An ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure

Abstract

The present invention discloses an ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure, and belongs to the field of hydraulic technology. The system includes two symmetrically arranged pressure regulating systems; each pressure regulating system is based on a variable pump that supplies oil to a leak-free, low-friction hydraulic cylinder through an electromagnetic ball valve, causing the piston rod to move to a specified position, and injecting oil into the plunger assembly to achieve pressure regulation; when the two pressure regulating systems inject oil into the plunger assembly, one pressure regulating system is filled with hydraulic oil, and the other pressure regulating system is free of hydraulic oil. The plunger assembly is connected to an electric push rod, and a force feedback closed loop is used to push the plunger assembly filled with hydraulic oil to increase pressure and supplement hydraulic system leakage, or to pull the plunger assembly without hydraulic oil to reduce pressure, so that the system pressure is fine-tuned to the target pressure. The present invention can maintain stable pressure output for a long time, eliminate the inherent pulsation characteristics of the hydraulic system, and has high output accuracy, making it suitable for long-term, high-precision output scenario requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and in particular to an ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure. Background Art

[0002] Hydraulic transmission has the characteristics of high power-to-weight ratio and large output force / torque, and is often used in low-speed and high-torque scenarios, such as large torque measurement devices, ship sonar reversing, etc.

[0003] Due to inherent friction and leakage in hydraulic systems, pressure and flow pulsation in the system output is unavoidable. This is particularly pronounced at high system pressures, low speeds, and high output forces / torques. Existing technologies reduce system pulsation and achieve precise output by adding pressure-regulating systems or improving hydraulic components.

[0004] Current hydraulic systems still face challenges with pressure regulation, including a limited adjustment range and low adjustment accuracy. For example, Chinese patent application number 2023104200167 discloses a pressure stabilization method and structure for a variable adjustment mechanism in a hydraulic pump. Currently, efforts to suppress pressure pulsation in hydraulic systems primarily address components, such as optimizing pump structure, designing novel pulsation attenuators and accumulators, and reducing hydraulic pipeline vibration. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the existing technology and propose an ultra-low pulsation, high-precision electro-hydraulic system that can output high pressure and meet the following functions: rapid oil filling, so that the piston rod moves quickly to the specified position, and then the system pressure rises roughly to the pressure set by the relief valve; fine-tuning the output force of the hydraulic cylinder, through force feedback, fine-tuning the system pressure, and making the output force fluctuation of the hydraulic cylinder piston rod small.

[0006] The objectives of the present invention are achieved through the following technical solutions: an ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure, the system comprising two symmetrically arranged pressure regulating systems; each pressure regulating system is based on a variable displacement pump supplying oil to a leak-free, low-friction hydraulic cylinder through an electromagnetic ball valve, causing the piston rod to move to a specified position and injecting oil into the plunger assembly to achieve pressure regulation;

[0007] When the two pressure regulating systems are injecting oil into the plunger assembly, one of the pressure regulating systems is filled with hydraulic oil and the other is empty of hydraulic oil. The plunger assembly is connected to the electric push rod and adopts a force feedback closed loop to push the plunger assembly filled with hydraulic oil to increase the pressure and replenish the leakage of the hydraulic system, or pull the plunger assembly without hydraulic oil to reduce the pressure, so that the system pressure is finely adjusted to the target pressure.

[0008] Furthermore, in the two symmetrically arranged voltage regulating systems, the connection mode and functions of the components in each group are exactly the same.

[0009] Furthermore, in a set of pressure regulating system components: the first motor is connected to the first variable displacement pump in a transmission manner, the oil inlet of the first variable displacement pump is connected to the oil tank through the first filter, and the oil drain port of the first variable displacement pump is connected to the oil tank; the oil outlet of the first variable displacement pump returns to the oil tank through the first overflow valve, and is divided into two ways to connect the two chambers of the first leak-free low-friction hydraulic cylinder through the first pressure reducing valve and the second pressure reducing valve; the oil at the outlet of the first variable displacement pump passes through the third stop valve and the third one-way valve and then passes through the electromagnetic ball valve group and is connected to the first leak-free low-friction hydraulic cylinder; in addition, another oil outlet of the first variable displacement pump passes through the first one-way valve and is connected to the oil circuit of the first electric push rod and the first plunger assembly, one end of the oil circuit is connected to the first stop valve and the first accumulator, and the other end leads to the electromagnetic ball valve group.

