Abstract: A power source control circuit for a working machine includes an electric circuit connecting a key cylinder, controller and accessories. The electric circuit is provided with a first self-holding relay drivable directly by a relay drive signal outputted from the controller and second self-holding relays drivable in conjunction with the first relay. When a gate lock switch is switched to a lock position while an engine is running, the controller outputs an engine stop signal at a subsequent predetermined timing to stop the running of the engine, and also outputs the relay drive signal to drive the first relay and second relays such that a key-on power supply and an accessory power supply are each held in a cut-off state.

Abstract: An internally threaded hole (17) of a cap nut (15), with which an external thread (6C) of a mounting bolt (6) is threadedly engaged, is formed as a bottomed threaded hole. Its length dimension is set to a dimension (L1) which makes it possible to secure an axial space (18) with respect to a distal end portion (6C1) of the external thread (6C) when the external thread (6C) of the mounting bolt (6) is tightened until a weakened portion (6D) is fractured. When the mounting bolt (6) is fractured at the weakened portion (6D) by an excessive tightening torque, the fractured external thread (6C) on the distal end side can be left in the internally threaded hole (17) in a threadedly engaged state. In consequence, the external thread (6C) of the mounting bolt (6) remaining in the internally threaded hole (17) can be easily loosened by fingertips and removed.

Abstract: An antenna cable break detector used with a construction machine wireless communication apparatus to detect a break in an antenna cable. The antenna cable 4 includes a central wire 6 and an armor wire 7 that is positioned concentrically outside the central wire. One end of the central wire and the armor wire is connected to a communication device. The other end of the central wire is connected to an antenna 3. The other end of the armor wire is grounded. The antenna cable break detector has a direct current shutoff device that is connected to the armor wire to shut off the flow of direct current 15 from the armor wire to the communication device. There is also a current shutoff detection device that is connected to the armor wire to detect the shutoff of the flow of a direct current to the armor wire.

Abstract: A display device for a construction machine has a display switching means, output control means, operation detecting means, and display prohibiting means. The display switching means switches information displayed on a monitor placed in an operation cabin, where the switching is made to prevent display of unnecessary information on the monitor while the construction machine is performing work. The output control means selects display information recorded in information recording means and outputs the selected information to the monitor. The operation detecting means detects whether or not the construction machine is in a working state. When the operation detecting means detects that the construction machine is in the working state, display switching operation of the monitor is performed by the display switching means, and the display prohibiting means prohibits the display of specific information.

Abstract: An antenna cable break detector used with a construction machine wireless communication apparatus to detect a break in an antenna cable. The antenna cable 4 includes a central wire 6 and an armor wire 7 that is positioned concentrically outside the central wire. One end of the central wire and the armor wire is connected to a communication device. The other end of the central wire is connected to an antenna 3. The other end of the armor wire is grounded. The antenna cable break detector has a direct current shutoff device that is connected to the armor wire to shut off the flow of direct current 15 from the armor wire to the communication device. There is also a current shutoff detection device that is connected to the armor wire to detect the shutoff of the flow of a direct current the armor wire.

Abstract: A work machine is provided having a starter motor for starting a prime mover, which without provision of any special hydraulic equipment, allows for draining pressure oil that still remains in a hydraulic actuator for driving a front attachment. The work machine is provided with a boom cylinder for driving a front attachment, a flow rate control valve for controlling a flow of pressure oil to be supplied to the boom cylinder, and a pilot valve for producing an output of a pilot control signal, which serves to switch the flow rate control valve, by using, as a primary pressure, pressure oil delivered from a pilot hydraulic pump driven by an engine. A fuel stop switch is provided for performing stop control on a supply of fuel, which drives the engine, and a switch is provided for maintaining drivable a starter motor, which starts the engine, responsive to the stop control of the supply of fuel to the engine by the fuel stop switch.

Abstract: A monitoring display system for use within a cab of an automotive vehicular construction machine to display on a monitor screen picture images of a dead angle monitor camera as a through-view in the back ground of superimposed picture images of instrumentation data indicating readings of various instruments on the machine.

