Ultralow-pulsation high-precision electro-hydraulic system capable of outputting high voltage

Abstract

The invention discloses an ultralow-pulsation high-precision electro-hydraulic system capable of outputting high pressure, and belongs to the technical field of hydraulic pressure. The system comprises two groups of pressure regulating systems which are symmetrically arranged, each pressure regulating system supplies oil to a leakage-free low-friction hydraulic cylinder through an electromagnetic ball valve on the basis of a variable pump, so that a piston rod moves to a designated position and injects oil to a plunger assembly, and pressure regulation is achieved; when the two pressure regulating systems inject oil into the plunger assembly, one pressure regulating system is filled with hydraulic oil, the other pressure regulating system does not have hydraulic oil, the plunger assembly is connected with the electric push rod, and a force feedback closed loop is adopted to push the plunger assembly filled with the hydraulic oil to increase pressure and supplement leakage of the hydraulic system. Or the plunger assembly without the hydraulic oil is pulled to reduce the pressure, so that the system pressure is accurately adjusted to the target pressure. Long-time pressure maintaining and stable output can be achieved, the inherent pulsation characteristic of a hydraulic system is eliminated, the output precision is high, and the long-time high-precision output scene requirement is met.

Description

Technical Field

[0001] The 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 scenarios with low speed and high torque, such as large torque measurement devices, ship sonar commutation, etc.

[0003] Due to the inherent friction, leakage and other characteristics of the hydraulic system, the pressure and flow pulsation of the system output is difficult to avoid, especially when the system pressure is high, the output force / torque is large at low speed. The existing technology reduces the system pulsation by adding a pressure regulating system or improving the hydraulic components to obtain accurate output.

[0004] The current hydraulic system still has problems in pressure regulation, such as insufficient adjustment range and low adjustment accuracy. For example, Chinese patent: Application No. 2023104200167 discloses a hydraulic pump variable adjustment mechanism pressure stabilization method and pressure stabilization structure. At present, the suppression of pressure pulsation in hydraulic systems mostly starts from components, and reduces pressure pulsation by optimizing the structure of the pump, designing new 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 prior art and to propose an ultra-low pulsation high-precision electro-hydraulic system that can output high pressure and can meet the following functions: rapid oil filling to allow the piston rod to quickly move to a specified position, and then allow the system pressure to rise roughly to the set pressure of the relief valve; fine-tune the output force of the hydraulic cylinder, through force feedback, fine-tune the system pressure, and reduce the fluctuation of the output force of the hydraulic cylinder piston rod.

[0006] The object of the present invention is achieved through the following technical solutions: an ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure, the system comprising two sets of symmetrically arranged pressure regulating systems; each set of pressure regulating systems is based on a variable pump supplying oil to a leak-free low-friction hydraulic cylinder through an electromagnetic ball valve, so that the piston rod moves to a specified position and injects oil into the plunger assembly to achieve pressure regulation; When the two pressure regulating systems are injecting oil into the plunger assemblies, 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 a force feedback closed loop is used to push the plunger assembly filled with hydraulic oil to increase the pressure and replenish the leakage of the hydraulic system, or to pull the plunger assembly without hydraulic oil to reduce the pressure, so that the system pressure can be fine-tuned to the target pressure.

[0007] Furthermore, in the two symmetrically arranged voltage regulating systems, the connection mode and functions between the components in each group are completely the same.

[0008] 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 in one way, 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 pump is connected to the first leak-free low-friction hydraulic cylinder after passing through the third stop valve and the third one-way valve and the electromagnetic ball valve group; in addition, another oil outlet of the first variable pump is connected to the oil circuit of the first electric push rod and the first plunger assembly through the first one-way valve, 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.

[0009] 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.

[0010] Furthermore, the oil at the outlet of the first variable pump flows to the P1 port of the first solenoid ball valve, and flows 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 leakage-free low-friction hydraulic cylinder, and the A port of the fourth solenoid ball valve is connected to the rod chamber of the first leakage-free low-friction hydraulic cylinder.