[0010] Furthermore, the electromagnetic ball valve group includes a first electromagnetic ball valve, a third electromagnetic ball valve and a fourth electromagnetic ball valve; the A port of the first electromagnetic ball valve is connected to the P ports of the third electromagnetic ball valve and the fourth electromagnetic ball valve.

[0011] Furthermore, the oil at the outlet of the first variable displacement pump is connected to the P1 port of the first solenoid ball valve, and then to the P ports of the third and fourth solenoid ball valves through the A port. The A port of the third solenoid ball valve is connected to the rodless chamber of the first leak-free, low-friction hydraulic cylinder, and the A port of the fourth solenoid ball valve is connected to the rod chamber of the first leak-free, low-friction hydraulic cylinder.

[0012] Furthermore, one end of the oil circuit of the first electric push rod and the first plunger assembly is connected to the first stop valve and the first accumulator, and the other end leads to the P2 port of the first electromagnetic ball valve.

[0013] Furthermore, a radiator and an oil return filter are installed on the oil return line of the oil tank, and a liquid temperature and level gauge is installed on the oil tank.

[0014] Furthermore, in one set of components, a first high-precision force sensor is installed on the piston rod of the first leak-free low-friction hydraulic cylinder to detect real-time displacement data of the piston rod.

[0015] Furthermore, in a group of components, the first motor drives the first variable displacement pump to activate the pump oil, and supplies oil to the first leak-free, low-friction hydraulic cylinder through the electromagnetic ball valve group, so that the piston rod moves quickly to the specified position, and at the same time, oil is injected into the first plunger assembly, and then the system pressure is raised to the set pressure of the first relief valve to achieve rapid oil filling; then, the third stop valve is closed, and the first electric push rod pushes and pulls the first plunger assembly, using a force feedback closed loop to fine-tune the system pressure, reduce pressure fluctuations, and achieve stable output force.

[0016] Beneficial effects of the present invention:

[0017] 1. The present invention is a high-pressure, precise output hydraulic system based on a pulsation-free oil source. Through two-stage pressure regulation, it can achieve rapid positioning and precise fine-tuning. During rapid positioning, the hydraulic cylinder piston rod can be quickly extended to a position that meets assembly requirements. During precise fine-tuning, accuracy is guaranteed, with short adjustment time and high precision.

[0018] 2. After the system pressure is adjusted to the target pressure, it can remain stable. The pulsation-free oil source replenishment of the piston assembly driven by the push rod can achieve fine adjustment and pressure maintenance functions. The system pressure fluctuation is small, so that the force output by the hydraulic cylinder can be kept stable.

[0019] 3. When fine-tuning the pressure, isolating the variable pump through the stop valve can avoid the influence of the pump's pressure pulsation and the dynamic characteristics of the relief valve on the system pressure, thereby improving the pressure regulation accuracy;

[0020] 4. The electric push rod pushes and pulls the plunger assembly to provide a pulsation-free oil source, which has precise control, good synchronization, high transmission efficiency, high positioning accuracy, and fast response, and can achieve high pressure regulation accuracy;

[0021] 5. When fine-tuning the pressure, the electric push rod only moves in one direction, which can avoid the influence of return difference;

[0022] 6. Changing the number of plungers can change the stabilization time, so the stabilization time can be set flexibly. It is suitable for various types of low-pressure and high-torque output scenarios, has a wide range of adaptability, and has great prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic diagram of a high-pressure, precise-output hydraulic system based on a pulsation-free oil source.

[0025] Figure 2 Schematic diagram of the first solenoid ball valve and the second solenoid ball valve.

