Abstract: Mud and sand are prevented from entering between support-receiving members since both ends of the roller shaft are constructed so as to be held at both sides thereof when providing the upper roller on the travelling body frame secured in a civil engineering apparatus. The first and second support receiving members 19, 20 are constructed so that the members respectively support both end portions of the roller shaft 17a of the upper roller 17 on the upper part of the track frame 11 and cross frame 12 on the travelling body frame 10 secured at the lower part of the civil engineering apparatus, wherein the roller supporting portions 19a, 20b and a pair of coupling pieces 19a, 20a for coupling the roller supporting portions 19b, 20b to the travelling body frame 10 are formed to be substantially reverse U-shaped.

Abstract: A work machine in which a base end section of an arm is pivotally supported by a tip end section of a boom in the front-and-rear direction in an oscillating manner. The work machine includes an arm angle sensor apparatus for detecting an oscillating angle of the arm so that the arm angle sensor apparatus is protected and an increase in cost is suppressed. A sensor body of the arm angle sensor apparatus is attached to a sensor attachment hole provided in the third boom side plate such that the sensor attachment hole includes a part of the sensor body. The link member for transmitting the oscillating angle of the arm to the sensor body is provided between the third boom side plate and the arm side plate such that one end side is connected to the sensor body and the other end side is connected to the arm side plate.

Abstract: An easy manufacturing method of a slip stopper, and apparatus therefor, that has a great slip stopping effect and can be used for a location where a problem occurs if a though hole is opened therein. After a protruding portion is formed on a steel plate, by using a first punching die unit, so as to protrude from the upper surface in a plate thickness direction, a concave portion and drain channels are formed in the protruding portion by shear planes that extend substantially perpendicular to the steel plate upper surface and have been half-blanked so as not to open a through hole in the steel plate by using a second punching die unit.

Abstract: The present invention makes it possible, in an HST drive circuit wherein an HST pump and an HST motor have been separately stored in a pump case and a motor case, to efficiently cool the HST drive circuit. A cooling line for, while discharging a relief oil from a charge circuit 9 for replenishing an HST closed circuit 5 with a pressure oil into a pump case 3, making the discharged oil flow into a reservoir 7 through the pump case 3, a communicating pipe 14, a motor case 4, and an oil cooler 16 is formed, so that hydraulic oil circulating through an HST pump 1, an HST motor 2, and the HST closed circuit 5 is cooled by an oil flowing through the cooling line.

Abstract: A plurality of flexible hoses for supplying hydraulic oil from a main body to a traveling motor of a traveling device and discharging hydraulic oil from the traveling motor to the main body. The hoses between the main body and each traveling device are inserted through a flexible tubular hose cover so as to be contained therein. The plurality of hoses can be bundled and protected merely by being inserted through the hose cover. Even in the bundled state, the hoses are permitted to move inside the hose cover together with a width changing movement of the traveling device. The hose cover including a flexible first material member and a second material member having greater shape retention properities than the first material member.

Abstract: A shutter type guard apparatus composed of a movable guard member which can be opened and closed for covering the window portion of the cab of a piece of machinery. The guard member is structured so that it can be closed to an intermediately opened position where it is easily operated. An auxiliary closing device includes a cable winding device for winding the first cable, a travelling unit coupled between the first cable and a second cable, an auxiliary guide rail in which the travelling unit and the first and second cables are guided for movement, and a pull handle coupled to the second cable. The auxiliary guide member is at one of a pair of left and right guide rails, for guiding the movable guard member. The pull handle is disposed at an intermediate position, in the vertical direction of the guide rail, and by pulling the pull handle downward, the guard member is forcibly closed to an intermediately opened/closed position where it can be easily reached and further closed by hand by an operator.

Abstract: The invention is a fan revolution control method for controlling a pump-motor system, by controlling the fan revolution speed of a cooling fan adapted to be rotated by a fan motor to cool cooling target fluids. The pump-motor system drives the fan motor by a hydraulic fluid fed from a fan pump driven by an engine. The pump-motor system is controlled so the fan revolution speed starts from the minimum fan revolution speed when the engine is started up; the minimum fan revolution speed is maintained for at least several seconds; after the elapse of several seconds, the fan revolution speed is gradually increased from the minimum fan revolution speed. The fan revolution speed reaches a target fan revolution speed over a period of at least several seconds. The method prevents generation of peak pressure or pressure hunting.

