A method for paving wherein the paving operator or a person in the vicinity of the paver remotely controls the flow of paving material from a dump truck into the hopper of the paver.

A control system for construction machinery, includes a hydraulic pump, first and second actuators connected to the hydraulic pump through first and second parallel lines respectively, first and second control valves installed in the first and second parallel lines respectively and configured to control operations of the first and second actuators, first and second spool displacement adjusting valves configured to control displacement amounts of the spools of the first and second control valves, and a controller configured to output a control signal to the first and second spool displacement adjusting valves corresponding to a manipulation signal of an operator, and configured to limit a spool displacement amount of the second control valve according to the manipulation signal for the first actuator when the manipulation signal for a multiple operation of the first and second actuators is received.

In a construction machine with a hydraulic pilot type hydraulic control device, occurrence of jerking is prevented. A hydraulic excavator 1 having hydraulic pumps 51L and 51R, travel motors 22L and 22R, traveling operating levers 34L and 34R, a pilot pump 54, hydraulic pilot valves 55La, 55Lb, 55Ra, and 55Rb, and directional control valves 53L and 53R includes: changeover switches 35L and 35R which change the operating mode of the traveling operating levers 34L and 34R; pilot pressure adjusting devices 5L and 5R which adjust the pilot pressure applied to the directional control valves 53L and 53R; and pilot pressure sensors 56La, 56Lb, 56Ra, and 56Rb. The pilot pressure adjusting devices apply the pilot pressure at the time when the operating mode of the traveling operating levers 34L and 34R is changed to a control mode, to the directional control valves 53L and 53R.

A control system for a dump truck includes a signal reception unit that receives a rising command signal to cause the dump truck including a vessel and a hydraulic cylinder configured to raise and lower the vessel to start a rising action of the vessel, and a vessel control unit that varies an extension speed of the hydraulic cylinder nonlinearly with respect to elapsed time when the signal reception unit receives the rising command signal.

A controller according to the present invention has: a storage section that stores a first relationship between manipulated variables of an operating lever preset for each vehicle-body weight and target delivery pressures of a hydraulic pump; a target delivery pressure computation section that applies the vehicle-body weight inputted through an input device and the manipulated variable of the operating lever corresponding to a pilot pressure detected by pilot pressure sensors, to a first relationship stored in the storage section in order to calculate a target delivery pressure of the hydraulic pump; and a feedback control section that performs feedback control on the center bypass selector valve such that the delivery pressure of the hydraulic pump detected by the delivery pressure sensor agrees with the target delivery pressure of the hydraulic pump calculated by the target delivery pressure computation section.

To enable to arbitrarily change a hydraulic pump which supplies pressure oil to a hydraulic actuator at first in a hydraulic control system equipped with the hydraulic actuator using both first and second hydraulic pumps as a pressure oil source. An operation means is installed which can arbitrarily change working order of the first flow rate control valves for boom and stick for controlling the supply flow rate from first hydraulic pump to boom cylinder and stick cylinder and second flow rate control valves for boom and stick for controlling the supply flow rate from second hydraulic pump to boom cylinder and stick cylinder.

A hydraulic cylinder assembly comprising: a single-acting hydraulic cylinder; an oil tank; a fluid line fluidically connecting the oil tank with the hydraulic cylinder; and a motor unit comprising a pump disposed in the fluid line and comprising a motor configured to operate the pump to pump fluid from the oil tank to the hydraulic cylinder to extend the hydraulic cylinder, and to permit flow of fluid from the hydraulic cylinder to the oil tank through the pump during retraction of the hydraulic cylinder, a pressure sensor configured to output a pressure signal indicative of pressure of hydraulic fluid in the hydraulic cylinder; and a controller configured to control the motor unit based on pressure signals received from the pressure sensor. The hydraulic cylinder assembly is configured so that oil leaving the hydraulic cylinder, during retraction of the hydraulic cylinder, passes through the pump to the oil tank.

An actuating system for a valve which can be used as a control valve. The valve system having an outer housing, a receiving region for a switching spindle of the valve, at least one inductive sensor running in parallel to the receiving region, and at least one substantially circular cylindrical position encorder.

A method for the supply of compressed air of a compressed-air consumer having two fluidically separate, kinematically coupled working areas, wherein each of the working areas is assigned to a valve arrangement which can be independently controlled and can be configured between a blocking position, a first functional position for a fluidically communicating connection to a fluid course and a second functional position for a fluidically communicating connection to a fluid sink and wherein each of the two valve arrangements is configured individually depending on a predefinable movement task for the compressed-air consumer and depending, on at least two pressure values from the following group: supply pressure, first working area pressure, second working area pressure, discharge pressure, for a provision of a predefinable developing for a fluid mass flow or for a provision of a predefinable developing for a fluid pressure in the respective working area or for a provision of a predefinable developing of a valve cross-section.

Universal control circuitry for an electro-hydraulic valve actuator system includes logic gate circuitry to control one or more of a closing solenoid valve, an opening solenoid valve, an emergency shutdown solenoid valve, and a hydraulic fluid pump motor to route hydraulic fluid through a hydraulic circuit to actuate a valve via a hydraulic actuator according to received commands. The universal control circuitry is configured to control operation for multiple different configurations of a hydraulic valve actuator system including double-acting configurations, single-acting spring-to-open configurations, and single-acting spring-to-close configurations, each with or without an emergency shutdown arrangement (which may be configured to trip based on an external shutdown input alone or in combination with a local system power failure), a hydraulic accumulator, and maintained or momentary input commands.