Abstract: A machine diagnosing system is provided which can make an abnormality/failure diagnosis of a machine without using threshold values. It is composed of a dynamic state management controller that creates frequency distribution information showing a relationship between signal intensity related to engine output and occurrence frequency whenever the machine body is operated for a predetermined time, a management section that receives and stores pieces of frequency distribution information, and terminal equipment and each of which detects a decrease in engine output by arranging the pieces of frequency distribution information obtained from the management section in time series and by comparing these pieces of information with each other.

Abstract: A method and apparatus that detects a multiplicity of normal data sets, each of which includes values of n parameters, for each of the operation modes of an object having a plurality of operation modes. Self-organizing maps are provided for each operation mode using the normal data sets. Abnormal data sets representing virtual abnormal states are created by modifying the values of the n parameters of each of the multiple normal data sets so that as many abnormal data sets as the number of deviation vectors are created for each of the multiple normal data sets. Abnormal operation mode proportion vectors are then created by selecting a self-organizing map from the above noted self-organizing maps which has the highest similarity degree to each of the abnormal data sets.

Abstract: Provided is a starter motor control circuit capable of easily preventing the induction of a short-circuit current due to a ground fault in the power source line of a starter motor, in which a high current flows. A key switch (13) is connected with a battery (11), and a starter motor starting signal line (19) of a starter motor (18) is connected through a starter relay (16) with a start (ST) of the key switch (13). A protect relay (22) is disposed in a battery line (21) between the battery (11) and the starter motor (18). A ground fault detecting line (24) for detecting the ground fault of the battery line (21) is disposed between the battery line (21) and a controller (14). The controller (14) has a function to restrict the connecting actions of the starter relay (16) and the protect relay (22) when the ground fault of the battery line 21 is detected by a ground fault line (24), even if the key switch (13) is changed to the start (ST).

Abstract: A hydraulic system for a machine is disclosed. The hydraulic system has a source of pressurized fluid and a fluid actuator with a first chamber. The hydraulic system also has a first valve configured to selectively fluidly communicate the source with the first chamber. The first valve further includes a first element movable between a flow passing, at which fluid from the source flows to the first chamber, and a flow blocking position, at which fluid from the source is blocked from the first chamber and a second element configured to selectively drain a control passageway associated with the first element to cause the first element to move. The hydraulic system further has a proportional pressure compensating valve configured to control a pressure of a fluid directed between the source and the first valve dependent upon the pressure of the control passageway.

Abstract: A panel that realizes satisfactory strength, weight reduction and acoustic performance. Panel (17,18) has cavity (22) defined by inside thin sheet (23) fixed to the inside surface of outside thin sheet (21), and the cavity (22) is filled with foam (24). Preferably, the foam (24) consists of a rubber acoustic material of high expansion. For the inside thin sheet (23), not only circumferential edge portion (26) and circumferential side portion (25) for defining the cavity (22) but also recessed portion (27) for increasing the panel strength is draw formed on the side of outside thin sheet (21). The bottom surfaces of the circumferential edge portion (26) and recessed portion (27) of the inside thin sheet (23) are bonded to the outside thin sheet (21) by a thermosetting adhesive.

Abstract: In a work machine equipped with a switchover means enabling selective operation of traveling devices and a work device by means of common operating levers, switchover can easily be performed and also easily recognized. In a work machine having traveling devices and a work device, operating levers that are capable of operating the traveling devices and the work device are respectively disposed at the sides of an operating seat. A foot switch connected to a controller is disposed in the proximity of and operable with a foot of an operator seated at the operating seat. While the foot switch is being operated with the foot, the traveling devices are operated by the operating levers through the controller. While the foot switch is not being operated, the work device is operated by means of the operating levers through the controller.

Abstract: Boom operating valves, a stick operating valve, etc. for respectively controlling hydraulic fluid fed from hydraulic pumps to boom cylinders, a stick cylinder, and other actuators are provided with center by-pass lines Cb. A stick-in meter-out load pressure compensating valve is provided on a rod-side return line, which extends from a rod side of the stick cylinder to a tank. A pressure sensor is provided at the rod side of the stick cylinder so as to detect pressure of hydraulic fluid fed to the rod side. The center by-pass line Cb associated with the stick operating valve is provided with an electromagnetic relief valve for controlling the pressure in the portion of the center bypass line downstream from the stick operating valve so as to increase the pressure in accordance with.

