, whole and multiple of a quantity of chopped wood, such as firewood, for delivery to a customer are provided. The apparatus may be a bucket having one or more markers disposed thereon, using one or more measurement scales adapted to at least one of the bucket size, chopped wood size, and measurement system, where the markers indicate the quantity of chopped wood contained in the bucket. The apparatus may further comprise an attachment section to allow the apparatus to be attached to a vehicle to transport the apparatus. The method may include filling the apparatus to the markers with a plurality of pieces of chopped wood, delivering the chopped wood to a customer, and providing the customer with an assurance that the quantity of chopped wood is accurate.

Abstract: A shovel includes an engine; a hydraulic pump driven by the engine; an attachment including a boom, the attachment being driven with hydraulic fluid discharged by the hydraulic pump; a motor generator configured to assist driving by the engine; an electric power accumulating part configured to accumulate electric power generated by the motor generator; a motion state detecting part configured to detect the motion state of the attachment; and an assist control part configured to control the execution of an assist by the motor generator using the electric power accumulated in the electric power accumulating part. The assist control part is configured to cause the motor generator to assist the engine during a boom raising motion after an excavation motion.

Abstract: An apparatus, method and sensor apparatus for determining a spatial positioning of loading equipment is disclosed. The loading equipment has an operating implement for loading a payload, the operating implement being coupled to a support for movement relative to the support. The apparatus includes an orientation sensor disposed on the support and being operable to produce an orientation signal representing an orientation of the support. The apparatus also includes a displacement sensor operable to produce a displacement signal representing a displacement of the operating implement relative to the support. The apparatus further includes a processor circuit operably configured to receive the orientation signal and the displacement signal, use a kinematic model of the loading equipment to compute a spatial positioning of the loading equipment, and produce an output signal representing the spatial positioning.

Abstract: The invention relates to a mining vehicle and method for its energy supply. The mining vehicle has a carriage, driving equipment for moving the carriage, and at least one mining work device. Further, the mining vehicle has at least one electric motor for operating a main function of the mining vehicle, and at least one electric motor for operating an auxiliary function of the mining vehicle. The mining vehicle further has a power-generating auxiliary unit. When necessary, the power-generating auxiliary unit supplies at least part of the power required by the electric motor operating the auxiliary function.

Abstract: The present invention relates to a working device having an element movable via at least one working drive, with at least one energy recovery cylinder being provided for recovering energy from the movement of the movable element and having a chamber filled with gas. In this respect, the energy recovery cylinder has a sealing arrangement for sealing the chamber filled with gas which includes an annular space filled with oil.

Abstract: Systems, methods, devices, and computer readable media for controlling the operation of an industrial machine including one or more components. A method of controlling the industrial machine includes determining a position of at least one of the one or more components of the industrial machine during a digging operation, determining a hoist bail pull setting based on the position of the at least one of the one or more components and a relationship between component position and hoist bail pull, and setting a level of hoist bail pull to the hoist bail pull setting. The level of hoist bail pull early in the digging operation is greater than the level of hoist bail pull later in the digging operation.

Abstract: A work equipment boom is adapted to be attached at one end to a main body of a construction machine and attached at the other end to a work equipment arm. the work equipment boom includes a boom main component. The boom main component is integrally formed by expanding a tubular material. The boom main component has a proximal end portion and a distal end portion. The proximal end portion includes a first end part arranged to be disposed adjacent to the main body and has a shape which increases in horizontal width as it gets nearer to the first end part. The distal end portion includes a second end part arranged to be disposed adjacent to the work equipment arm and has a shape which increases in horizontal width as it gets nearer to the second end part.

Abstract: A construction equipment machine of the loader type is provided and has at least a chassis, a traction arrangement and a loader arrangement. The loader arrangement includes a loader boom structure which is controlled through a two way boom hydraulic cylinder system, and a boom suspension system through which a lift-side of the boom cylinder system may be connected to a hydraulic pressurized accumulator while the drop-side of the boom cylinder system is connected to a tank return line. The tank return line has a flow limiter for limiting the flow of hydraulic oil in the direction from the drop-side of the boom cylinder system to the tank.

Abstract: A hydraulic shovel includes an engine; a hydraulic pump driven by the engine; an excavating attachment which is driven by high oil discharged from the hydraulic pump; a motor generator that assists a power supply of the engine; and an assist control unit that controls the motor generator to assist the engine in a latter part of the excavating operation by the excavating attachment.

Abstract: An electric drive work vehicle is provided having a chassis, at least one power distribution system, and a cabinet that houses the at least one power distribution system. The cabinet may be mounted atop the chassis to shield the cabinet and its contents from ground water and debris.