[0011] 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.

[0012] 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.

[0013] Furthermore, in one set of components, a first high-precision force sensor is installed on the piston rod of the leak-free low-friction hydraulic cylinder to detect the real-time displacement data of the piston rod.

[0014] Furthermore, in a group of components, the first motor drives the first variable pump to 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 overflow 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.

[0015] Beneficial effects of the present invention: 1. The high-pressure precise output hydraulic system based on a pulsation-free oil source of the present invention realizes rapid positioning and precise fine-tuning through two-stage pressure regulation: during rapid positioning, the piston rod of the hydraulic cylinder can be quickly extended to a position that meets the assembly requirements, and during precise fine-tuning, the accuracy is guaranteed, the adjustment time is short, and the accuracy is high; 2. After the system pressure is adjusted to the target pressure, it can remain stable. The fine adjustment and pressure maintenance functions are achieved by replenishing the pulsation-free oil source of the piston assembly driven by the push rod. The system pressure fluctuates little, so that the force output by the hydraulic cylinder can remain stable. 3. When fine-tuning the pressure, the variable pump can be isolated by the stop valve to avoid the influence of the pressure pulsation of the pump and the dynamic characteristics of the overflow valve on the system pressure, thereby improving the pressure regulation accuracy; 4. The electric push rod pushes and pulls the plunger assembly to provide a pulsation-free oil source, with precise control, good synchronization, high transmission efficiency, high positioning accuracy, and fast response, which can achieve high pressure regulation accuracy; 5. When fine-tuning the pressure, the electric push rod only moves in one direction, which can avoid the influence of the return difference; 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-force / torque output scenarios, with a wide range of adaptability and great prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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.

[0017] Figure 1 The schematic diagram of a high-pressure precise output hydraulic system based on a pulsation-free oil source.

[0018] Figure 2 Schematic diagram of the first solenoid ball valve and the second solenoid ball valve.

[0019] Figure 3 Schematic diagram of the third electromagnetic ball valve, the fourth electromagnetic ball valve, the fifth electromagnetic ball valve and the sixth electromagnetic ball valve.

[0020] Among them, 1.1, the first filter; 1.2, the second filter; 2.1, the first variable displacement pump; 2.2, the second variable displacement pump; 3.1, the first motor; 3.2, the second motor; 4.1, the first one-way valve; 4.2, the second one-way valve; 4.3, the third one-way valve; 4.4, the fourth one-way valve; 5.1, the first plunger assembly; 5.2, the second plunger assembly; 6.1, the first electric push rod; 6.2, the second electric push rod; 7.1, the first stop valve; 7.2, the second stop valve; 7.3, the third stop valve; 7.4, the fourth stop valve; 8.1, the first accumulator; 8.2, the second accumulator; 9.1, the first electromagnetic ball valve; 9.2 , the second electromagnetic ball valve; 9.3, the third electromagnetic ball valve; 9.4, the fourth electromagnetic ball valve; 9.5, the fifth electromagnetic ball valve; 9.6, the sixth electromagnetic ball valve; 10.1, the first pressure reducing valve; 10.2, the second pressure reducing valve; 10.3, the third pressure reducing valve; 10.4 the fourth pressure reducing valve; 11.1, the first leak-free low-friction hydraulic cylinder; 11.2, the second leak-free low-friction hydraulic cylinder; 12, the radiator; 13, the return oil filter; 14.1, the first overflow valve; 14.2, the second overflow valve; 15, the liquid temperature and level gauge; 16, the oil tank; 17, the oil filling valve; 18.1, the first high-precision force sensor; 18.2, the second high-precision force sensor. DETAILED DESCRIPTION

[0021] Next, the technical scheme in the embodiment of the present invention will be clearly and completely described in conjunction with the drawings in the embodiment of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. In the following description, it is particularly noted that the orientation or position relationship indicated by the terms "upper", "lower", "inner", "outer", "one side", "the other side", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "one", "two", "three", "four", "five", "six", and "seven" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0022] In order to enable those 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 of the embodiments.

