A load-sensing hydraulic system that achieves high efficiency and energy saving through a variable motor

Abstract

The present invention relates to the field of load control technology, and in particular to a load-sensitive hydraulic system that achieves high efficiency and energy saving through a variable motor. The system includes a hydraulic oil tank, a variable hydraulic pump, a proportional multi-way valve, multiple variable motors, a radiator, and a control system. The variable hydraulic pump oil inlet is connected to the high-pressure port of the proportional multi-way valve, the high-pressure oil output port of the proportional multi-way valve is connected to the high-pressure oil port of the variable motor, the variable motor oil return port is connected to the oil return port of the proportional multi-way valve, the proportional multi-way valve oil return port is connected to the radiator oil inlet, and the radiator oil outlet is connected to the hydraulic oil tank. The multiple variable motor pressure sensors, speed sensors, hydraulic pump pressure sensors, and temperature sensors of the control system are respectively connected to the input end of the controller via cables, and the output end of the controller is respectively connected to the control port of the proportional multi-way valve via cables. The system provided by the present invention can meet the use requirements of different working loads and has low operating costs and a long equipment life.

Description

Technical Field

[0001] The present invention relates to the technical field of load control, and in particular to a load-sensitive hydraulic system that achieves high efficiency and energy saving through a variable motor. Background Art

[0002] A load-sensing hydraulic system is a hydraulic circuit that senses system pressure and flow requirements and only provides the pressure and flow required by the load. Currently, load-sensing hydraulic systems are widely used in engineering machinery and decontamination vehicles. Today's load-sensing hydraulic systems have solved technical problems such as a single pump pulling multiple loads, multiple loads operating simultaneously, and interference between loads. The load-sensing system automatically matches the flow rate according to the load demand, so the system does not have excess flow discharged through the overflow valve, saving energy loss caused by excess flow and improving the energy utilization rate of the hydraulic system compared to other hydraulic systems.

[0003] Disadvantages of existing load-sensing hydraulic systems:

[0004] 1. The system pressure of a load-sensitive hydraulic system is determined by the load with the highest pressure requirement. Due to the varying demands placed on the load motors by the equipment, the required flow rates and operating pressures often vary significantly. If the equipment's operating conditions require multiple load motors to operate simultaneously, and one or more of these load motors operates in a low-flow, high-pressure mode while another or more operate in a high-flow, low-pressure mode, significant pressure energy will be wasted in the load motors operating at high flow rates and low pressures. Existing load-sensitive hydraulic systems cannot avoid this energy loss due to pressure loss. This energy loss can be substantial, causing a rapid increase in hydraulic oil temperature and severe system overheating.

[0005] 2. The thermal equilibrium temperature of the existing load-sensitive system is completely determined by the initial design of the equipment. The parameters are fixed and cannot be adjusted. The thermal equilibrium temperature of the hydraulic system varies greatly under different ambient temperatures.

[0006] 3. When the existing load-sensitive system works in a low-temperature environment, the hydraulic system cannot quickly heat up the hydraulic oil and make the hydraulic oil work at the optimal temperature, resulting in a decrease in load control accuracy and a shortened life of hydraulic components. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a load-sensitive hydraulic system that can meet the load usage requirements of different working conditions, reduce equipment operating costs, and increase equipment service life, and achieve high efficiency and energy saving through a variable motor.

[0008] The present invention is achieved through the following technical solutions:

[0009] A load-sensitive hydraulic system that achieves high efficiency and energy saving through variable motors includes a hydraulic oil tank, a variable hydraulic pump, a proportional multi-way valve, multiple variable motors, a radiator, and a control system. The variable pressure pump has an oil suction port connected to the hydraulic oil tank through an oil suction line, an oil delivery port connected to the high-pressure port of the proportional multi-way valve through a high-pressure line, a high-pressure oil output port of the proportional multi-way valve connected to the high-pressure oil port of the variable motor, an oil return port of the variable motor connected to the oil return port of the proportional multi-way valve through an oil return line, an oil return port of the proportional multi-way valve connected to the oil inlet of the radiator through an oil return line, and an oil outlet of the radiator connected to the hydraulic oil tank through a low-pressure line. The control system includes a controller, variable motor pressure sensors installed at the high-pressure ports of the multiple variable motors, speed sensors installed in the multiple variable motors, a hydraulic pump pressure sensor installed at the high-pressure port of the hydraulic pump, and a temperature sensor installed at the oil inlet of the radiator. The multiple variable motor pressure sensors, speed sensor, hydraulic pump pressure sensor, and temperature sensor are respectively connected to the input end of the controller through cables, and the output end of the controller is respectively connected to the control port of the proportional multi-way valve through cables.