Abstract: A hydraulic circuit that enables smooth absorption of the energy of a return fluid from a hydraulic actuator by means of an energy recovery motor. A return fluid passage to which the fluid discharged from a boom cylinder is branched is provided at the tank passage side of a solenoid valve of a boom control circuit. The return fluid passage comprises two return passages, which are provided with a flow rate ratio control valve for controlling a ratio of fluid that branches off into the return passages. The flow rate ratio control valve is comprised of a solenoid valve disposed in the return passage, which is provided with an energy recovery motor, and a solenoid valve disposed in the return passage, which branches off the upstream side of the solenoid valve.

Abstract: A hydraulic system is disclosed having a source of pressurized fluid, at least a one hydraulic actuator, and a first valve. The first valve has a first valve element movable relative to a first valve bore between a plurality of positions from a first position in which pressurized fluid is substantially blocked from flowing toward the at least one hydraulic actuator to a second position in which pressurized fluid is allowed to flow toward the at least one hydraulic actuator. The first valve element is configured to be selectively moved from a third position located between the first and second positions to a fourth position located between the third and second positions at least partially based on a pressure signal of pressurized fluid downstream of the first valve.

Abstract: This disclosure relates to a hydraulic system and method that converts the kinetic energy generated by the operation of a swing motor into hydraulic potential energy and reuses the hydraulic potential energy for swing motor acceleration. An accumulator can be provided for storing exit oil from the swing motor that is pressurized by the inertia torque applied on the moving motor via movement of an upper structure of a machine. The pressurized oil in the accumulator can be reused to accelerate the swing motor by supplying pressurized oil to the swing motor.

Abstract: A hydraulic control system for a machine is disclosed. The hydraulic control system may have a first fluid actuator, a first pump configured to produce a first stream of pressurized fluid, a second fluid actuator, and a second pump configured to produce a second stream of pressurized fluid. The hydraulic control system may further have a combiner valve, and a controller. The controller may be configured to receive an operator input indicative of a desired velocity for the first fluid actuator, determine a flow rate for the first fluid actuator corresponding to the desired velocity, and determine a flow capacity of the first pump. The controller may also be configured to move the combiner valve to combine the second stream of pressurized fluid with the first stream of pressurized fluid when the determined flow rate for the first fluid actuator is greater than the determined flow capacity of the first pump.

Abstract: A fluid pressure circuit that can, in either case where a first actuator that is fed from a first pump or a second actuator that is fed from a second pump is operated, by allowing feeding of the hydraulic fluid to a specific actuator from either the first or second pump, improve interlockability with the specific actuator. A control valve is incorporated with a plurality of first-group spools fed from a drive pump and a plurality of second-group spools fed from an idle pump. A solenoid selector valve unit switches a pilot line of a second-group tool controlling spool to a communicating state at the time of detection of a spool operation by a first pressure switch and switches a pilot line of a first-group tool controlling spool to a communicating state at the time of detection of a spool operation by a second pressure switch.

Abstract: A valve control unit that prevents a decline in interlocking operation performance when pilot pressure control of a plurality of pilot-operated control valves is carried out by proportional solenoid valves. First and second proportional solenoid valves include a Common Operation Table of lever operation amount/boom-up pilot pressure characteristics and are inputted with a common boom-up lever operation amount. A third proportional solenoid valve also includes the Operation Table and is inputted with a stick-in lever operation amount common to the fourth proportional solenoid valve. The fourth proportional solenoid valve includes an Operation Table of lever operation amount/stick-in pilot pressure characteristics different from that of the first, second, and third proportional solenoid valves and is inputted with the stick-in lever operation amount common to the third proportional solenoid valve.

