Abstract:
A hybrid compressor selectively driven by an engine and an electric motor. The hybrid compressor includes a variable displacement compression mechanism. When the compression mechanism is driven by the motor, the cooling capacity of a refrigeration circuit that includes the hybrid compressor is adjusted by controlling the inclination of the swash plate and the motor speed. In the control procedure, the inclination angle of the swash plate and the motor speed are controlled so that the compression mechanism and the motor are most efficiently operated to achieve the required cooling capacity. Therefore, the hybrid compressor is constantly operated with maximum efficiency.
Abstract:
A control device is herein disclosed which comprises a drive piston 12p for changing the position of a slanting plate in a variable capacity pump 11, an electromagnetic proportional valve 13 for driving the drive piston, and a position detector 14 for detecting a position of the slanting plate. The control device performs a flow rate control of operating oil by controlling the electromagnetic proportional valve in accordance with a difference between a flow rate instruction value Fr for the operating oil and a position detection value from the position detector so as to change the position of the slanting plate. The control device further includes a pressure detector 18 for detecting a pressure of the operating oil supplied to an injection cylinder 10, and correcting means for correcting the flow rate instruction value on the basis of a pressure detection value from the pressure detector to output a corrected flow rate instruction value.
Abstract:
A load sensing control system for a hydraulic machine sets a variable target differential pressure between a delivery pump pressure and a load pressure of an actuator. A control factor is determined that becomes larger as the deviation between the target differential pressure and the actual differential pressure is increased, and that becomes smaller as the differential pressure deviation is decreased. The control factor also becomes larger as the target differential pressure becomes smaller. The target displacement volume for the hydraulic pump is based on the differential pressure deviation, which is calculated from the target differential pressure and the control factor.
Abstract:
A displacement detection device for a variable displacement compressor in which a swash plate which is connected to a piston through shoes in a housing slides relative to the shoes and rotates synchronously with a drive shaft with a wobbling motion in an axial direction of the drive shaft as the drive shaft is rotated, and an inclination angle of the swash plate is controlled thereby changing a stroke of the piston, includes a detection object provided in a first portion of an outer periphery of the swash plate where an imaginary plane passing through a point of intersection between a line connecting top and bottom dead center positions of the swash plate and an axial line of the drive shaft in perpendicular relation to the line intersects with the outer periphery of the swash plate and a detector provided in the housing so as to face the detection object.
Abstract:
A hydraulic drive unit of a press machine and a swash plate type variable capacity axial piston pump to use for a hydraulic drive unit. Discharge of the pump and the direction of the hydraulic pressure can be controlled at high speed, and the direction of the hydraulic pressure and the timing of the discharge can coincide. The selector device 12 that includes spool valves in parallel is used in place of a servo valve. An electric motor 30 for driving the pump and cam of the axial piston pump 11 and an electric motor 47 for driving the selector cam of the selector device 12 are controlled cooperatively by commands from the numerical control device 14. Two spools 44a, 44b of the selector device 12 perform changeover actuation alternately. Synchronous control of the discharge of the axial piston pump 11 and the flowing direction change of working fluid to the hydraulic pressure cylinder 1 are done, so that the piston 1a of the hydraulic pressure cylinder 1 is made to move up and down.
Abstract:
A variable capacity wobble plate compressor of the type that a wobble plate mounted on a drive shaft is swung axially of the drive shaft as the drive shaft rotates, and pistons connected to the wobble plate make reciprocating motions in response to swinging of the wobble plate, wherein a change in the angularity of the wobble plate causes a change in stroke of the reciprocating motions of the pistons whereby the capacity of the compressor is varied. A sensing element arranged on the wobble plate is moved along a predetermined orbital path together with swinging of the wobble plate. A sensor arranged on a compressor housing generates an electric signal when the sensing element passes by the sensor as the wobble plate swings. A control unit determines the rotational speed of the compressor and the angularity of the wobble plate on the basis of the electric signal from the sensor. The sensor is so located as to align with a predetermined location between an axial center of the predetermined orbital path of swinging of the sensing element and an extreme possible point toward the pistons, when the wobble plate assumes the minimum angularity.
Abstract:
Disclosed is a device for controlling or measuring operational parameters of an axial piston machine. The tilting plate which engages and adjusts the stroke of the piston is provided with two opposite pivot pins supported in fixed bearings. At least one pivot pin is provided with a shearing stress sensor preferably in the form of a magnetoelastic feeler which produces electrical signals the pulsation of which is indicative of rotational speed and the magnitude of the signal is proportional to pressure applied by the pistons and thus to the delivery of the machine. A second sensor is coupled to the tilting plate to indicate the angular displacement of the latter. The output signals from the sensors are separated into the pressure dependent signals, frequency dependent signals and angular displacement signals which upon multiplication are applied to a programmable data processing unit. The output of the unit is supplied to a solenoid operated proportional valve which controls pressure fluid for hydraulic setting motors which adjust the angular displacement of the tilting plate.
Abstract:
Control system and control method of a variable displacement hydraulic pump wherein the system includes a detection sensor for detection of the actually set displacement and a control unit for current control of a couple of solenoids controlling displacement increase and decrease.
Abstract:
A method for controlling an electrical drive of an electrically driven air compressor of a motor vehicle and a corresponding control circuit. A prevailing load torque of the air compressor that is applied at a drive shaft of the compressed air compressor is estimated as a function of at least one operating parameter and is fed forward as an estimated disturbance variable to the control circuit of the electrical drive to reduce a control error produced as a result of the prevailing load torque.
Abstract:
Disclosed is a supplying device of fixed colorants volume for a colorant dispenser. The supply device includes: a colorant source; a cylinder body having multiple piston cylinders arranged around a circumferential direction thereof; a swashplate having an oblique surface and arranged substantially coaxially with the cylinder body; multiple piston mechanisms, where each piston mechanism includes a piston rod and a piston connected to the piston rod, the piston rod has a rolling abutment structure abutting against the oblique surface, and the piston is constructed to be capable of making a stroke movement in the corresponding piston cylinder by means of rotation of the swashplate; an actuator for actuating the swashplate; a controller operatively connected to the actuator to control the amount of rotation of the swashplate; and an outlet for dispensing a colorant. Preferably, the supply device further includes an axial reset mechanism and a circumferential reset mechanism.