Abstract: A work machine is provided having a starter motor for starting a prime mover, which without provision of any special hydraulic equipment, allows for draining pressure oil that still remains in a hydraulic actuator for driving a front attachment. The work machine is provided with a boom cylinder for driving a front attachment, a flow rate control valve for controlling a flow of pressure oil to be supplied to the boom cylinder, and a pilot valve for producing an output of a pilot control signal, which serves to switch the flow rate control valve, by using, as a primary pressure, pressure oil delivered from a pilot hydraulic pump driven by an engine. A fuel stop switch is provided for performing stop control on a supply of fuel, which drives the engine, and a switch is provided for maintaining drivable a starter motor, which starts the engine, responsive to the stop control of the supply of fuel to the engine by the fuel stop switch.

Abstract: A display device for a construction machine has a display switching means, output control means, operation detecting means, and display prohibiting means. The display switching means switches information displayed on a monitor placed in an operation cabin, where the switching is made to prevent display of unnecessary information on the monitor while the construction machine is performing work. The output control means selects display information recorded in information recording means and outputs the selected information to the monitor. The operation detecting means detects whether or not the construction machine is in a working state. When the operation detecting means detects that the construction machine is in the working state, display switching operation of the monitor is performed by the display switching means, and the display prohibiting means prohibits the display of specific information.

Abstract: A security system of a construction machine of the present invention has a construction machine, a base station and a communication device. The construction machine comprises a data sending and receiving portion for sending first information, a storage portion for storing received information, and a control portion for controlling an operation of the construction machine. The base station receives the first information from the data sending and receiving portion of the construction machine and sends second information to the construction machine and manages the construction machine. It is configured so that the communication device is connected to the base station through a communication network and can send third information to the construction machine through the base station.

Abstract: A monitoring display system for use within a cab of an automotive vehicular construction machine to display on a monitor screen picture images of a dead angle monitor camera as a through-view in the back ground of superimposed picture images of instrumentation data indicating readings of various instruments on the machine.

Abstract: A security system of a construction machine of the present invention has a construction machine, a base station and a communication device. The construction machine comprises a data sending and receiving portion for sending first information, a storage portion for storing received information, and a control portion for controlling an operation of the construction machine. The base station receives the first information from the data sending and receiving portion of the construction machine and sends second information to the construction machine and manages the construction machine. It is configured so that the communication device is connected to the base station through a communication network and can send third information to the construction machine through the base station.

Abstract: In the arm-crowding or track operation, a calculating portion (700d2 or 700d4) calculates a modification gain (KAC or KTR) depending on an operation pilot pressure and a calculating portion (700g) calculates a decrease modification (DND) based on the KAC or KTR, while a calculating portion (700m or 700p) calculates a modification gain (KACH or KTRH) depending on an operation pilot pressure and calculating portions (700q-700s) calculate an increase modification (DNH) based on the KACH or KTRH. A reference target engine revolution speed NR0 is modified using the DND and DNH. In other operations than the arm-crowding and track operations, NR0 is modified using only the decrease modification (DND) calculated from the modification gain just depending on the operation pilot pressure. In the operation where an engine revolution speed is desired to become higher as an actuator load increases, the engine revolution speed can be controlled in accordance with change of the actuator load as well.

Abstract: A reference pump-delivery-rate calculating portion calculates a reference delivery rate of a hydraulic pump by referring to a table stored in a memory based on a control pilot pressure for the hydraulic pump. A target pump-delivery-rate calculating portion divides the reference delivery rate by a ratio of a maximum revolution speed to a target engine revolution speed, thereby calculating a target delivery rate. A target pump tilting calculating portion divides the target delivery rate by an actual engine revolution speed and a constant, thereby calculating a target tilting. A solenoid output current calculating portion calculates a drive current to provide the target tilting and outputs the drive current to a solenoid control valve. The pump delivery rate is thereby controlled with good response following input change of an operation instructing device.

Abstract: In an ultrasonic inspection and imaging instrument, a pulse generator and a burst wave generator are provided in association with the activation of an ultrasonic probe by the pulse generator and in response to a measurement value obtained from a signal reception circuit portion. A first gate position is obtained with regard to an inspection portion in a sample, and then a second gate position for a burst wave measurement is set by correcting the first gate position. The burst wave measurement is performed by activating the burst wave generator.