[0026] Figure 3Schematic diagram of the third, fourth, fifth, and sixth electromagnetic ball valves. 1.1: First filter; 1.2: Second filter; 2.1: First variable displacement pump; 2.2: Second variable displacement pump; 3.1: First motor; 3.2: Second motor; 4.1: First check valve; 4.2: Second check valve; 4.3: Third check valve; 4.4: Fourth check valve; 5.1: First plunger assembly; 5.2: Second plunger assembly; 6.1: First electric push rod; 6.2: Second electric push rod; 7.1: First stop valve; 7.2: Second stop valve; 7.3: Third stop valve; 7.4: Fourth stop valve; 8.1: First accumulator; 8.2: Second accumulator; 9.1: First electromagnetic ball valve; 9.2: , second solenoid ball valve; 9.3, third solenoid ball valve; 9.4, fourth solenoid ball valve; 9.5, fifth solenoid ball valve; 9.6, sixth solenoid ball valve; 10.1, first pressure reducing valve; 10.2, second pressure reducing valve; 10.3, third pressure reducing valve; 10.4, fourth pressure reducing valve; 11.1, first leak-free low-friction hydraulic cylinder; 11.2, second leak-free low-friction hydraulic cylinder; 12, radiator; 13, return oil filter; 14.1, first overflow valve; 14.2, second overflow valve; 15, liquid temperature and level gauge; 16, oil tank; 17, oil filling valve; 18.1, first high-precision force sensor; 18.2, second high-precision force sensor. DETAILED DESCRIPTION

[0027] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. The described embodiments are only a portion of the embodiments of the present invention, and are not intended to be exhaustive. In the following description, the terms "upper," "lower," "inner," "outer," "one side," and "the other side" are used to indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are used solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and are therefore not to be construed as limiting the present invention. Furthermore, the terms "one," "two," "three," "four," "five," "six," and "seven" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Unless otherwise expressly specified or limited, the terms "mounted," "provided with," and "connected" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; mechanical or electrical; direct or indirect through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention.

[0028] In order to enable people skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0029] like Figure 1 As shown, this example provides an ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure, including a first filter 1.1, a second filter 1.2, a first variable displacement pump 2.1, a second variable displacement pump 2.2, a first motor 3.1, a second motor 3.2, a first one-way valve 4.1, a second one-way valve 4.2, a third one-way valve 4.3, a fourth one-way valve 4.4, a first plunger assembly 5.1, a second plunger assembly 5.2, a first electric push rod 6.1, a second electric push rod 6.2, a first stop valve 7.1, a second stop valve 7.2, a third stop valve 7.3, a fourth stop valve 7.4, a first accumulator 8.1, a second accumulator 8.2, First solenoid ball valve 9.1, second solenoid ball valve 9.2, third solenoid ball valve 9.3, fourth solenoid ball valve 9.4, fifth solenoid ball valve 9.5, sixth solenoid ball valve 9.6, first pressure-reducing valve 10.1, second pressure-reducing valve 10.2, third pressure-reducing valve 10.3, fourth pressure-reducing valve 10.4, first leak-proof low-friction hydraulic cylinder 11.1, second leak-proof low-friction hydraulic cylinder 11.2, radiator 12, return oil filter 13, first relief valve 14.1, second relief valve 14.2, liquid temperature and level gauge 15, oil tank 16, oil charging valve 17, first high-precision force sensor 18.1, second high-precision force sensor 18.2.

[0030] The first motor 3.1 and the second motor 3.2 are connected to the first variable displacement pump 2.1 and the second variable displacement pump 2.2 via couplings, respectively. The oil inlets of the two variable displacement pumps are connected to the fuel tank 16. The first filter 1.1 and the second filter 1.2 are respectively disposed between the oil inlets of the first variable displacement pump 2.1 and the second variable displacement pump 2.2 and the fuel tank 16. The first relief valve 14.1 and the second relief valve 14.2 are respectively disposed between the oil outlets of the first variable displacement pump 2.1 and the second variable displacement pump 2.2 and the fuel tank 16.