Abstract: A tractor includes booms, lift cylinders, a hitch, dump cylinders, a magnetic valve, a speed-up circuit, and a speed-up restricting arm. The lift cylinders swing the booms upward and downward by an operating oil being supplied thereto. The hitch is provided to the booms to allow an implement to be attached thereto. The dump cylinders swing the implement upward and downward by the operating oil being supplied thereto. The magnetic valve switches between supplying the operating oil to the dump cylinders and supplying the operating oil to a grab cylinder provided in the implement. The speed-up circuit is able to perform a speed-up operation for increasing the flow rate of the operating oil supplied to the magnetic valve. The speed-up restricting arm is arranged near the speed-up circuit.

Abstract: A sheave includes a hub defining an axis, a rim defining at least one circumferentially extending groove, and two plates oriented substantially perpendicular to the axis. Each plate is connected to the hub and to the rim, and a plurality of reinforcing tubular members extend between the plates.

Abstract: An angle formed on a side of a bucket by a first line segment that connects a first pivot region of a bell crank relative to a boom and a second pivot region of the bell crank relative of a connecting link and a second line segment that connects the first pivot region and third a pivot region of the bell crank relative to a tilt cylinder is no more than 206.5°. An angle formed by the second line segment and a line segment that connects the third pivot region and fourth a pivot region of the tilt cylinder relative to a structural body is, in a fork-attached state, no more than 72.3°. When a pivot region of the fork relative to the boom is substantially 1.5 m from the ground, a lower end of the bell crank is located higher than a lower end of the fork.

Abstract: A hydraulic drive system realizes a jack-up operation without arrangement of a flow rate control valve and center bypass selector valve. The hydraulic drive system has first and second hydraulic pumps, first and second directional control valves for controlling boom cylinders, a third directional control valve for controlling the boom cylinders, and a third hydraulic pump for feeding pressure oil to the third directional control valve. A jack-up selector valve has a second select position where, when a pressure in bottom chambers of the boom cylinders is not higher than a predetermined pressure, feeding of pressure oil, which is delivered from the first hydraulic pump and second hydraulic pump, to rod chambers of the boom cylinders, is held permissible in association with switching of the second directional control valve and third directional control valve by a manipulation of a control device.

Abstract: A travel vibration suppressing device is connected to a hydraulic cylinder for operating a work machine, and utilizes an accumulator to suppress vibration during travel of the vehicle. Upon determining that the state of the work machine is the excavating state, the control unit switches from a state of communication between a hydraulic cylinder and the accumulator to a blocked state when the vehicle speed changes from a speed exceeding a first speed to a speed equal to or less than the first speed. Upon determining that the operating state is the normal state, the state of communication between a boom cylinder and the accumulator is switched to the blocked state when the vehicle speed changes from a second speed lower than the first speed to a speed equal to or less than the second speed.

Abstract: A linear drive mechanism is configured with a vertical column mounted on a mobile base containing a reversible electric motor that is coupled to drive a threaded shaft located centrally within the column. A driving member, engaging the threaded shaft and constrained to vertical travel in a longitudinal slot in a side of the column, can be driven by the motor in a linear path in either direction between the ends of the column. The drive mechanism is adaptable to power a wide variety of auxiliary mechanisms linearly and/or rotationally to perform specific tasks with substantial reductions of manual labor in construction and material-moving tasks including shoveling, picking, hoeing, digging trenches and holes, lifting, e.g. as with a hoist, crane or vertical conveyor, pulling, mixing, e.g. concrete, handling and installing panel workpieces such as drywall, and driving posts.

Abstract: A material extraction system for an underground mine includes an elevated haulage conveyor extending between first and second ends of a roadway entry. The haulage conveyor is cantilevered from a mine wall and conveys material toward either end of the roadway entry. The system also includes a crusher including a drive operable to move the crusher along the roadway entry. The system further includes a bridge conveyor including a first end adjacent the crusher and receiving material from the crusher, and a second end adjacent the elevated haulage conveyor and positioned for depositing material onto the elevated haulage conveyor. The bridge conveyor is moveable with the crusher along the roadway entry. The system also includes a loader moveable along the roadway entry and into and out of material collection entries to collect material therefrom and transport the material to the crusher.

Abstract: A hydraulic drive system for a working machine provides improved safety during forced regeneration. Upon input of a forced regeneration command signal from a forced regeneration switch, a controller detects non-operated states of all hydraulic actuators such as an arm cylinder arranged on a hydraulic excavator based on a lock detection signal from a gate lock detection switch, and also an attitude of a front working mechanism. The attitude is proper from the standpoint of safety. The detection is based on an arm angle signal from an arm angle sensor, a bucket angle signal from a bucket angle sensor and a boom pressure signal from a boom pressure sensor. Taking the detection of the non-operated states and proper attitude as conditions, the controller outputs control signals to a boosting proportional solenoid valve and flow-rate controlling, proportional solenoid valve to make a forced regenerator conduct forced regeneration.