A zero-leakage and low-pressure unloading accumulator control circuit and control method

Abstract

The present application relates to a kind of zero leakage and low pressure unloading accumulator control circuit and control method, belong to hydraulic system technical field, solve the problems that hydraulic pump in prior art in hydraulic system cannot effectively low pressure unloading, hydraulic cylinder is extended slowly, energy utilization efficiency is low and oil source device is difficult to realize miniaturization light weight.The accumulator control circuit includes: oil tank, for storing hydraulic oil;Hydraulic pump, by motor drive, output high pressure oil;The oil outlet of hydraulic pump is connected with the first two-position two-way cartridge valve, the second two-position two-way cartridge valve and the valve port of second unloading valve respectively;The other valve port of the first two-position two-way cartridge valve is connected with the valve port of the rodless chamber of hydraulic cylinder, the other valve port of the second two-position two-way cartridge valve is connected with accumulator;The valve port of the first unloading valve is connected with the valve port of hydraulic cylinder, and the other valve port is connected with the oil inlet of oil tank;The other end of the second unloading valve is connected with the oil inlet of oil tank.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system technology, and in particular to an accumulator control circuit and control method with zero leakage and low-pressure unloading. Background Technology

[0002] In modern industrial production, hydraulic systems are widely used in various types of machinery due to their advantages such as high power density and precise control performance. Accumulators, as key components of hydraulic systems, store and release hydraulic energy, playing a crucial role in improving system response speed and work efficiency. However, in practical applications, the performance of the accumulator control circuit has a significant impact on the stability of the entire hydraulic system, energy consumption, and the miniaturization of the equipment.

[0003] Currently, traditional accumulator control circuits have many drawbacks. On the one hand, when the hydraulic cylinder is not moving, it is impossible to effectively unload the hydraulic pump at low pressure, causing the hydraulic pump to operate under high pressure continuously. This not only wastes a lot of energy but also generates excessive heat in the system, affecting the service life of the equipment. On the other hand, during the extension of the hydraulic cylinder, it often relies solely on the hydraulic pump for oil supply, resulting in a slow extension speed that is difficult to meet the needs of some applications with high efficiency requirements. Moreover, to ensure the working performance of the hydraulic cylinder, a high-power motor and a large-displacement hydraulic pump are usually required, making the entire oil source device bulky and heavy, which is not conducive to the miniaturization and lightweight design of the equipment. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a zero-leakage and low-pressure unloading accumulator control circuit and control method to solve the problems in existing hydraulic systems, such as the inability of hydraulic pumps to effectively unload at low pressure, slow extension speed of hydraulic cylinders, low energy utilization efficiency, and difficulty in miniaturizing and lightweighting oil source devices.

[0005] On one hand, embodiments of the present invention provide an accumulator control circuit with zero leakage and low-pressure unloading, the accumulator control circuit including: an oil tank, a hydraulic pump, a motor, a first two-position two-way cartridge valve, a second two-position two-way cartridge valve, a first unloading valve, a second unloading valve, and an accumulator;

[0006] Oil tank, used to store hydraulic oil;

[0007] The hydraulic pump, driven by an electric motor, outputs high-pressure oil; the oil outlet of the hydraulic pump is connected to one port of the first two-position two-way cartridge valve, the second two-position two-way cartridge valve, and the second unloading valve.

[0008] The other port of the first two-position two-way cartridge valve is connected to the valve port of the rodless chamber of the hydraulic cylinder, and the other port of the second two-position two-way cartridge valve is connected to the accumulator.

[0009] One valve port of the first unloading valve is connected to the valve port of the hydraulic cylinder, and the other valve port is connected to the oil inlet of the oil tank;

[0010] The other end of the second unloading valve is connected to the oil inlet of the oil tank.

[0011] As a further improvement to this application, the zero-leakage and low-pressure unloading accumulator control circuit further includes:

[0012] The check valve has an inlet port connected to the outlet port of the hydraulic pump, and an outlet port connected to one of the first two-position two-way cartridge valves, the second two-position two-way cartridge valve, and the second unloading valve.