[0031] like Figure 1 、 Figure 2 and Figure 3As shown, the outlets of the first variable displacement pump 2.1 and the second variable displacement pump 2.2 are respectively connected to the oil inlets of the first pressure reducing valve 10.1 and the second pressure reducing valve 10.2, the oil ports of the first plunger assembly 5.1 and the second plunger assembly 5.2, and the P2 ports of the first electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2. The oil outlets of the first pressure reducing valve 10.1, the second pressure reducing valve 10.2, the third pressure reducing valve 10.3, and the fourth pressure reducing valve 10.4 are connected to the anti-leakage ports of the first non-leakage low-friction hydraulic cylinder 11.1 and the second non-leakage low-friction hydraulic cylinder 11.2. The piston rods of the first plunger assembly 5.1 and the second plunger assembly 5.2 are respectively connected to the first electric push rod 6.1 and the second The electric push rod 6.2 is connected, the oil ports of the first plunger assembly 5.1 and the second plunger assembly 5.2 are also connected to the P1 ports of the first electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2 respectively, the A ports of the first electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2 are connected to the P ports of the third electromagnetic ball valve 9.3, the fourth electromagnetic ball valve 9.4, the fifth electromagnetic ball valve 9.5 and the sixth electromagnetic ball valve 9.6, the A ports of the third electromagnetic ball valve 9.3 and the fifth electromagnetic ball valve 9.5 are connected to the rodless chamber of the first leak-free low-friction hydraulic cylinder 11.1 and the first leak-free low-friction hydraulic cylinder 11.2, the A ports of the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6 are connected to the rodless chamber of the first leak-free low-friction hydraulic cylinder The rod chambers of the first and second non-leakage and low-friction hydraulic cylinders 11.1 and 11.2 are connected. The oil drain ports of the first and second non-leakage and low-friction hydraulic cylinders 11.1 and 11.2, and the T-ports of the third, fourth, fifth, and sixth electromagnetic ball valves 9.3, 9.4, 9.5, and 9.6 are connected to the oil tank 16. The first and second non-return valves 4.1 and 4.2 are arranged between the oil ports of the first and second variable displacement pumps 2.1 and 2.2 and the first and second plunger assemblies 5.1 and 5.2. The third and fourth non-return valves 4.3 and 4.4 are arranged between the oil outlet of the variable displacement pump and the oil outlet of the first and second electromagnetic ball valves 9.1, 9.4, 9.5, and 9.6. The first and second accumulators 8.1 and 8.2 are arranged between the oil ports of the first and second plunger assemblies 5.1 and 5.2 and the P1 ports of the first and second solenoid ball valves 9.1 and 9.2. The first and second stop valves 7.1 and 7.2 are arranged between the oil ports of the first and second accumulators 8.1 and 8.2 and the oil ports of the first and second plunger assemblies 5.1 and 5.2. The third stop valve 7.3 is arranged between the oil inlet of the first relief valve 14.1 and the first check valve 4.1. The fourth stop valve 7.4 is arranged between the oil inlet of the second relief valve 14.2 and the second check valve 4.2.

[0032] In order to cool the hydraulic oil and extend the service life of the hydraulic components, the present invention further provides a radiator 12 , which is installed on the oil return line of the oil tank 16 .

[0033] In order to filter out pollutants generated or intruded in the system before returning to the oil tank, the present invention further provides an oil return filter 13 , which is installed on the oil return line of the oil tank 16 .

[0034] In order to better understand the temperature and level of the oil in the oil tank, the present invention is further provided with a liquid temperature and level gauge 15 , which is installed on the oil tank 16 .