[0010] Further, the hydraulic pump is driven by a prime mover.

[0011] Beneficial effects of the present invention

[0012] A load-sensing hydraulic system that achieves high efficiency and energy saving through a variable displacement motor has the following advantages:

[0013] 1. The highly efficient load-sensitive hydraulic system can greatly meet the use requirements of complex equipment, meet the complex working conditions of multiple load compound actions, and at the same time meet the use requirements of changing load power and speed requirements.

[0014] 2. It can greatly improve the efficiency of hydraulic systems with a large number of loads and large differences in load conditions, reduce equipment operating costs, and achieve energy conservation and emission reduction effects.

[0015] 3. It has the function of hydraulic oil temperature detection and control, which can ensure that the hydraulic system always operates in the optimal oil temperature range and improve the service life of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the system structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the hydraulic principle structure of the present invention;

[0018] Figure 3 Schematic diagram of the control principle of the system of the present invention;

[0019] In the figure: 1. Variable hydraulic pump, 2. Proportional multi-way valve, 3. Variable motor, 4. Variable motor pressure sensor, 5. Speed ​​sensor, 6. Radiator, 7. Hydraulic oil tank, 8. Controller, 9. Hydraulic pump pressure sensor, 10. Temperature sensor, 11. Prime mover. DETAILED DESCRIPTION

[0020] A load-sensitive hydraulic system that achieves high efficiency and energy saving through a variable motor includes a hydraulic oil tank 7, a variable hydraulic pump 1, a proportional multi-way valve 2, multiple variable motors 3, a radiator 6 and a control system. The oil suction port of the variable pressure pump is connected to the hydraulic oil tank through an oil suction line, the oil delivery port is connected to the high-pressure port of the proportional multi-way valve through a high-pressure line, the high-pressure oil output port of the proportional multi-way valve is connected to the high-pressure oil port of the variable motor, the oil return port of the variable motor is connected to the oil return port of the proportional multi-way valve through an oil return line, and the oil return port of the proportional multi-way valve is connected to the oil inlet of the radiator through an oil return line. The oil outlet of the device is connected to the hydraulic oil tank through a low-pressure pipeline. The control system includes a controller 8, a variable motor pressure sensor 4 installed at the high-pressure port of multiple variable motors, a speed sensor 5 installed in multiple variable motors, a hydraulic pump pressure sensor 9 installed at the high-pressure port of the hydraulic pump and a temperature sensor 10 installed at the oil inlet of the radiator. The multiple variable motor pressure sensors, speed sensors, hydraulic pump pressure sensors and temperature sensors are respectively connected to the input end of the controller through cables, and the output end of the controller is respectively connected to the control port of the proportional multi-way valve through cables.

[0021] Furthermore, the hydraulic pump is driven by the prime mover 11 .

[0022] The operating principle of this invention is as follows: the prime mover drives the variable hydraulic pump through a coupling. The variable hydraulic pump draws oil from the hydraulic oil tank through an oil suction line. After absorbing the power of the prime mover, the variable hydraulic pump delivers the high-pressure hydraulic oil to the high-pressure port of the proportional multi-way valve assembly through a high-pressure line. The proportional multi-way valve assembly distributes the hydraulic oil to each load variable motor according to the working conditions, thereby driving each load device. The hydraulic oil released by each load variable motor is collected through a low-pressure line to the return port of the proportional multi-way valve assembly. The return port of the proportional multi-way valve assembly then delivers the hydraulic oil to the radiator via a return line to dissipate the heat. The radiator then returns the hydraulic oil to the hydraulic oil tank via a low-pressure line, completing the hydraulic oil circulation process.

[0023] The control system principle of the present invention is as follows: multiple pressure sensors are used to read the high-pressure port pressure of the corresponding variable motor respectively, the temperature sensor is used to read the hydraulic oil temperature, and multiple speed sensors are used to read the speed of the corresponding variable motor respectively. The controller outputs control signals to the proportional solenoid valves of each working link of the proportional multi-way valve group according to the working conditions. The speed sensor installed at each load variable motor feeds back the speed signal to the controller. The controller compares and calculates the feedback speed signal with the set speed, thereby adjusting the control signal output to the proportional solenoid valve, thereby forming a closed-loop negative feedback control circuit, so that the speed of each load variable motor can be accurately controlled.