[0013] As a further improvement to this application, the zero-leakage and low-pressure unloading accumulator control circuit further includes:

[0014] The throttle valve is connected between the rodless chamber of the hydraulic cylinder and the first and second position two-way cartridge valves. It is used to control the movement speed of the hydraulic cylinder by adjusting the flow rate of the oil entering the hydraulic cylinder.

[0015] As a further improvement to this application, the zero-leakage and low-pressure unloading accumulator control circuit further includes:

[0016] The relief valve has its inlet connected to the outlet of the check valve, and its outlet connected to the inlet of the oil tank. The relief valve opens when the oil pressure exceeds the set value.

[0017] As a further improvement to this application, the zero-leakage and low-pressure unloading accumulator control circuit also includes a pressure sensor installed inside the accumulator bladder to detect the internal pressure of the accumulator.

[0018] As a further improvement of this application, both the first two-position two-way cartridge valve and the second two-position two-way cartridge valve adopt a zero-leakage differential valve core structure, and the opening and closing of the first two-position two-way cartridge valve and the second two-position two-way cartridge valve are controlled by power-on or power-off.

[0019] As a further improvement of this application, a pre-compressed return spring is provided in the rod chamber of the hydraulic cylinder to drive the hydraulic cylinder to retract to its minimum position.

[0020] As a further improvement to this application, the hydraulic pump is a fixed displacement pump.

[0021] On the other hand, embodiments of the present invention provide a control method for an energy storage control circuit, comprising the following steps:

[0022] Step 1: Start the motor to drive the hydraulic pump to work, keep the first two-position two-way cartridge valve and the second two-position two-way cartridge valve in the de-energized closed state, open the first unloading valve and the second unloading valve, so that the oil output by the hydraulic pump is unloaded at low pressure and returned to the oil tank through the second unloading valve.

[0023] Step 2: Energize the second two-position two-way cartridge valve to open and close the second unloading valve, and the oil output by the hydraulic pump charges the accumulator through the second two-position two-way cartridge valve;

[0024] Step 3: When the pressure sensor detects that the internal pressure of the accumulator has reached the set value, the second two-position two-way cartridge valve is de-energized and closed, the second unloading valve is opened, and the oil output by the hydraulic pump is unloaded at low pressure and returned to the oil tank through the second unloading valve.

[0025] Step 4: Simultaneously energize and open the first two-position two-way cartridge valve and the second two-position two-way cartridge valve, and close the first unloading valve and the second unloading valve. The oil from the hydraulic pump and the accumulator merges to drive the piston rod of the hydraulic cylinder to extend rapidly.

[0026] Step 5: After the piston rod of the hydraulic cylinder is fully extended, close the first two-position two-way cartridge valve and open the first unloading valve. The hydraulic cylinder retracts under the action of the return spring. After a preset delay time, close the second two-position two-way cartridge valve and open the second unloading valve. When the oil output by the hydraulic pump is unloaded back to the oil tank under low pressure through the second unloading valve, repeat step 4.

[0027] As a further improvement to this application, the preset delay time in step 5 is determined based on the accumulator's filling time, using the following formula:

[0028] T = K × t c +Δt (1);

[0029] Where T is the preset delay time, t c The actual filling time for the accumulator to charge from the initial pressure to the set pressure; K is the compensation coefficient; Δ is the response time.

[0030] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0031] 1. This invention employs a combination of an accumulator and a two-position two-way cartridge valve for the accumulator. When the hydraulic cylinder is not moving, the accumulator is first charged to reach a high-pressure state. Then, by controlling the opening and closing of the two-position two-way cartridge valve, the hydraulic pump is unloaded at low pressure, avoiding the hydraulic pump from working continuously under unnecessary high pressure, effectively reducing the system's energy consumption, reducing excessive heat generated by high-pressure operation, extending the service life of the hydraulic pump, and improving the stability and reliability of the entire hydraulic system.

