87results about How to "Reduce overflow loss" patented technology

A control device for a working machine according to the present invention comprises a capacity variable pump for supplying working oil, a controller for controlling the discharge amount of the pump, a control valve for controlling the working oil discharged from the pump, a hydraulic actuator operated by the working oil from the control valve, an operating lever for operating the hydraulic actuator, and a relief valve to be operated when the pressure of the working oil is a relief pressure or more. The controller has a dynamic emulation model of a hydraulic driving device, and is constituted to estimate the pressure oil flow rate passing through the relief valve from the emulation model according to the operation amount of the operating lever, and to control the pump flow rate of the pump so that the relief flow rate estimation value gets close to zero. According to this, relief loss can be precisely reduced without generating a response delay or pressure loss, and the power can be saved.

An electro-hydraulic control system based on frequency conversion type speed regulation is composed of frequency converter used to change rotation speed of pump, motor hydraulic pump, feedback unit for detection, hydraulic control system, energy regualting unit, and controller. The motor and hydraulic control valve are controlled by frequency converter. The electro-hydraulic control valve, energy regualting unit and frequency converter are controlled by controller. Its advantages are high efficiency, saving energy and high response speed.

The invention discloses a hydraulic energy-saving fuzzy control system for excavators, which comprises a fuzzy controller, a variable displacement pump regulator, a throttle controller, an engine, a pump and a pressure sensor; the fuzzy controller is connected with the variable displacement pump regulator, the variable displacement pump regulator is connected with the pump, the pump is connected with the pressure sensor, the pressure sensor is connected with the fuzzy controller, the fuzzy controller is also connected with the throttle controller, the throttle controller is then connected with the engine, and the engine is then connected with the pump. The hydraulic energy-saving fuzzy control system for excavators increases the energy transfer efficiency of the system, and reduces idle energy consumption inside a hydraulic transmission system.

The invention relates to an energy-saving design method for a variable-load servo control system. According to a hydraulic system designed through the design method, fitting of matched load force is achieved through arbitrary combination of different pressure grades, and throttling losses of a valve port are reduced. Overall management of energy is achieved by means of an energy transmission unit and an energy storage unit. Control is conducted according to the working condition, so that regeneration and recycling of energy are achieved. The transmission efficiency of the system is improved on the premise that the control characteristic is guaranteed.

The invention discloses an electro-hydraulic synchronous uniform loading cutter driving system of a tunneling machine. The electro-hydraulic synchronous uniform loading cutter driving system is characterized in that an ordinary motor is connected with a two-way proportional variable pump; an oil supplementation check valve group, a closed circuit safety valve group, oil openings in the two ends of a flush valve, a reversing valve, a large-drift diameter switching valve and a two-way proportional variable motor are connected in parallel between two oil openings of the two-way proportional variable pump through an isolating switching valve; an oil inlet between two check valves in the oil supplementation check valve group is connected with an oil supplementation system and an oil supplementation pressure limiting valve; an intermediate oil opening of the flush valve is connected with an oil tank through a flush pressure limiting valve; an intermediate oil opening of the reversing valve is connected with an energy accumulator and an electromagnetic proportional overflow valve; the electromagnetic proportional overflow valve and the oil supplementation pressure limiting valve are connected with the oil tank; and the two-way proportional variable motor is connected with a main variable frequency motor and a slave variable frequency motor through a drive system. According to the electro-hydraulic synchronous uniform loading cutter driving system, a motor system and a hydraulic motor system achieve real-time, synchronous and uniform loading drive, the trap escaping ability and adaptability for complex geology of a tunnel tunneling machine are improved, the installing power is decreased, and the energy utilization rate is improved.

The invention provides a constant-power control method for equipment mounted on a pure electric compression type garbage truck. The method comprises performing working mode selection through a state signal of a multi-way valve, if a garbage can rises, a scraper plate performs scraping joining or a slide plate performs rising motion, entering a constant-power working mode; and if other motions are performed, entering a constant-rotating-speed operation mode. In the constant-power working mode, an outlet pressure of a hydraulic pump is detected. If the outlet pressure exceeds a preset pressure of an overflow valve, a motor rotating speed is set to a least allowed rotating speed, and otherwise, a motor target rotating speed is calculated according to a pressure-rotating-speed constant-power relationship. If the calculated rotating speed exceeds a maximal allowed rotating speed, the motor rotating speed is restricted to the maximal allowed rotating speed. If the calculated rotating speed does not exceed the maximal allowed rotating speed, the motor is operated according to the calculated rotating speed. According to the constant-power control method, not only can operation efficiency of the equipment mounted on the pure electric compression type garbage truck be improved, but also overflow loss of the hydraulic pump can be reduced, thereby prolonging duration mileage of an electric vehicle.

The invention relates to an energy-saving hydraulic hybrid power system of a loader and belongs to a power system of the loader. An engine of the hybrid power system is in mechanical connection with a hydraulic variable pump and a hydraulic torque converter; an oil outlet of the hydraulic variable pump is communicated with an oil inlet of a one-way valve; an oil inlet of a second overflow valve and a distribution valve are communicated with oil inlets or oil return ports of the one-way valve, an oil tank, a movable arm oil cylinder, a bucket oil cylinder and a steering oil cylinder respectively; an oil inlet of a hydraulic pump / motor control component is communicated with an oil outlet of a reducing valve; each oil return port is communicated with the oil tank; an oil outlet of a two-position two-way reversing valve is communicated with an oil inlet of the hydraulic pump / motor; the hydraulic pump / motor component and the hydraulic pump / motor are in mechanical connection; and an output shaft of the hydraulic pump / motor is in mechanical connection with the input ends of a front axle and a rear axle through an electromagnetic clutch and a torque coupler. The energy-saving hydraulic hybrid power system has the advantages that: the hydraulic hybrid power system can reclaim the braking kinetic energy of the whole machine, improves the working efficiency and working performance of thewhole machine and has long service life.

