摘要:
An object of the present invention is to provide a computer power supply in which, by improving the circuit itself, internal heat loss can be reduced, thereby greatly improving efficiency. A partial resonance circuit 8 is constituted by a primary side winding N1 of a high frequency transformer 3, a resonance condenser 7, and two switching elements Q1, Q2, a secondary side output circuit 4 for driving a load is connected to a secondary side of the high frequency transformer 3 via a winding, and a reverse converter 11 for driving and halting the first switching element and second switching element by causing the respective phases thereof to differ on the basis of a driving signal is provided.
摘要:
A magnetic head mounting device of a magnetic recording apparatus including a carriage, a first magnetic head supported by the carriage, a head arm supported by the carriage for movement in a vertical direction, and a second magnetic head supported by the head arm and disposed in spaced juxtaposed relation to the first magnetic head, wherein both or one of the first magnetic head and second magnetic head is mounted on the carriage or head arm through a gimbal. The gimbal includes a head mounting section for mounting the first magnetic head or second magnetic head thereto, and a supported section disposed outwardly of the head mounting section and partly supported by projections located at the carriage or head arm, the head mounting section and supported section being partly connected together through a plurality of connections. The gimbal is mounted to one or both of the head arm and carriage in such a manner that the head mounting section and supported section are connected together in a direction which is parallel to the direction of sliding movement of the carriage.
摘要:
The current operational condition is discriminated as being the vehicle propulsion condition or the performing work condition. When the vehicle propulsion operational condition is discriminated, the maximum engine revolution speed is limited to a first revolution speed and the maximum displacement is limited to a first displacement value. When the performing work condition is discriminated, the maximum engine revolution speed is limited to a second revolution speed equal to or lower than the first revolution speed and the maximum displacement is limited to a second displacement value higher than the first displacement value. The first and second revolution speeds and the first and second displacement values are so determined that the first revolution speed multiplied by the first displacement value at least as relating to pressure for vehicle propulsion on level ground is less than the second revolution speed multiplied by the second displacement value as relating to the pressure for below the range of torque limitation control. By this, the pump output flow during vehicle propulsion on level ground is made lower than while performing work and, during vehicle propulsion, reduction of the pressure loss is made possible. Even with the identical pump pressure, the effective motor pressure is increased, so that its output torque can be increased. Because also the maximum displacement of the motor can be reduced according to the reduction of the maximum pump output flow amount, the construction of the hydraulic circuit can be made more compact.
摘要:
The displacement of a variable displacement hydraulic pump (1) which is driven by a diesel engine (27) is so controlled as to be set to a first target displacement to keep a pump pressure higher than a load pressure by a predetermined target value, or a second target displacement to limit an input torque on the basis of the pump pressure. Provided is a stand-by flow rate control portion (65) which outputs a third target displacement larger than the minimum value of said first target displacement. The displacement of the pump (1) is controlled so as to be set to the third target displacement when the third target displacement is output from the stand-by flow rate control portion (65).
摘要:
An engine revolution speed control device according to the present invention comprises: a hydraulic pump (1) which is driven by an engine (21); a hydraulic motor (4) for vehicle movement which is driven by oil expelled from the hydraulic pump (1) during vehicle movement; an actuator (52) for working which is driven by the oil expelled from the hydraulic pump (1) during the working state; a vehicle driving pedal (6) which during vehicle movement controls vehicle speed according to its amount of operation; a means (33) for speed reduction decision which makes a decision as to whether the amount by which the vehicle driving pedal (6) is depressed is being reduced; and a means for revolution speed control (33). The means for revolution speed control (33) performs normal control by increasing or decreasing the revolution speed of the engine according to the amount by which the vehicle driving pedal (6) is depressed, and, when it is decided that the amount by which the vehicle driving pedal (6) is depressed is decreasing, performs controlled slowing down by reducing the revolution speed of the engine while delaying its reduction amount. And, when during working the engine revolution speed is being adjusted by the use of the vehicle driving pedal (6), controlled slowing down is prevented even when the amount by which the vehicle driving pedal (6) is depressed is decreasing.
摘要:
A control system of hydraulic construction machinery includes a prime mover, at least one variable displacement pump driven by the prime mover, at least one actuator hydraulically driven by the pump, maximum revolution number altering device for the prime mover, maximum displacment volume altering device for the pump and an information provider device for providing information on the operation mode of the actuator, whereby the maximum revolution number altering means and maximum displacement volume altering means are controlled by the information provider device to provide a maximum number of revolutions and a maximum displacement volume which suit the operation mode indicated by the output signal. A product of the maximum displacement volume and the number of revolutions becomes at a constant always at the same time when the maximum displacement volume of the pump is varied in response to an output signal of the information provider device, whereby a change in the quantity of pumped fluid can be avoided when the maximum displacement volume of the pump is altered.
摘要:
The present invention relates to an illuminated umbrella intended to assure safety of the user of the umbrella in rainy weather, comprising a light source in a handle or a shaft, thereby illuminating at least part of the shaft coupled to the handle, and therefore the inside of the umbrella, and the face of the user or the vicinity are illuminated by illuminating the shaft itself which is near the face when using to notice the presence of man emphatically to others and drivers, so that the safety of the user in traffic may be enhanced.
摘要:
The invention relates to a vehicle with hull having a hull serving as a roof when mounted on a car detachably fixed on the upper part of a car body, and by detachably mounting and fixing the hull with the ship's bottom directed upward on the upper part of the car body of the vehicle from which the roof is removed, particular carriage is not needed when transporting the hull, and the Overall length is not extended when transporting the hull, and moreover the hull can be used as the roof when mounted on the car, and when dismounted,it can be used as the hull itself.
摘要:
When the pump pressure detected through a pressure detecting line 48 is raised higher than a first predetermined pressure Pd1, a recovery switching valve 44 is shifted to a valve-closed position to cease the recovery function. At this time, the pump delivery pressure detected through a pressure detecting line 51 is higher than a second predetermined pressure Pd1* close to the first predetermined pressure Pd1, and an engine speed increasing device 52 controls an engine controller 11 to increase the rotational speed of an engine 10, thereby increasing the pump delivery rate. Thus, it is possible to make small speed change of an actuator and to increase working efficiency with no deterioration in operability, even when a recovery function is ceased.
摘要:
A hydraulic drive system for a construction machine comprising a prime mover (1), a hydraulic pump (2) of variable displacement type driven by the prime mover, at least one hydraulic actuator (6) driven by a hydraulic fluid delivered from the hydraulic pump, control valves connected between the hydraulic pump and the actuator for controlling a flow rate of the hydraulic fluid supplied to the actuator dependent on the operation amount of control apparatus, pump control apparatus for controlling a displacement volume of the hydraulic pump dependent on the operation amount of the control apparatus such that the delivery rate of the hydraulic pump is increased with an increase in the operation amount, and prime mover control apparatus (29) for controlling a revolution speed of the prime mover. The prime mover control apparatus (29) has a function (33, 36) to monitor saturation of the delivery rate of the hydraulic pump (2), and to raise up the revolution speed of the prime mover (1) to prevent the pump from the saturation when the hydraulic pump reaches a predetermined state concerned with the saturation.