摘要:
A controller 24 includes function generators 151, 152. The function generator 151 is set to have such a characteristic that as the detected value P.sub.N of a negative control pressure from a pressure sensor 21 is reduced, a first target tilting amount .theta..sub.N increases from a minimum value to a maximum value, and the function generator 152 is set to have such a characteristic that as the detected value P.sub.B of a control input (pilot pressure) for driving a boom cylinder 6 is increased, a second target tilting amount .theta..sub.B increases from a predetermined minimum value to the same maximum value as the above maximum value. Minimum one of the two target tilting amounts from both the function generators is selected, and a proportional solenoid valve 25 is driven based on the selected minimum tilting amount. This makes it possible to surely suppress an unwanted speed increase of a specific hydraulic actuator other than a boom cylinder, such as a swing motor 9, that would be caused when the tilting amount is controlled based on only the negative control pressure.
摘要:
An engine torque, which corresponds to a target engine speed inputted in a controller, is determined by a functional computing function unit. A torque correction value is added to the engine torque, followed by the multiplication with a constant. The product is divided by a pump delivery pressure to determine a pump displacement. A target tilting corresponding to this value is determined by another functional computing function unit, and is then compared with another target tilting which has been determined from a negative control pressure. The smaller one is selected and is outputted as a target tilting. The torque correction value is set at an EEPROM through an input device as desired. Selection of a negative value as the torque correction value makes it possible to prevent occurrence of stalling.
摘要:
A controller 520 has a data portion 520c in which the relationship between a pump delivery pressure and a target opening area of a variable throttle 300a of a control valve 300 is set such that the target opening area is large when the pump delivery pressure is low, and small when the pump delivery pressure is high. An input portion 520a takes in a detection signal from a pump pressure sensor 700, a processing portion 520b reads the data from the data portion 520c and calculates a signal output to a solenoid proportional valve 590, and an output portion 520d converts the calculated signal into a command signal for the solenoid proportional valve 590 and outputs the command signal. Upon receiving the command signal from the controller 520, the solenoid proportional valve 590 produces a command pilot pressure for the control valve 300 corresponding to the input signal and controls the opening area of the variable throttle 300a.
摘要:
A control system wherein a reverse characteristic having a reverse input/output relationship to a target input/output characteristic of a control object, is preset, and a target value for an output of the control object is calculated. A command signal corresponding to the target value then is determined based on the preset reverse characteristic, and the command signal is output to the control object. The control system includes first means for calculating a command signal corresponding to a given target value for the output of the control object based on the preset reverse characteristic, outputting the command signal to the control object, measuring an output of the control object and estimating a deviation between an actual input/output characteristic of the control object and the target input/output characteristic therefor, and storing data on the deviation between the input/output characteristics as learning correction data. The control system further includes second means for reading out the stored learning correction data and correcting the command signal using the learning correction data.
摘要:
To provide a burglarproof device for a hydraulic machine which has a high degree of security against burglary, ensures high safety, and can be simply installed in a location where the device is hard to find for burglars, a solenoid valve 23 of a burglarproof device 20 is installed in a pilot primary pressure line 3 between a pilot hydraulic pump 1 and a pilot valve device 4. Unless ten numeral keys 21a of a key input device 21 are depressed in the order of the password, an unlocking electronic circuit 22K does not generate an unlock signal and the solenoid valve 23 keeps the pilot primary pressure line 3 cut off. Therefore, a pilot primary pressure from the pilot hydraulic pump 1 is shut off and, even with a manual lever 4c of the pilot valve device 4 operated, no pilot secondary pressure is produced and a main control valve 6 is kept standstill. As a result, a hydraulic cylinder 8 is not operated and the hydraulic machine is unable to move.
摘要:
A multimode mobile telephone apparatus incorporating a transmitter; a receiver; a display unit; a dial input portion; and wireless communication means for a plurality of communication methods to establish communication with a base station, wherein the multimode mobile telephone apparatus is sectioned into single-mode portable terminals 2a and 2b with which communication is established with the base station for each communication method, a transmitter, a receiver, a display unit and a dial input portion of each of the single-mode portable terminals 2a and 2b are integrated into one shared MMI portable terminal 1, and local wireless communication means 43a, 43b, 21 is provided which establishes communication between the single-mode portable terminals 2a or 2b and the MMI portable terminal 1 by a wireless method, and selection and connection with an arbitrary single-mode portable terminals 2a or 2b are performed from the MMI portable terminal 1 through the local wireless communication means 21.