[0035] The above-mentioned pressure regulation method of the hydraulic system based on the pulsation-free oil replenishment mechanism is specifically performed according to the following steps:

[0036] The present invention describes a high-pressure, precise output hydraulic system based on a pulsation-free oil source, comprising two symmetrical components, each driving a first, leak-free, low-friction hydraulic cylinder 11.1 and a second, leak-free, low-friction hydraulic cylinder 11.2, to achieve different functional actions. For example, driving the two hydraulic cylinders in opposite, synchronous motion can be applied to a torque-generating tooling structure, achieving stable, high-torque output. This system is not limited to a single drive effect and is applicable to all scenarios requiring stable, high-output operation. Specific instructions for use are as follows:

[0037] S1. Use the motor to drive the first electric push rod 6.1 and the second and 6.2 to move, pull the piston rod of half of the plunger assembly to the bottom end, wait for oil filling, and pull the piston rod of the other half of the plunger assembly to the top end. If oil cannot be filled, it is in the emptying state.

[0038] S2. Open the third stop valve 7.3 and the fourth stop valve 7.4, control the first solenoid ball valve 9.1 and the second solenoid ball valve 9.2 to lose power, the third solenoid ball valve 9.3 and the fifth solenoid ball valve 9.5 to gain power, and the fourth solenoid ball valve 9.4 and the sixth solenoid ball valve 9.6 to lose power. That is, the first solenoid ball valve 9.1 and the second solenoid ball valve 9.2 work in the right position, the third solenoid ball valve 9.3 and the fifth solenoid ball valve 9.5 work in the left position, and the fourth solenoid ball valve 9.4 and the sixth solenoid ball valve 9.6 work in the right position.

[0039] The first portion of hydraulic oil driven by the motor, delivered by first and second variable displacement pumps 2.1 and 2.2, passes sequentially through third stop valve 7.3, fourth stop valve 7.4, first pressure reducing valve 10.1, second pressure reducing valve 10.2, third pressure reducing valve 10.3, and fourth pressure reducing valve 10.4 before entering the anti-leakage ports of first and second non-leakage low-friction hydraulic cylinders 11.1 and 11.2, minimizing leakage from these cylinders. The second portion of hydraulic oil passes sequentially through third stop valve 7.3, fourth stop valve 7.4, first and second check valves 4.1 and 4.2, and the oil ports of first and second plunger assemblies 5.1 and 5.2, filling the plunger assemblies. After filling, only half of the plunger assemblies are filled with hydraulic oil, while the other half are empty. The third portion of hydraulic oil passes sequentially through third stop valve 7.3, fourth stop valve 7.4, first and second check valves 4.1 and 4.2, and the oil ports of first and second plunger assemblies 5.1 and 5.2, filling the plunger assemblies. After flowing through the valves 3, 4th stop valve 7.4, 3rd and 4th check valves 4.3 and 4.4, ports P2 of the first and second solenoid ball valves 9.1 and 9.2, and ports A of the third and fifth solenoid ball valves 9.3 and 9.5, the hydraulic oil enters the rodless chambers of the first and second non-leakage, low-friction hydraulic cylinders 11.1 and 11.2, rapidly extending the piston rods to a position that meets assembly requirements. The system pressure then rises to the set pressures of the first and second relief valves 14.1 and 14.2. The hydraulic oil in the rod chambers of the first and second non-leakage, low-friction hydraulic cylinders 11.1 and 11.2 then flows through ports A of the fourth and sixth solenoid ball valves 9.4 and 9.6, ports T of the fourth and sixth solenoid ball valves 9.4 and 9.6, radiator 12, and return oil filter 13 before returning to the fuel tank 16.

[0040] S3. After the piston rod reaches the designated position that meets the assembly requirements, the third stop valve 7.3 and the fourth stop valve 7.4 are closed, and the first solenoid ball valve 9.1 and the second solenoid ball valve 9.2 are energized. That is, the first solenoid ball valve 9.1 and the second solenoid ball valve 9.2 work in the left position, the third solenoid ball valve 9.3 and the fifth solenoid ball valve 9.5 still work in the left position, and the fourth solenoid ball valve 9.4 and the sixth solenoid ball valve 9.6 still work in the right position.