Abstract: A driving device of a work machine includes a power generator adapted to be driven by an engine, and a power storage device for storing the electric power generated by the power generator. Electric motors and a motor generator, both adapted to be operated by electric power supplied from either one or both of the power generator and the power storage device respectively drive pumps and a pump motor. Supporting circuits for feeding supporting hydraulic oil are provided between a plurality of driving circuits that drive a plurality of hydraulic actuators of a working unit by oil hydraulics generated by the pumps and the pump motor. By enabling the plurality of driving circuits to effectively share excess energy, the invention makes possible a compact construction of a driving device of a work machine.

Abstract: Actual temperatures of intake air, hydraulic oil, and coolant, to be cooled by a cooling fan, are detected. Target fan revolution speeds are determined by PI control units based on differences between the actual temperatures and target temperatures. The cooling fan is controlled based on the target fan revolution speeds. To restrict accumulation of negative integral elements when performing integration by the PI control units an integration start control system adapted to control the timing for each PI control unit to initiate integration is provided. Target temperatures for initiating integration are respectively set, and control is performed so that integral elements of each PI control unit are kept invalid until the actual temperature of the corresponding cooling target fluid, i.e. the intake air, the hydraulic oil, or the coolant, reaches the corresponding target temperature. Delay in rise of fan revolution speed is prevented.

Abstract: A latch body is mounted on the lower portion of a seat platform of a driver seat. An engaging portion is mounted on the upper portion of a seat frame. When an opening on the top of the seat frame is covered by the seat platform, the latch body engages the engaging portion. The seat frame may be opened and closed to enable inspection of an engine through a top opening by pivoting the seat platform. The seat platform does not vibrate relative to the seat frame due to impacts incurred while traveling. And is not moved by the posture of the operator who performs tasks while sitting on the seat platform. The stability of the seat platform is ensured.

Abstract: The invention provides an air-conditioning apparatus that maximizes the space in an operator's cab and provides a comfortable working environment for the operator of a construction machine. The body unit of the air-conditioning apparatus is disposed under the floor surface of the cab, cold air and hot air ducts are connected to the body unit, and routed under the floor of the cab to be passed through the floor surface and taken out into the inside of the cab using cold air and hot air outlets disposed at both left and right sides at the front part of the cab. Also, by providing two evaporators, air of different temperatures can be blown through the left and right outlets.

Abstract: The air conditioner capacitor is arranged at the front side of the oil cooler or the radiator against the flow of the cooling air, thereby carrying out maintenance of the oil cooler and/or the radiator at the rear side without removing the air conditioner capacitor arranged at the front side, thus improving maintenance. The turbocharger cooler 11 is structured to change the postures so as to swing up and down between the cooling posture in which the turbocharger cooler 11 is arranged in parallel with the radiator 8 and an open posture in which the turbocharger cooler 11 is arranged such that the front side of the radiator 8 is exposed.

Abstract: A hydraulic system, particularly suitable for use in a work machine, is provided with a hydraulic pressure source. A first hydraulic load is associated with a first load function. A second hydraulic load is associated with a second load function. An independent metering valve assembly includes a plurality of independently and electronically controllable valves. The independent metering valve assembly includes an inlet fluidly coupled with the pressure source, a first outlet fluidly coupled with the first hydraulic load, and a second outlet fluidly coupled with the second hydraulic load. The hydraulic system is configured such that the independent metering valve assembly may operate and drive multiple hydraulic load functions.

Abstract: The back face of a main blade body includes mounting parts, with a box structure having a mounting hole opened in the width direction and a cross section intersecting the width direction is non-circular. At the back face of each width expansion blade body is a fitting part, removably inserted into the mounting hole. A latching member latches the fitting part fitted in the mounting hole. For width expansion, the fitting part is fitted from the outer end side of the mounting hole to position the width expansion blade body at an end of the main blade body. For the housing, the fitting part is fitted from the inside of the mounting hole to house and position the width expansion blade body at the back face of the main blade body. In the width-expanded state, loads are received by the corresponding mounting part to lighten the burden placed on the latching member.