[0032] 2. In the operation of the hydraulic cylinder, the hydraulic pump and accumulator simultaneously replenish the hydraulic cylinder with fluid. This coordinated oil supply method enables the hydraulic cylinder to work quickly and significantly improves working efficiency. By replenishing the hydraulic cylinder with oil through the accumulator, the installed power of the system is greatly reduced, while the workload of the hydraulic pump is reduced, the heat generation of the system is reduced, and the energy utilization efficiency is effectively improved.

[0033] 3. This invention significantly reduces the system's power requirements, thus allowing the selection of lower-power motors and smaller displacement hydraulic pumps. This achieves miniaturization and weight reduction of the oil source motor and pump, reducing the equipment's footprint and weight. It not only lowers the equipment's manufacturing cost and installation difficulty but also improves its flexibility and mobility, making it more suitable for various space-constrained applications and applications with strict weight requirements.

[0034] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0035] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0036] Figure 1 A schematic diagram of a zero-leakage and low-pressure unloading accumulator control circuit provided in an embodiment of the present invention;

[0037] Figure 2 This is a schematic flowchart illustrating a control method for a zero-leakage and low-pressure unloading accumulator control circuit according to an embodiment of the present invention. Detailed Implementation

[0038] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0039] Example 1

[0040] A specific embodiment of the present invention discloses an accumulator control circuit with zero leakage and low-pressure unloading, such as... Figure 1 As shown.

[0041] The accumulator control circuit includes: oil tank 1, hydraulic pump 3, motor 4, first two-position two-way cartridge valve 9, second two-position two-way cartridge valve 11, first unloading valve 10, second unloading valve 12, and accumulator 13.

[0042] Oil tank 1 is used to store hydraulic oil; hydraulic pump 3 is driven by motor 4 and outputs high-pressure oil; the oil outlet of hydraulic pump 3 is connected to one valve port of first two-position two-way cartridge valve 9, second two-position two-way cartridge valve 11 and second unloading valve 12 respectively; the other valve port of first two-position two-way cartridge valve 9 is connected to the valve port of rodless chamber of hydraulic cylinder 5, and the other valve port of second two-position two-way cartridge valve 11 is connected to accumulator 13; one valve port of first unloading valve 10 is connected to the valve port of hydraulic cylinder 5, and the other valve port is connected to the oil inlet of oil tank; the other end of second unloading valve 12 is connected to the oil inlet of oil tank 1.

[0043] Specifically, the oil tank is an oil storage device in a hydraulic system, its function being to store hydraulic oil and provide oil supply to the system. Simultaneously, the oil tank also serves functions such as heat dissipation and sedimentation of impurities. In this application, the oil tank 1 adopts a sealed design to prevent oil leakage and isolate external impurities from entering the tank, ensuring the cleanliness of the hydraulic oil.

[0044] The hydraulic pump 3 is a device that converts mechanical energy into hydraulic energy and serves as the power source for the hydraulic system. In this application, the hydraulic pump 3 is driven by the motor 4. The hydraulic pump 3 is a fixed displacement pump, which, driven by the motor 4, draws hydraulic oil from the oil tank 1 and outputs high-pressure oil at a preset pressure and flow rate. The outlet of the hydraulic pump 3 is connected to one port of the first two-position two-way cartridge valve 9, the second two-position two-way cartridge valve 11, and the second unloading valve 12.

[0045] The motor 4 is a device that provides power to the hydraulic pump 3. It can be a three-phase asynchronous motor. The motor 4 is connected to the hydraulic pump 3 through mechanical connection methods such as couplings. When the motor 4 is powered on and started, the rotational motion of its output shaft is transmitted to the hydraulic pump 3, driving the hydraulic pump 3 to work and realizing the conversion of mechanical energy into hydraulic energy.

[0046] A 2-position 2-way cartridge valve is a hydraulic valve used in hydraulic systems to control the flow of hydraulic fluid. "2-position" refers to the valve's two different operating positions, corresponding to the open and closed states of the valve port. These two positions can be switched using an external control signal (such as an electromagnetic control signal), and "2-way" indicates that the valve has two ports.