[0041] The hydraulic oil output by the motor-driven first variable displacement pump 2.1 and the second variable displacement pump 2.2 only passes through the third stop valve 7.3, the fourth stop valve 7.4, the first pressure reducing valve 10.1, the second pressure reducing valve 10.2, the third pressure reducing valve 10.3, and the fourth pressure reducing valve 10.4 in sequence before entering the anti-leakage ports of the first and second non-leakage low-friction hydraulic cylinders 11.1 and 11.2, thereby minimizing leakage from the non-leakage low-friction hydraulic cylinders.

[0042] S4. Utilizing a closed-loop force feedback system, the motor drives the first and second electric push rods 6.1 and 6.2, respectively, to push the oil-filled first and second plunger assemblies 5.1 and 5.2 to increase pressure and compensate for hydraulic system leaks, or to pull the exhausted first and second plunger assemblies 5.1 and 5.2 to reduce pressure, thereby fine-tuning the system pressure to the target. The push rods only move in one direction, minimizing the effects of return stroke. The greater the number of plunger assemblies 5, the longer the pressure stabilization time.

[0043] S5. After loading is completed, the third stop valve 7.3 and the fourth stop valve 7.4 are opened, the first solenoid ball valve 9.1 and the second solenoid ball valve 9.2 are de-energized, the third solenoid ball valve 9.3 and the fifth solenoid ball valve 9.5 are de-energized, and the fourth solenoid ball valve 9.4 and the sixth solenoid ball valve 9.6 are energized. That is, the first and second solenoid ball valves 9.1 and 9.2 work in the right position, the third and fifth solenoid ball valves 9.3 and 9.5 work in the right position, and the fourth and sixth solenoid ball valves 9.4 and 9.6 work in the left position.

[0044] The first part of the hydraulic oil output by the motor-driven first variable displacement pump 2.1 and the second variable displacement pump 2.2 passes through the third stop valve 7.3, the fourth stop valve 7.4, the first pressure reducing valve 10.1, the second pressure reducing valve 10.2, the third pressure reducing valve 10.3, and the fourth pressure reducing valve 10.4 in sequence, and then enters the anti-leakage port of the first non-leakage low-friction hydraulic cylinder 11.1 and the first non-leakage low-friction hydraulic cylinder 11.2, thereby minimizing leakage of the non-leakage low-friction hydraulic cylinder; the second part of the hydraulic oil passes through the third stop valve 7.3, the fourth stop valve 7.4, the first check valve 4.1, the second check valve 4.2, the oil port of the first plunger assembly 5.1, and the second plunger assembly 5.2 in sequence, and then fills the plunger assembly with oil; the third part of the hydraulic oil passes through the The hydraulic oil then flows through the third stop valve 7.3, the fourth stop valve 7.4, the third check valve 4.3, the fourth check valve 4.4, the P2 port of the first solenoid ball valve 9.1 and the second solenoid ball valve 9.2, and the A port of the fourth solenoid ball valve 9.4 and the sixth solenoid ball valve 9.6, and then enters the rod chambers of the first and second non-leakage low-friction hydraulic cylinders 11.1 and 11.2, causing the piston rods to retract. The hydraulic oil in the rodless chambers of the first and second non-leakage low-friction hydraulic cylinders 11.1 and 11.2 passes in sequence through the A port of the third and fifth solenoid ball valves 9.3 and 9.5, the T port of the third and fifth solenoid ball valves 9.3 and 9.5, the radiator 12, the return oil filter 13, and finally flows back to the oil tank 16.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure, characterized in that: The system includes two symmetrically arranged pressure regulating systems; each pressure regulating system is based on a variable pump that supplies oil to a leak-free, low-friction hydraulic cylinder through a solenoid ball valve, causing the piston rod to move to a specified position and injecting oil into the plunger assembly to achieve pressure regulation; In a set of pressure regulating system components: a first motor (3.1) is connected to a first variable displacement pump (2.1) in a transmission manner; an oil inlet of the first variable displacement pump (2.1) is communicated with an oil tank (16) through a first filter (1.1); and an oil drain port of the first variable displacement pump (2.1) is connected to the oil tank (16); an oil outlet of the first variable displacement pump (2.1) returns to the oil tank (16) through a first relief valve (14.1) and is divided into two paths through a first pressure reducing valve (10.1) and a second pressure reducing valve (10.2) to connect to two chambers of a first leak-free low-friction hydraulic cylinder (11.1); an outlet oil of the first variable displacement pump (2.1) passes through a third stop valve (7.3) and a third check valve (4.3) and then passes through an electromagnetic ball valve group to the first leak-free low-friction hydraulic cylinder (11.1). The invention relates to a first variable displacement pump (2.1) and a first variable displacement pump (2.1) having a low-friction hydraulic cylinder (11.1) and a leakage-proof hydraulic cylinder (11.1); in addition, another oil path at the outlet of the first variable displacement pump (2.1) is connected to the oil path of the first electric push rod (6.1) and the first plunger assembly (5.1) through the first one-way valve (4.1); one end of the oil path is connected to the first stop valve (7.1) and the first accumulator (8.1), and the other end leads to the electromagnetic ball valve group; when the two groups of pressure regulating systems inject oil into the plunger assemblies, one group of plunger assemblies is filled with hydraulic oil, and the other group of plunger assemblies is free of hydraulic oil. The plunger assemblies are connected to the electric push rod and adopt a force feedback closed loop to push the plunger assembly filled with hydraulic oil to increase pressure and supplement hydraulic system leakage, or pull the plunger assembly without hydraulic oil to reduce pressure, so that the system pressure is finely adjusted to the target pressure.