Abstract: A boom control circuit for controlling hydraulic fluid fed to a boom cylinder is provided separately and independently from a travel/stick/bucket control circuit, which serves to control hydraulic fluid fed to travel motors, a stick cylinder, and a bucket cylinder. The boom control circuit includes a boom pump, an energy recovery motor disposed in a return passage through which return fluid from the boom cylinder 8bmc passes, and a boom motor generator connected to the energy recovery motor. The aforementioned boom pump is connected through a clutch to the boom motor generator. The invention is capable of providing a work machine of which a boom control circuit is adapted to function independently so that the flow rate required by the boom control circuit can be easily ensured.

Abstract: To provide a work machine in which traveling devices and an implement device can be operated by common operating levers, wherein switching operation is easy and a changeover is easily confirmed. Inside a cab of the work machine, there are provided travel pedals, with which the traveling devices can be operated, and operating levers, with which the traveling devices and the implement device can be operated. A changeover switch is provided on a console positioned in the vicinity of one side of an operating sheet. The changeover switch switches over between a traveling mode, in which traveling operation is possible by the operating levers, and a work mode, in which implement operation is possible by the operating levers.

Abstract: A work machine enabling a hybrid drive system to be directly driven by energy contained in a return fluid discharged from a hydraulic actuator. The work machine includes a hydraulic actuator control circuit and a swing control circuit. The hydraulic actuator control circuit serves to control hydraulic fluid supplied from pumps of a hybrid drive system to travel motors and work actuators. The swing control circuit serves to control a swing motor generator, which functions as an electric motor and, during braking of rotating motion of the upper structure, functions as a generator. The hydraulic actuator control circuit includes an energy recovery motor provided in a return passage, through which return fluid recovered from a work actuator flows. The energy recovery motor is adapted to be driven by return fluid and thereby drive a motor generator of the hybrid drive system.

Abstract: A swing control circuit is provided separately from a hydraulic actuator control circuit. The swing control circuit includes a swing pump motor connected to closed circuits of a swing motor through a solenoid valve that serves as a directional control valve. A swing motor generator is connected to the swing pump motor. The swing motor generator is connected to an electric power storage device of a hybrid type drive system. An exterior-connecting passage for feeding hydraulic fluid to hydraulic actuators of a lower structure and a work equipment is drawn from a pipeline between the swing pump motor and the solenoid valve. A connecting passage solenoid valve is disposed in the exterior-connecting passage. The invention enables hydraulic energy generated in the swing system to be directly fed to the outside of the swing system.

Abstract: The invention provides a swing drive device that is capable of energy conservation by limiting loss of hydraulic fluid pressure energy resulting from discharge of the hydraulic fluid pressure energy as thermal energy into the air during acceleration or deceleration of swinging action and transforming motion energy to electric energy during deceleration of swinging action, and also enables cost reduction by making components and parts compact.

Abstract: A hydraulic system for a work machine is provided. The hydraulic regeneration system has a tank, a primary source, a first actuator, an accumulator, and a first valve mechanism. The tank is configured to hold a supply of fluid. The primary source is configured to pressurize the fluid and has a suction inlet and a discharge outlet. The first actuator is configured to receive pressurized fluid from the discharge outlet of the primary source. The accumulator is in fluid communication with the tank, the suction inlet of the primary source, and the first actuator. The first valve mechanism is disposed between the suction inlet of the primary source and the accumulator, and is movable between a first position at which fluid returning from the first actuator is directed to the suction inlet of the primary source, and a second position at which fluid returning from the first actuator is directed to only the accumulator.

Abstract: A control system for a work machine having a plurality of removably attachable work tools is disclosed. The control system has a tool recognition device configured to generate a recognition signal corresponding to each of the removably attachable work tools, and at least one fluid actuator configured to move at least one of the plurality of removably attachable work tools. The control system also has at least one fluid sensor configured to generate a load signal and at least one operator interface device configured to generate a desired velocity signal. The control system further has a controller in communication with the tool recognition device, the at least one fluid actuator, the at least one fluid sensor, and the at least one input device. The controller is configured to command a velocity for the fluid actuator in response to the recognition signal, the load signal, and the desired velocity signal.