Patent classifications
F15B13/0422
OFFSET CONTROL STICK SYSTEM AND METHOD
An electric joystick controller is provided that includes a socket, a correlated output device, and a handle. The socket has a base and a shaft defining an axial axis. The correlated output device is coupled to the base of the socket and sends electronic signals to a processor. The electronic signals being correlated to movement of the socket. The handle is offset from the axial axis and forms a gap between the shaft and the handle.
Brake device for vehicle
The brake device for a vehicle generates two master pressures by controlling one single servo pressure to accurately control braking force. The pressure increasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon increasing the servo pressure and the second pressure increasing characteristic obtained from the servo pressure and the second master pressure. The pressure decreasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon decreasing the servo pressure and the second pressure decreasing characteristic obtained from the servo pressure and the second master pressure. Thus, the total braking force of the brake device is the sum of a braking force generated by the first master pressure and a braking force generated by the second master piston.
Work machine
A hydraulic excavator 1 includes an engine 16, a main hydraulic pump 17 driven by the engine 16, a plurality of hydraulic actuators driven with pressure oil discharged from the main hydraulic pump 17, a plurality of flow rate control valves adapted to control the flow rate of pressure oil to be supplied from the main hydraulic pump 17 to the respective hydraulic actuators, a pilot hydraulic pump 18 adapted to supply pressure oil for driving the flow rate control valves, and a controller 15 configured to control the discharge flow rate of the pilot hydraulic pump 18. The controller 15 controls the discharge flow rate of the pilot hydraulic pump 18 such that it becomes equal to the sum of requested pilot flow rates determined in accordance with control commands for the respective flow rate control valves and a preset standby flow rate.
Working machine having a hydraulically operated implement
A working machine including a movable implement, a hydraulic actuator for displacing the implement, and a hydraulic control system for enabling an operator to control movement of the implement. The control system allows the implement to be returned to a desired position or state, such as a return to dig position or a return to float state, in a single automated operation that is initiated by the operator actuating a switch at the same time as moving a joystick in a desired direction. A pilot-operated valve is used to supply hydraulic fluid under pressure to the actuator acting on the implement and the operation of the joystick is detected by means of a pressure sensor connected to a control line of the pilot-operated valve.
Hydraulic system in work machine
A hydraulic system in a work machine includes a travel operation device provided in a pilot oil path between a hydraulic pump a travel pump and including an operation member and configured to generate a pilot pressure supplied via the pilot oil path and an additional pilot pressure in accordance with an operation amount of the operation member. The travel pump is to control a flow direction of hydraulic oil supplied to a travel motor based on the pilot pressure and the additional pilot pressure. A pressure selection valve is provided in a first coupling oil path to select a selected pressure from the pilot pressure and the additional pilot pressure to apply the selected pressure to the pilot hydraulic oil in the second coupling oil path. A pressure adjustment valve is provided in a second coupling oil path to control the selected pressure to be an adjusted pilot pressure.
HYDRAULIC SYSTEM IN WORK MACHINE
A hydraulic system in a work machine includes a travel operation device to generate a pilot pressure and an additional pilot pressure in accordance with an operation amount of the operation member. A travel pump is to control a flow direction of hydraulic oil supplied to a travel motor based on the pilot pressure and the additional pilot pressure. A pressure selection valve is provided in a first coupling oil path to select a selected pressure from the pilot pressure and the additional pilot pressure to apply the selected pressure to the pilot hydraulic oil in a second coupling oil path. A pressure adjustment valve is provided in the second coupling oil path to control the selected pressure to be an adjusted pilot pressure. A differential pressure generation valve is provided in the second coupling oil path to generate differential pressure upstream or downstream relative to the pressure adjustment valve.
Work machine
A work machine includes a flow control valve that controls a flow rate of a hydraulic fluid supplied to a hydraulic actuator, a center bypass line that introduces the hydraulic fluid from a pump through a center bypass passage section of the flow control valve into the tank, a bypass cutoff valve that controls an opening of the center bypass line, a solenoid proportional valve that generates a pilot pressure for controlling the bypass cutoff valve, a pilot valve that generates a pilot pressure for controlling the flow control valve on the basis of an amount of operation of an operation device, and a controller that controls the solenoid proportional valve on the basis of the amount of operation. The controller controls the solenoid proportional valve to reduce an opening area of the bypass cutoff valve according to an increase in the amount of operation in a case the amount of operation is less than a predetermined amount of operation, and controls the solenoid proportional valve to make the opening area of the bypass cutoff valve larger than the minimum opening area in a case the amount of operation is a maximum amount of operation.
Pipeline actuation system
A system using pipeline fluid pressure to provide fluid pressure to an actuator which controls the opening and closing of a pipeline valve, without exhausting pipeline media to the atmosphere.