A return oil diversion system for a telescopic boom oil cylinder of a high altitude work vehicle comprises a multiple directional control valve, a balanced control valve and the oil cylinder. A port A of the multiple directional control valve is connected with a rodless cavity oil port C1 of the oil cylinder through the balanced control valve. A port B of the multiple directional control valve is connected with a control end K1 of the balanced control valve and a rod cavity oil port C2 of the oil cylinder simultaneously. The rod cavity oil port C2 of the oil cylinder is also connected with the control end K1 of the balanced control valve. A throttling valve and a balanced oil return valve are further connected between the port A and the port B of the multiple directional control valve in series. A control end K2 of the balanced oil return valve is connected with the port B of the multiple directional control valve. The throttling valve and the balanced oil return valve are both connected with an oil tank through a switching valve. According to the return oil diversion system for the telescopic boom oil cylinder of the high altitude work vehicle, the balanced oil return valve is added between the port A and the port B of the multiple directional control valve, and the throttling valve is added at the port B of the multiple directional control valve for oil return at the same time, so that the purpose of return oil diversion is achieved, and the problems of impact and shaking generated when the oil cylinder starts to retract are solved.

The invention relates to the technical field of bulldozers, in particular to a hydraulic system of a bulldozer. The hydraulic system comprises a first oil way and a second oil way. Oil of the first oil way sequentially passes a pump I, an unloading valve, an energy accumulator and a decompression valve by means of an oil tank to be divided into two paths, one path is communicated with a speed change valve, and the other path is communicated with a steering brake valve. Oil of the second oil way sequentially passes a pump II, a torque converter, a back pressure valve and an oil cooler by means of the oil tank and returns to the oil tank, and a torque converter overflow valve is disposed between an inlet of the torque converter and an outlet of the oil cooler. The unloading valve is connected with an outlet of the pump II. The pump I and the pump II serve as power sources of the hydraulic system of the bulldozer, system power is reasonably allocated, and overflow loss is effectively reduced. Besides, the energy accumulator and the unloading valve are arranged, and the characteristic that flow required by a clutch is large at the moment of shifting is preferentially ensured. Meanwhile, power loss of the hydraulic pumps is reduced when shifting operation is not conducted.

The invention discloses a rotary energy saving system of an excavator. When the excavator rotates to be started, corresponding flow is supplied according to a demand of a rotary motor, so that overflow loss of the system is reduced. A flow control valve is arranged between an overload buffering valve and an oil tank. In a process of accelerating rotary starting, the flow control valve works in a throttling mode; flow, namely overflow of the system, of the flow control valve is calculated according to pressure at an oil inlet of the flow control valve, and the discharge capacity of a hydraulic pump is adjusted according to the overflow of the system; when the overflow is increased, the discharge capacity of the hydraulic pump is reduced, so that most of the pump output flow is absorbed by the rotary motor, and energy loss is reduced; when the overflow is reduced, the discharge cavity of the hydraulic pump is improved, so that the requirement of the rotary motor can be met; moreover, the inlet pressure of the rotary motor is always kept at an overflow pressure value, and the rotary torque is increased, so that the rotary acceleration performance is guaranteed; and in a process of rotary deceleration brake, the flow control valve works in a direct through mode, so that oil can be normally filled into the rotary motor.

A hydraulic circuit controlling preferred movement of a moveable arm to lift or rotate is disclosed, and comprises a rotary motor (12), and a moveable arm lifting oil cylinder (8); a first hydraulic pump (P1), a second hydraulic pump (P2) and a guide oil pump (P3); a moveable arm control valve (7) located in the downstream of the second hydraulic pump (P2) to control hydraulic liquid which is supplied to the moveable arm lifting oil cylinder (8); a rotary control valve (4) located in the downstream of the first hydraulic pump (P1) to control the hydraulic liquid which is supplied to the rotary motor (12) and / or a confluence valve (11); a preferred valve (13) in the downstream of the first hydraulic pump (P1) for dividing the hydraulic liquid of the first hydraulic pump (P1); an electromagnetic valve (15) in the downstream of the guide oil pump (P3) for switching between the states that a guide control oil path (14) of the preferred valve (13) is communicated with the oil tank or communicated with the guide oil pump (P3); and the confluence valve (11) in the downstream of the rotary control valve (4) for controlling the oil path (1) to be communicated with the oil path (3) or an oil return pipeline.

The invention discloses a stacker-reclaimer pitching hydraulic system, a close loop control system and a control method. The system comprises a main loop for controlling the stacker-reclaimer suspension arm pitching mechanism to move, a hydraulic control check valve control loop for providing inverse opening pressure to a hydraulic control check valve, and a manual control loop for supplying power to the system when the system is power-off or has fault. According to the stacker-reclaimer pitching hydraulic system, the close loop control system and the control method, the design requirement is achieved through controlling the speed of the pitching hydraulic cylinder and the vertical displacement of the suspension arm to make sure that the stacker-reclaimer can operate highly efficiently, stably and reliably.