[0023] 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 check valve 4.1, a second check valve 4.2, a third check valve 4.3, a fourth check 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, The first electromagnetic ball valve 9.1, the second electromagnetic ball valve 9.2, the third electromagnetic ball valve 9.3, the fourth electromagnetic ball valve 9.4, the fifth electromagnetic ball valve 9.5, the sixth electromagnetic ball valve 9.6, 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, the first leak-free low-friction hydraulic cylinder 11.1, the second leak-free low-friction hydraulic cylinder 11.2, the radiator 12, the return oil filter 13, the first overflow valve 14.1, the second overflow valve 14.2, the liquid temperature and level gauge 15, the oil tank 16, the oil filling valve 17, the first high-precision force sensor 18.1 and the second high-precision force sensor 18.2.

[0024] The first motor 3.1 and the second motor 3.2 are connected to the first variable pump 2.1 and the second variable pump 2.2 through couplings, respectively. The oil inlets of the two variable pumps are connected to the oil tank 16. The first filter 1.1 and the second filter 1.2 are respectively arranged between the oil inlets of the first variable pump 2.1 and the second variable pump 2.2 and the oil tank 16. The first relief valve 14.1 and the second relief valve 14.2 are respectively arranged between the oil outlets of the first variable pump 2.1 and the second variable pump 2.2 and the oil tank 16. like Figure 1 , Figure 2 and Figure 3As shown, the outlets of the first variable pump 2.1 and the second variable 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, the first electromagnetic ball valve 9.1, and the P2 port of 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 electric push rod 6.2. 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 11.1 and the first leak-free low-friction hydraulic cylinder 11.2. The rod chambers of the hydraulic cylinder 11.1 and the second leak-free low-friction hydraulic cylinder 11.2 are connected, the oil drain ports of the first leak-free low-friction hydraulic cylinder 11.1 and the second leak-free low-friction hydraulic cylinder 11.2, the T 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 are connected to the oil tank 16, the first check valve 4.1 and the second check valve 4.2 are arranged between the oil ports of the first variable displacement pump 2.1, the second variable displacement pump 2.2 and the first plunger assembly 5.1, the second plunger assembly 5.2, the third check valve 4.3 and the fourth check valve 4.4 are arranged between the oil outlet of the variable pump 2 and the first electromagnetic ball valve 9.1, the fourth electromagnetic ball valve 9.4, the fifth electromagnetic ball valve 9.5 and the sixth electromagnetic ball valve 9.6 The first accumulator 8.1 and the second accumulator 8.2 are arranged between the oil ports of the first plunger assembly 5.1 and the second plunger assembly 5.2 and the P1 ports of the first and second electromagnetic ball valves 9.1 and 9.2, the first stop valve 7.1 and the second stop valve 7.2 are arranged between the oil ports of the first accumulator 8.1 and the second accumulator 8.2 and the oil ports of the first plunger assembly 5.1 and the second plunger assembly 5.2, the third stop valve 7.3 is arranged between the oil inlet of the first overflow valve 14.1 and the first check valve 4.1, and the fourth stop valve 7.4 is arranged between the oil inlet of the second overflow valve 14.2 and the second check valve 4.2.

[0025] 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 .

[0026] 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 .

[0027] 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 liquid level gauge 15 , which is installed on the oil tank 16 .

[0028] The above-mentioned pressure regulating method of the hydraulic system based on the pulsation-free oil replenishing mechanism is specifically carried out according to the following steps: The high-pressure precise output hydraulic system based on a pulsation-free oil source described in the present invention has two symmetrical groups of components, which respectively drive the first leak-free low-friction hydraulic cylinder 11.1 and the second leak-free low-friction hydraulic cylinder 11.2 to achieve different functional actions. For example, driving the two groups of hydraulic cylinders to move in opposite directions synchronously can be actuated on a tooling structure that can generate torque to achieve stable and high-torque output. It is hereby explained that the system of the present invention is not limited to a single driving effect, and is suitable for all scenarios that require stable and high output. The specific method of use is as follows: S1. Drive the first electric push rod 6.1 and the second and 6.2 to move through the motor, pull the piston rod of half of the plunger assembly to the bottom, wait for oil filling, and pull the piston rod of the other half of the plunger assembly to the top. If oil cannot be filled, it is in the emptying state.