[0024] The energy-saving function works as follows: A pressure sensor installed at the high-pressure port of each load variable motor feeds back a pressure signal during operation to the controller. The controller compares the feedback pressure signal with the LS pressure signal. When the feedback pressure signal equals the LS pressure signal, the controller does not adjust the displacement of the variable motor. When the feedback pressure signal is less than the LS pressure signal, the controller adjusts the displacement of the variable motor downward, thereby increasing the pressure at the high-pressure port of the load variable motor until the pressure signal equals the LS pressure signal. Simultaneously, a speed sensor monitors the load speed in real time. If the load speed changes due to displacement adjustment, the controller sends a control signal to the proportional valve to reduce the flow rate through the motor, thereby achieving stable speed control. This ensures stable steady-state speed while reducing the waste of pressure energy in the variable motor, achieving energy savings.

[0025] The system's hydraulic oil temperature is controlled and adjustable as follows: a temperature sensor installed at the radiator feeds the hydraulic oil temperature signal back to the controller, which compares the temperature signal from the temperature sensor with the set hydraulic oil temperature. When the temperature signal from the temperature sensor is lower than the set hydraulic oil temperature, the controller increases the displacement of one of the variable displacement motors, thereby increasing the variable motor's pressure energy consumption and rapidly heating the hydraulic oil to the set temperature. This function can quickly increase the hydraulic oil temperature in low-temperature environments. Users can also set the system hydraulic oil temperature within a certain range and maintain it constant according to their needs, ensuring that the hydraulic system operates at the optimal operating temperature.

[0026] In summary, the load-sensitive hydraulic system protected by the present application, which achieves high efficiency and energy saving through a variable motor, can meet the load usage requirements of different working conditions, reduce equipment operating costs, and increase the service life of the equipment.

[0027] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A load-sensing hydraulic system that achieves high efficiency and energy saving through a variable displacement motor, characterized in that: The radiator is connected to the hydraulic oil tank through a low-pressure pipeline. The prime mover drives the variable hydraulic pump through the coupling. The variable hydraulic pump draws oil from the hydraulic oil tank through the oil suction line. After absorbing the power of the prime mover, the variable hydraulic pump delivers the high-pressure hydraulic oil to the high-pressure port of the proportional multi-way valve through the high-pressure pipeline. The proportional multi-way valve distributes the hydraulic oil to each load variable motor according to the working conditions, thereby driving each load equipment. The hydraulic oil released by each load variable motor is collected to the return port of the proportional multi-way valve through the low-pressure pipeline. The return port of the proportional multi-way valve delivers the hydraulic oil to the radiator through the return oil pipeline for heat dissipation. The radiator delivers the hydraulic oil back to the hydraulic oil tank through the low-pressure pipeline, completing the hydraulic oil circulation process. Multiple variable motor pressure sensors are used to read the pressure at the high-pressure port of the corresponding variable motor, the temperature sensor is used to read the temperature of the hydraulic oil, and the multiple speed sensors are used to read the speed of the corresponding variable motor. The controller outputs control signals to the proportional solenoid valves of each working link of the proportional multi-way valve according to the working conditions. The speed sensors installed at each load variable motor feed back the speed signal to the controller. The controller compares the feedback speed signal with the set speed and adjusts the control signal output by the proportional solenoid valve, thus forming a closed-loop negative feedback control circuit to accurately control the speed of each load variable motor. The pressure sensor installed at the high-pressure port of each load variable motor feeds back the pressure signal of the variable motor when it is working to the controller. The controller compares and calculates the fed-back pressure signal with the LS pressure signal. When the fed-back pressure signal is equal to the LS pressure signal, the controller does not adjust the displacement of the variable motor. When the fed-back pressure signal is less than the LS pressure signal, the controller adjusts the displacement of the variable motor in the direction of reducing the displacement, thereby increasing the pressure at the high-pressure port of the load variable motor until the pressure signal at the high-pressure port of the load variable motor is equal to the LS pressure signal. At the same time, the speed sensor is used to detect the load speed in real time. When the load speed changes due to the displacement adjustment of the variable motor, the controller sends a control signal to the proportional multi-way valve to reduce the flow through the variable motor, thereby achieving stable speed control. The temperature sensor installed at the radiator feeds back the hydraulic oil temperature signal to the controller. The controller compares and calculates the temperature signal fed back by the temperature sensor with the set hydraulic oil temperature. When the temperature signal fed back by the temperature sensor is lower than the set hydraulic oil temperature, the controller adjusts the displacement of one of the variable motors in the direction of increasing the displacement, thereby increasing the consumption of the variable motor's pressure energy and allowing the hydraulic oil to quickly heat up to the set temperature value.

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