Abstract: A robot system includes a motor provided at a joint, a regenerative resistor that consumes a back electromotive force generated by rotation of the motor as heat, and a controller configured or programmed to predict a life of the regenerative resistor based on a period of time during which the regenerative resistor is consuming heat.

Abstract: A robot system includes: a robot; a portable operation terminal having a teaching function; and a robot controller having operation modes including a teaching mode and another operation mode different from the teaching mode, the teaching mode being an operation mode for teaching a motion to the robot through the portable operation terminal. The robot controller is configured to: detect electrical connection and electrical disconnection between the robot controller and the portable operation terminal; change an operation mode in which to operate the robot to the teaching mode when detecting the connection between the robot controller and the portable operation terminal; and change the operation mode in which to operate the robot to the other operation mode different from the teaching mode when detecting the disconnection between the robot controller and the portable operation terminal.

Abstract: A robot system includes: a robot; a portable operation terminal having a teaching function; and a robot controller having operation modes including a teaching mode and another operation mode different from the teaching mode, the teaching mode being an operation mode for teaching a motion to the robot through the portable operation terminal. The robot controller is configured to: detect electrical connection and electrical disconnection between the robot controller and the portable operation terminal; change an operation mode in which to operate the robot to the teaching mode when detecting the connection between the robot controller and the portable operation terminal; and change the operation mode in which to operate the robot to the other operation mode different from the teaching mode when detecting the disconnection between the robot controller and the portable operation terminal.

Abstract: A diesel engine comprises: a cylinder head covering one end of a cylinder; a piston having a crown surface opposed to the cylinder head, and performing a reciprocating movement within the cylinder; and a fuel injector attached to the cylinder head. The cylinder head is formed with an intake port so as to generate a swirl flow within the cylinder. The crown surface of the piston is formed with a cavity which is recessed toward an opposite side of the cylinder head and which has a circular shape in planar view, and a notch which is recessed radially outward from a peripheral edge of the cavity. The fuel injector is formed with an injection hole oriented toward an inside of the cavity.

Abstract: In a diesel engine, a crown surface of a piston is formed with a cavity which is recessed toward an opposite side of a cylinder head, and which has a circular shape in planar view, and a wall surface forming the cavity includes a lip which is formed on a peripheral edge of the cavity, and which is protruded radially inward, and the lip is formed with a plurality of notches which are recessed radially outward from the peripheral edge of the cavity, and a fuel injector is arranged at a center of the cylinder head, and formed with a plurality of injection holes oriented toward an inside of the cavity so as to radially spray fuel within the cavity, and each of the plurality of the notches is arranged between oriented directions of two adjacent injection holes.

Abstract: The diesel engine is provided with a cylinder, a cylinder head, a fuel injection valve, and a piston. The piston has a cavity, and a notch formed in a circumferential edge of the cavity. The notch includes a first recessed portion which is recessed radially outward from an inner circumferential wall surface of the cavity, and a second recessed portion which is recessed from a crown surface of the piston toward a bottom side of the cavity and continuously extends radially outward from an end, on the crown surface side, of the first recessed portion. A vertical wall, on a downstream side of a swirl flow, of the second recessed portion is formed to extend, in an arched manner, radially inward and toward the downstream side of the swirl flow from a position corresponding to a radially outer side end of the second recessed portion in a plan view.

Abstract: A diesel engine comprises: a cylinder head covering one end of a cylinder; a piston having a crown surface opposed to the cylinder head and reciprocatingly movable in the cylinder; and a fuel injection valve attached to the cylinder head, wherein the crown surface of the piston is formed with a cavity which is concaved toward a side opposite to the cylinder head, and has a round shape in top plan view, and the fuel injection valve is formed with a nozzle hole directed toward the inside of the cavity, and wherein a wall surface defining the cavity has a wall segment formed in a periphery of the cavity at a position deviated from a directional direction of the nozzle hole and protruding toward a radially inward side of the piston in approximately parallel to a plane including a central axis of the piston.

Abstract: A diesel engine includes a cylinder, a cylinder head, a fuel injection valve, and a piston. The piston has a cavity recessed so as to be capable of receiving fuel injected from the fuel injection valve when the piston is positioned at a top dead center, and a notch formed by recessing a part of a circumferential edge of an opening of the cavity radially outward. The notch inclines radially inward at an angle of 0° to 50° relative to a center axis of the cylinder from a piston crown surface toward an inner circumferential wall surface.

Abstract: The diesel engine comprises: a cylinder head covering one end of a cylinder; a piston having a crown surface opposed to the cylinder head and performing a reciprocating movement within the cylinder; and a fuel injector attached to the cylinder head. The crown surface of the piston is formed with a cavity which is concaved toward a side opposite to the cylinder head and has a round shape in top plan view, and a groove concaved from a periphery of the cavity toward a radially outward side of the piston. The groove extends from the lower end on the side opposite to the cylinder head, toward the upper end on the side of the cylinder head, while inclining in a circumferential direction of the piston. The fuel injector is formed with a nozzle hole directed toward the groove.

Abstract: An injector of a diesel engine has a first injection valve and a second injection valve disposed to face each other with respect to the center of a combustion chamber. Assuming that a straight line passing through the first injection valve and the second injection valve is a symmetrical line, one of two regions obtained by dividing a planar region of a combustion chamber (3) into two along the symmetrical line is a first region, and the other of the two regions is a second region, the first injection valve injects fuel toward the first region, and the second injection valve injects fuel toward the second region. A cavity portion is formed in the top surface of a piston. The first injection valve and the second injection valve respectively have injection holes at radially inner positions than the periphery of the cavity portion in plan view.