[0047] One valve port is connected to the oil outlet of the hydraulic pump 3, and the other valve port is connected to the valve port of the rodless chamber of the hydraulic cylinder 5. When the first two-position two-way cartridge valve 9 is in the open position, the two valve ports are connected, and the high-pressure oil output by the hydraulic pump 3 can flow in from the valve port connected to the hydraulic pump 3, and then flow out from the valve port connected to the rodless chamber of the hydraulic cylinder 5, and then enter the rodless chamber of the hydraulic cylinder 5, pushing the piston rod of the hydraulic cylinder 5 to extend. When it is in the closed position, the passage between the two valve ports is blocked, and the oil cannot pass through, thereby preventing the oil from flowing to the hydraulic cylinder 5, and realizing the control of the action of the hydraulic cylinder 5.

[0048] For the second two-position two-way cartridge valve 11, one valve port is connected to the oil outlet of the hydraulic pump 3, and the other valve port is connected to the accumulator 13. When the second two-position two-way cartridge valve 11 is in the open position, the two valve ports are connected, and the high-pressure oil output by the hydraulic pump 3 can flow in from the valve port connected to the hydraulic pump 3, and then flow out from the valve port connected to the accumulator 13, entering the accumulator 13 to realize the filling of the accumulator 13; when it is in the closed position, the passage between the two valve ports is cut off, preventing oil from entering the accumulator 13, so as to maintain the pressure stability in the accumulator 13.

[0049] Furthermore, both the first and second position two-way cartridge valves 9 and 11 employ a zero-leakage differential valve core structure, controlling their opening and closing via energization or de-energization. The differential valve core consists of a main valve core and a pilot valve core. The main valve core controls the opening and closing of the main port, while the pilot valve core controls the movement of the main valve core. When the cartridge valve is closed, the main valve core is pressed tightly against the valve seat under the pilot pressure and spring force, preventing oil leakage from the main port, thus achieving zero leakage.

[0050] In the differential valve core structure, high-performance sealing materials (such as rubber sealing rings or polytetrafluoroethylene sealing rings) are used in the sealing parts of the valve core. These sealing materials have good elasticity and wear resistance, and can fit tightly against the surfaces of the valve core and valve seat, effectively preventing oil leakage.

[0051] The first and second position two-way cartridge valve 9 and the second and second position two-way cartridge valve 11 can also be equipped with electromagnetic coils. When the electromagnetic coil is energized, it generates electromagnetic force, which drives the pilot valve core to move, thereby controlling the movement of the main valve core and opening the cartridge valve. When the electromagnetic coil is de-energized, the electromagnetic force disappears, and under the action of spring force or pilot pressure, the main valve core resets and the cartridge valve closes.

[0052] An unloading valve is used to control the unloading of a hydraulic pump or other hydraulic components. By controlling the opening and closing of its valve port, the pressure of the hydraulic system can be regulated under different operating conditions. The first unloading valve 10 includes two valve ports: one port is connected to the valve port of the rodless chamber of the hydraulic cylinder 5, and the other port is connected to the oil inlet of the oil tank. When the first unloading valve 10 is in the open state, the two valve ports are connected, and the oil in the hydraulic cylinder 5 can flow in from the valve port connected to the hydraulic cylinder 5 and then flow out from the valve port connected to the oil inlet of the oil tank, flowing back to the oil tank 1, thereby achieving the unloading of the hydraulic cylinder 5. At this time, the piston rod of the hydraulic cylinder 5 retracts under the action of external load or internal spring force. When the first unloading valve 10 is in the closed state, the passage between the two valve ports is blocked, and the oil cannot flow from the hydraulic cylinder 5 back to the oil tank 1, and the hydraulic cylinder 5 remains in its current state.

[0053] The second unloading valve 12 also has two ports. One port is connected to the outlet of the hydraulic pump 3, and the other port is connected to the inlet of the oil tank 1. When the second unloading valve 12 is open, the two ports are connected, and the oil output by the hydraulic pump 3 can flow in from the port connected to the hydraulic pump 3 and then flow out from the port connected to the oil tank 1, directly returning to the oil tank 1. At this time, the hydraulic pump 3 is in a low-pressure unloading state, and the output oil does not need to pass through other high-pressure working components, reducing the system's energy consumption and heat generation. When the second unloading valve 12 is closed, the passage between the two ports is cut off, and the oil output by the hydraulic pump 3 flows to the hydraulic cylinder 5 through the first two-position two-way cartridge valve 9 or to the accumulator 13 through the second two-position two-way cartridge valve 11.