2. The ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure according to claim 1, characterized in that: In the two symmetrically arranged voltage regulating systems, the connection methods and functions of the components in each group are exactly the same.

3. The ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure according to claim 1, characterized in that: The electromagnetic ball valve group comprises a first electromagnetic ball valve (9.1), a third electromagnetic ball valve (9.3) and a fourth electromagnetic ball valve (9.4); the A port of the first electromagnetic ball valve (9.1) is connected to the P ports of the third electromagnetic ball valve (9.3) and the fourth electromagnetic ball valve (9.4).

4. The ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure according to claim 3, characterized in that: The oil at the outlet of the first variable displacement pump (2.1) flows to the P1 port of the first electromagnetic ball valve (9.1), and flows to the P ports of the third electromagnetic ball valve (9.3) and the fourth electromagnetic ball valve (9.4) through the A port. The A port of the third electromagnetic ball valve (9.3) is connected to the rodless cavity of the first leak-free low-friction hydraulic cylinder (11.1), and the A port of the fourth electromagnetic ball valve (9.4) is connected to the rod cavity of the first leak-free low-friction hydraulic cylinder (11.1).

5. The ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure according to claim 3, characterized in that: One end of the oil circuit of the first electric push rod (6.1) and the first plunger assembly (5.1) is connected to the first stop valve (7.1) and the first accumulator (8.1), and the other end leads to the P2 port of the first electromagnetic ball valve (9.1).

6. The ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure according to claim 1, characterized in that: A radiator (12) and an oil return filter (13) are installed on the oil return path of the oil tank (16), and a liquid temperature and level gauge (15) is installed on the oil tank (16).

7. The ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure according to claim 1, characterized in that: In one set of components, a first high-precision force sensor (18.1) is installed on the piston rod of a first leak-free low-friction hydraulic cylinder (11.1) to detect real-time displacement data of the piston rod.

8. The ultra-low pulsation, high-precision electro-hydraulic system capable of outputting high pressure according to claim 1, characterized in that: In one set of components, a first motor (3.1) drives a first variable displacement pump (2.1) to pump oil, and supplies oil to a first leak-free low-friction hydraulic cylinder (11.1) through an electromagnetic ball valve group, causing the piston rod to quickly move to a specified position. At the same time, oil is injected into a first plunger assembly (5.1), and then the system pressure is raised to the pressure set by a first relief valve (14.1), thereby achieving rapid oil filling. Then, the third stop valve (7.3) is closed, and a first electric push rod (6.1) pushes and pulls the first plunger assembly (5.1). A force feedback closed loop is used to fine-tune the system pressure, reduce pressure fluctuations, and achieve stable output force.

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