Abstract: The present invention relates to a construction machine in which a superstructure is rotatably mounted on an undercarriage, and is made up of an undercarriage (101) having a hollow frame (104), a superstructure (102) mounted on the undercarriage (101) and a fuel tank (1) formed as one with the hollow frame (104) in a state where a portion of an internal space of the hollow frame (104) is defined as a compartment by partitions (2), with an internal surface of the fuel tank (1) being covered with a resin film (3) in a liquid-tight condition.

Abstract: In a cooling package for a construction machine, where a cooler (16) from among coolers (15, 16) is disposed separately from an engine (10) and the separately provided cooler (16) includes a screen (19), a lid (30, 50) for covering the screen (19) from above is provided on an upper face of the construction machine independently of a side door (21A, 21B) provided on a side face of the construction machine for covering the cooler (15, 16) from forwardly and an engine hood (22) provided on the upper face of the construction machine for covering the engine (10) and the cooler (15) provided for the engine (10) from above so that, even when the location forwardly of the cooler (16) disposed separately from the engine (10) is occupied by some other apparatus, the screen (19) can be removed or mounted without being disturbed by the apparatus.

Abstract: To perform boom-down operation by operating a boom cylinder (6) by an external load (W) while simultaneously operating an arm cylinder (26) or a bucket cylinder (27) in the state the bucket is off the ground, a first boom directional control valve (2) and a regeneration boom valve (13) are controlled to the neutral position and the open position respectively so that the hydraulic oil is regenerated from a line (9) located at the oil-returning side of the boom cylinder (6) through the regeneration boom valve (13) to a line (5) located at the oil-feeding side. Therefore, the volume of the hydraulic oil that can be supplied from the pressurized oil source (4) to the arm cylinder (26) or the bucket cylinder (27) via the second arm directional control valve (24) or the bucket directional control valve (25) is increased by the amount equivalent to the amount of the oil that is not supplied from the pressurized oil source (4) to the boom cylinder (6).

Abstract: A fluid control system may include a pump, a tank, and an actuator. A valve assembly may be configured to control fluid communication between the actuator, the tank, and the pump. An energy recovery circuit, including a pressure transformer, may be fluidly coupled to the actuator in parallel with the valve assembly.

Abstract: A hydraulic control circuit for a boom cylinder in a work machine, which, when controlling supply and discharge of pressurized oil with respect to a boom cylinder, improves fuel efficiency, work efficiency in combined operations, and improves work efficiency and operationality in the work of difficult boom operations, such as debris raking-up work and bumping work, wherein the hydraulic control circuit of a boom cylinder is provided with a change valve to hold a first boom control valve at a neutral position, a communication line for causing a head side oil chamber and a rod side oil chamber to communicate with each other, an opening valve for opening and closing the corresponding communication line, and pilot operating check valve that is changed to an unidirectional state where, although an oil flow from the head side oil chamber to the rod side oil chamber is permitted, a reverse flow is hindered, and to a bi-directional state where oil flows in both directions, and further a second boom control valve is p

Abstract: A hydraulic control circuit of a boom cylinder for a work machine, which, when controlling the supply and discharge of pressurized oil with respect to a boom cylinder, improves fuel efficiency, work efficiency in combined operations, and work efficiency and operationality in work of difficult boom operations, such as debris raking-up work and bumping work, etc. The hydraulic control circuit of a boom cylinder is provided with a first change valve for holding the boom control valve in the neutral position, a communication line for causing the head side oil chamber and the rod side oil chamber to communicate with each other, an opening and closing valve for opening and closing the communication line, and a pilot operation check valve that is changed to an unidirectional state where, although an oil flow from the head side oil chamber to the rod side oil chamber is permitted, a reverse flow is hindered, and a bi-directional state is permitted where the oil flows in both directions.