[0054] Accumulator 13 is a device in a hydraulic system that can store and release hydraulic energy. When accumulator 13 is in a charged state, the second two-position two-way cartridge valve 11 is opened, and the high-pressure oil output by hydraulic pump 3 flows into the accumulator 13 through one of the valve ports of the second two-position two-way cartridge valve 11. As the oil continuously flows in, hydraulic energy is stored.

[0055] When the hydraulic cylinder 5 needs to be driven to work quickly, the first two-position two-way cartridge valve 9 and the second two-position two-way cartridge valve 11 are opened simultaneously. The high-pressure oil stored in the accumulator 13 flows out from the second two-position two-way cartridge valve 11 and merges with the oil output by the hydraulic pump 3. It then enters the rodless chamber of the hydraulic cylinder 5 through the first two-position two-way cartridge valve 9, pushing the piston rod of the hydraulic cylinder 5 to extend quickly, thus releasing energy. The auxiliary hydraulic pump 3 provides power to the hydraulic cylinder 5, improving the working efficiency of the hydraulic cylinder 5.

[0056] Furthermore, the zero-leakage and low-pressure unloading accumulator control circuit also includes:

[0057] The one-way valve 6 has its inlet connected to the outlet of the hydraulic pump 3, and its outlet connected to one port of the first two-position two-way cartridge valve 9, the second two-position two-way cartridge valve 11, and the second unloading valve 12.

[0058] A one-way valve (6) is used to control the unidirectional flow of hydraulic fluid. Its basic structure typically includes a valve body, a valve core, and a spring. Under the action of the spring, the valve core normally blocks the passage for reverse flow of hydraulic fluid. When hydraulic fluid flows in from the inlet with sufficient pressure, the pressure of the hydraulic fluid overcomes the spring force, pushing the valve core to move and opening the flow passage, allowing the hydraulic fluid to flow smoothly from the inlet to the outlet. However, when hydraulic fluid attempts to flow back from the outlet, the valve core, under the combined action of the spring force and the reverse hydraulic pressure, tightly blocks the passage, preventing backflow.

[0059] When motor 4 drives hydraulic pump 3 to work, hydraulic pump 3 draws hydraulic oil from oil tank 1 and outputs high-pressure oil. The high-pressure oil enters the inlet of check valve 6 at a certain pressure. This pressure overcomes the elastic force of the spring inside check valve 6, pushing the valve core to move and opening the oil passage. At this time, the oil flows from the inlet to the outlet of check valve 6.

[0060] When the accumulator 13 stores sufficient energy and the pressure increases, or when the hydraulic cylinder 5 generates reverse pressure under external load, without the check valve 6, the oil might flow back to the hydraulic pump 3. This would not only affect the normal operation of the hydraulic pump 3 but could also damage it. The check valve 6 ensures that the reverse oil pressure and spring force work together to block the passage with the valve core, preventing the oil from flowing back to the hydraulic pump 3 and protecting the safe and stable operation of the hydraulic pump 3.

[0061] Furthermore, the zero-leakage and low-pressure unloading accumulator control circuit also includes:

[0062] Throttle valve 8 is connected between the rodless chamber of hydraulic cylinder 5 and the first two-position two-way cartridge valve 9, and is used to control the movement speed of hydraulic cylinder 5 by adjusting the flow rate of oil entering hydraulic cylinder 5.

[0063] The throttle valve 8 regulates the flow rate of oil by changing the flow area of ​​the throttle orifice. Its structure may include a valve body, a valve core, and a regulating device. The valve core can move axially within the valve body, and its position can be changed by the regulating device (such as an adjusting knob), thereby changing the size of the throttle orifice. When the throttle orifice area increases, the resistance to oil flow decreases, and the flow rate increases; conversely, when the throttle orifice area decreases, the resistance to oil flow increases, and the flow rate decreases.