[0029] S2, open the third stop valve 7.3 and the fourth stop valve 7.4, control the first electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2 to lose power, the third electromagnetic ball valve 9.3 and the fifth electromagnetic ball valve 9.5 to gain power, and the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6 to lose power, that is, the first electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2 work in the right position, the third electromagnetic ball valve 9.3 and the fifth electromagnetic ball valve 9.5 work in the left position, and the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6 work in the right position.

[0030] 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 turn, and then enters the anti-leakage port of the first non-leakage low-friction hydraulic cylinder 11.1 and the second non-leakage low-friction hydraulic cylinder 11.2, so as to minimize the 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 turn, and then fills the plunger assembly with oil. After the filling is completed, only half of the plunger assembly is filled with hydraulic oil, and the other half of the plunger assembly is free of hydraulic oil; the third 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 turn, and then fills the plunger assembly with oil. After the filling is completed, only half of the plunger assembly is filled with hydraulic oil, and the other half of the plunger assembly is free of hydraulic oil; the third part of the hydraulic oil passes through the third stop valve 7. 3, the fourth stop valve 7.4, the third one-way valve 4.3, the fourth one-way valve 4.4, the first electromagnetic ball valve 9.1, the P2 port of the second electromagnetic ball valve 9.2, the third electromagnetic ball valve 9.3, the fifth electromagnetic ball valve 9.5, and then enter the rodless chamber of the first non-leakage low-friction hydraulic cylinder 11.1 and the second non-leakage low-friction hydraulic cylinder 11.2, so that the piston rod is quickly extended to the position that meets the assembly requirements, and then the system pressure is increased to the set pressure of the first relief valve 14.1 and the second relief valve 14.2. The hydraulic oil in the rod chamber of the first non-leakage low-friction hydraulic cylinder 11.1 and the first non-leakage low-friction hydraulic cylinder 11.2 passes through the A port of the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6, the T port of the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6, the radiator 12, the return oil filter 13, and then flows back to the oil tank 16.

[0031] 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 electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2 are controlled to be energized, that is, the first electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2 work in the left position, the third electromagnetic ball valve 9.3 and the fifth electromagnetic ball valve 9.5 still work in the left position, and the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6 still work in the right position.

[0032] 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, and then enters the anti-leakage port of the first non-leakage low-friction hydraulic cylinder 11.1 and the second non-leakage low-friction hydraulic cylinder 11.2, thereby minimizing the leakage of the non-leakage low-friction hydraulic cylinder.

[0033] S4, adopt force feedback closed loop, drive the first electric push rod 6.1 and the second electric push rod 6.2 through the motor, push the first plunger assembly 5.1 and the second plunger assembly 5.2 filled with oil to increase the pressure and supplement the leakage of the hydraulic system, or pull the empty first plunger assembly 5.1 and the second plunger assembly 5.2 to reduce the pressure, so that the system pressure is fine-tuned to the target pressure. The electric push rod only moves in one direction, which can avoid the influence of the return difference. The more the number of plunger assemblies 5, the longer the pressure stabilization time.

[0034] S5. After loading is completed, the third stop valve 7.3 and the fourth stop valve 7.4 are opened to control the first electromagnetic ball valve 9.1 and the second electromagnetic ball valve 9.2 to lose power, the third electromagnetic ball valve 9.3 and the fifth electromagnetic ball valve 9.5 to lose power, and the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6 to be energized, that is, the first and second electromagnetic ball valves 9.1 and 9.2 work in the right position, the third and fifth electromagnetic ball valves 9.3 and 9.5 work in the right position, and the fourth and sixth electromagnetic ball valves 9.4 and 9.6 work in the left position.