[0064] The movement speed of hydraulic cylinder 5 is directly proportional to the flow rate of oil entering its rodless chamber. The movement speed of hydraulic cylinder 5 is adjusted by regulating the flow rate of oil entering the rodless chamber of hydraulic cylinder 5 through throttle valve 8. When the flow rate of oil entering the rodless chamber of hydraulic cylinder 5 decreases, the extension speed of the piston rod of hydraulic cylinder 5 slows down; when the flow rate of oil entering the rodless chamber of hydraulic cylinder 5 increases, the extension speed of the piston rod of hydraulic cylinder 5 speeds up.

[0065] Furthermore, the zero-leakage and low-pressure unloading accumulator control circuit also includes:

[0066] The overflow valve 7 has its inlet connected to the outlet of the check valve 6 and its outlet connected to the inlet of the oil tank 1. The overflow valve 7 opens when the oil pressure exceeds the set value.

[0067] The function of relief valve 7 is to protect the hydraulic system by providing a channel for oil to flow back to oil tank 1 in case of abnormal pressure, thereby releasing pressure. Relief valve 7 can be composed of valve body, valve core, spring, and adjusting device. The valve core is in the closed state under the preload of the spring. During normal operation of the hydraulic system, the pressure in the oil circuit is always lower than the set pressure of relief valve 7. At this time, the valve core is closed under the action of spring force. The oil output by hydraulic pump 3 flows to accumulator 13 or hydraulic cylinder 5 and other actuators through check valve 6, first two-position two-way cartridge valve 9, second two-position two-way cartridge valve 1, etc., after passing through check valve 6.

[0068] Once the pressure exceeds the preset pressure value of the relief valve 7, the hydraulic pressure acting on the valve core will be greater than the spring preload. At this time, the hydraulic pressure pushes the valve core to move against the spring force, the relief valve 7 opens, and the oil will quickly flow back to the oil tank 1 from the oil inlet of the relief valve 7.

[0069] Furthermore, the zero-leakage and low-pressure unloading accumulator control circuit also includes a pressure sensor 14, installed inside the bladder of the accumulator 13, for detecting the internal pressure of the accumulator 13. The pressure sensor 14 can also be installed on the connecting pipe between the accumulator 13 and the second two-position two-way cartridge valve 11 or near the valve port of the accumulator 13.

[0070] Pressure sensor 14 is used to monitor the internal pressure of the accumulator bladder. When hydraulic pump 3 fills the accumulator 13 with liquid through the second two-position two-way cartridge valve 11, the internal pressure of the accumulator 13 gradually increases. Pressure sensor 14 can convert the pressure signal into a corresponding electrical signal output. When the internal pressure of the accumulator 13 reaches the set upper limit value, the control system will close the second two-position two-way cartridge valve 11 to stop the filling process and prevent excessive pressure from damaging the accumulator 13.

[0071] Example 2

[0072] like Figure 2 As shown, a control method for an energy storage control circuit includes the following steps:

[0073] Step 1: Start the motor 4 to drive the hydraulic pump 3 to work, keep the first two-position two-way cartridge valve 9 and the second two-position two-way cartridge valve 11 in the power-off closed state, open the first unloading valve 10 and the second unloading valve 12, so that the oil output by the hydraulic pump 3 is unloaded at low pressure and returned to the oil tank 1 through the second unloading valve 12.

[0074] When motor 4 is started, its output shaft rotates, driving hydraulic pump 3 to begin operation via couplings and other transmission components. At this time, the first two-position two-way cartridge valve 9 and the second two-position two-way cartridge valve 11 are de-energized, their internal valve cores tightly closing under spring force to prevent oil flow. Simultaneously, the first unloading valve 10 and the second unloading valve 12 open. Hydraulic pump 3 draws hydraulic oil from oil tank 1 and pressurizes it for output. Because the first two-position two-way cartridge valve 9 and the second two-position two-way cartridge valve 11 are closed, the output oil can only flow back to oil tank 1 through the second unloading valve 12. Hydraulic pump 3 is in a low-pressure unloading state, reducing system energy consumption and heat generation, and extending the service life of hydraulic pump 3.

[0075] Step 2: Energize the second two-position two-way cartridge valve 11 to open and close the second unloading valve 12. The oil output by the hydraulic pump 3 charges the accumulator 13 through the second two-position two-way cartridge valve 11.

[0076] When filling the accumulator 13 with fluid, the second two-position two-way cartridge valve 11 is energized. Upon energization, the solenoid coil generates electromagnetic force, overcoming the spring force to move the valve core, thus opening the second two-position two-way cartridge valve 11. Simultaneously, the second unloading valve 12 is closed, cutting off the unloading channel for the oil to flow back to the oil tank 1. At this time, the high-pressure oil output from the hydraulic pump 3 flows through the check valve 6 and then through the opened second two-position two-way cartridge valve 11 to the accumulator 13. As the oil is continuously injected, the pressure inside the accumulator 13 gradually increases, achieving energy storage.

[0077] Step 3: When the pressure sensor 14 detects that the internal pressure of the accumulator 13 reaches the set value, the second two-position two-way cartridge valve 11 is de-energized and closed, the second unloading valve 12 is opened, and the oil output by the hydraulic pump 3 is unloaded at low pressure and returned to the oil tank 1 through the second unloading valve 12.

[0078] A pressure sensor 14 installed inside the accumulator 13 bladder monitors the internal pressure of the accumulator 13 in real time. When the pressure sensor 14 detects that the internal pressure of the accumulator 13 reaches a preset value, the second two-position two-way cartridge valve 11 is de-energized, the valve core resets under the action of spring force, and the valve port closes, preventing oil from continuing to flow into the accumulator 13. At the same time, the second unloading valve 12 is opened, and the oil output by the hydraulic pump 3 is unloaded back to the oil tank 1 under low pressure through the second unloading valve 12, reducing system energy consumption.

[0079] Step 4: Simultaneously energize and open the first two-position two-way cartridge valve 9 and the second two-position two-way cartridge valve 11, and close the first unloading valve 10 and the second unloading valve 12. The oil from the hydraulic pump 3 and the accumulator 13 merges to drive the piston rod of the hydraulic cylinder 5 to extend rapidly.

[0080] When the piston rod of hydraulic cylinder 5 needs to extend rapidly, the first two-position two-way cartridge valve 9 and the second two-position two-way cartridge valve 11 must be energized simultaneously to open them. At the same time, the first unloading valve 10 and the second unloading valve 12 are closed to cut off the unloading passage of the hydraulic fluid. At this time, the hydraulic fluid output from hydraulic pump 3 and the fluid released from accumulator 13 merge and enter the rodless chamber of hydraulic cylinder 5 after passing through check valve 6, the first two-position two-way cartridge valve 9, and throttle valve 8. The pressure of the hydraulic fluid pushes the piston rod of hydraulic cylinder 5 to extend rapidly.

[0081] Step 5: After the piston rod of the hydraulic cylinder 5 is fully extended, close the first two-position two-way cartridge valve 9 and open the first unloading valve 10. The hydraulic cylinder 5 retracts under the action of the return spring. After a preset delay time, close the second two-position two-way cartridge valve 11 and open the second unloading valve 12. When the oil output by the hydraulic pump 3 is unloaded back to the oil tank 1 under low pressure through the second unloading valve 12, step 4 is executed again.

[0082] After the piston rod of hydraulic cylinder 5 is fully extended, the first two-position two-way cartridge valve 9 is closed, cutting off the passage of oil into the rodless chamber of hydraulic cylinder 5. Simultaneously, the first unloading valve 10 is opened, and the oil in the rodless chamber of hydraulic cylinder 5 flows back to oil tank 1 through the first unloading valve 10 under the action of the return spring, causing the piston rod to gradually retract. The purpose of the preset delay time is to ensure that the accumulator 13 has sufficient time to replenish energy during the retraction of hydraulic cylinder 5. After the preset delay time, the second two-position two-way cartridge valve 11 is closed, and the second unloading valve 12 is opened, allowing the oil output by hydraulic pump 3 to be unloaded at low pressure and return to oil tank 1 through the second unloading valve 12. Afterward, the system repeats step 4 to begin the next working cycle, achieving continuous and stable operation of the system.