[0035] 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 turn, 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, so as to minimize the 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 turn, and then fills the plunger assembly with oil; the third part of the hydraulic oil passes through the The hydraulic oil flows into the rod chamber of the first non-leakage low-friction hydraulic cylinder 11.1 and the second non-leakage low-friction hydraulic cylinder 11.2 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 first electromagnetic ball valve 9.1, the P2 port of the second electromagnetic ball valve 9.2, the A port of the fourth electromagnetic ball valve 9.4 and the sixth electromagnetic ball valve 9.6, and then returns to the oil tank 16 after the hydraulic oil flows into the rod chamber of the first non-leakage low-friction hydraulic cylinder 11.1 and the second non-leakage low-friction hydraulic cylinder 11.2, and then returns to the oil tank 16 after the hydraulic oil flows into the rod chamber of the first non-leakage low-friction hydraulic cylinder 11.1 and the second non-leakage low-friction hydraulic cylinder 11.2 in turn through the A port of the third electromagnetic ball valve 9.3 and the fifth electromagnetic ball valve 9.5, the T port of the third electromagnetic ball valve 9.3 and the fifth electromagnetic ball valve 9.5, the radiator 12, and the return oil filter 13.

[0036] 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 principle of the present invention should be included in the protection scope 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 sets of symmetrically arranged pressure regulating systems; each set of pressure regulating systems is based on a variable pump supplying oil to a leak-free low-friction hydraulic cylinder through an electromagnetic ball valve, so that the piston rod moves to a specified position and injects oil into the plunger assembly to achieve pressure regulation; When the two pressure regulating systems are injecting oil into the plunger assemblies, 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 a force feedback closed loop is used to push the plunger assembly filled with hydraulic oil to increase the pressure and replenish the leakage of the hydraulic system, or to pull the plunger assembly without hydraulic oil to reduce the pressure, so that the system pressure can be fine-tuned 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 method 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: In a set of pressure regulating system components: a first motor (3.1) is transmission-connected to a first variable displacement pump (2.1); an oil inlet of the first variable displacement pump (2.1) is connected to 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 overflow valve (14.1) in one way, and is divided into two ways through a first pressure reducing valve (10.1) and a second pressure reducing valve (10.2) to connect to a first leak-free low-friction fluid outlet (14.1). The first variable pump (2.1) has two chambers; the outlet oil of the first variable pump (2.1) passes through the third stop valve (7.3) and the third check valve (4.3) and then passes through the electromagnetic ball valve group to be connected to the first leak-free low-friction hydraulic cylinder (11.1); in addition, another oil path of the outlet of the first variable pump (2.1) passes through the first check valve (4.1) and is connected to the oil path of the first electric push rod (6.1) and the first plunger assembly (5.1); 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.

4. The ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure according to claim 3, 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).

5. The ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure according to claim 4, characterized in that: The oil at the outlet of the first variable 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-carrying cavity of the first leak-free low-friction hydraulic cylinder (11.1).

6. The ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure according to claim 4, 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).

7. The ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure according to claim 3, characterized in that: A radiator (12) and an oil return filter (13) are installed on the oil return line of the oil tank (16), and a liquid temperature and level gauge (15) is installed on the oil tank (16).

8. The ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure according to claim 3, characterized in that: In one set of components, a first high-precision force sensor (18.1) is installed on the piston rod of a leak-free low-friction hydraulic cylinder (11.1) to detect real-time displacement data of the piston rod.

9. The ultra-low pulsation high-precision electro-hydraulic system capable of outputting high pressure according to claim 3, characterized in that: In one set of components, a first motor (3.1) drives a first variable pump (2.1) to actuate pump oil, and supplies oil to a first leak-free low-friction hydraulic cylinder (11.1) through an electromagnetic ball valve group, so that a piston rod quickly moves to a specified position, and at the same time, oil is injected into a first plunger assembly (5.1), and then the system pressure is raised to a pressure set by a first relief valve (14.1), so as to achieve 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), and a force feedback closed loop is adopted to finely adjust the system pressure, reduce pressure fluctuations, and achieve stable output force.

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