[0083] The preset delay time is determined based on the filling time of the accumulator 13, using the following formula:

[0084] T = K × t c +Δt (1);

[0085] Where T is the preset delay time, t c The actual filling time for the accumulator (13) to be charged from the initial pressure to the set pressure; K is the compensation coefficient; Δt is the response time.

[0086] The above embodiments of the present invention have at least the following beneficial effects: The present invention employs a combination of an accumulator and a two-position two-way cartridge valve for the accumulator. When the hydraulic cylinder is not moving, the accumulator is first charged to a high-pressure state. Then, by controlling the opening and closing of the two-position two-way cartridge valve, low-pressure unloading of the hydraulic pump is achieved, avoiding continuous operation of the hydraulic pump under unnecessary high pressure, effectively reducing system energy consumption, and simultaneously reducing excessive heat generated by high-pressure operation, extending the service life of the hydraulic pump, and improving the stability and reliability of the entire hydraulic system. During the operation of the hydraulic cylinder, the present invention simultaneously replenishes the hydraulic cylinder with fluid through both the hydraulic pump and the accumulator, achieving a coordinated oil supply... This method enables the hydraulic cylinder to work quickly, significantly improving work efficiency. By replenishing the hydraulic cylinder with oil through an accumulator, the installed power of the system is greatly reduced, while the workload of the hydraulic pump is also reduced, reducing system heat generation and effectively improving energy utilization efficiency. This invention significantly reduces the system's installed power requirements, thus allowing the selection of lower-power motors and smaller displacement hydraulic pumps. This achieves miniaturization and weight reduction of the oil-powered motor and pump, reducing the equipment's footprint and weight. It not only reduces the equipment's manufacturing cost and installation difficulty but also improves its flexibility and mobility, making it more suitable for various space-constrained applications and those with strict weight requirements.

[0087] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A zero-leakage and low-pressure unloading accumulator control circuit, characterized in that, The accumulator control circuit includes: an oil tank (1), a hydraulic pump (3), a motor (4), a first two-position two-way cartridge valve (9), a second two-position two-way cartridge valve (11), a first unloading valve (10), a second unloading valve (12), and an accumulator (13); Oil tank (1), used to store hydraulic oil; The hydraulic pump (3) is driven by the motor (4) and outputs high-pressure oil. The oil outlet of the hydraulic pump (3) is connected to one valve port of the first two-position two-way cartridge valve (9), the second two-position two-way cartridge valve (11), and the second unloading valve (12). The other port of the first two-position two-way cartridge valve (9) is connected to the valve port of the rodless chamber of the hydraulic cylinder (5), and the other port of the second two-position two-way cartridge valve (11) is connected to the accumulator (13). One valve port of the first unloading valve (10) is connected to the valve port of the hydraulic cylinder (5), and the other valve port is connected to the oil inlet of the oil tank; The other end of the second unloading valve (12) is connected to the oil inlet of the oil tank (1).

2. The energy storage control circuit according to claim 1, characterized in that, The zero-leakage and low-pressure unloading accumulator control circuit also includes: The check valve (6) has an inlet connected to the outlet of the hydraulic pump (3) and an outlet connected to one port of the first two-position two-way cartridge valve (9), the second two-position two-way cartridge valve (11), and the second unloading valve (12).

3. The energy storage control circuit according to claim 1, characterized in that, The zero-leakage and low-pressure unloading accumulator control circuit also includes: Throttle valve (8) is connected between rodless chamber of hydraulic cylinder (5) and first two-position two-way cartridge valve (9) and is used to control the movement speed of hydraulic cylinder (5) by adjusting the flow rate of oil entering hydraulic cylinder (5).

4. The energy storage control circuit according to claim 1, characterized in that, The zero-leakage and low-pressure unloading accumulator control circuit also includes: The overflow valve (7) has its inlet connected to the outlet of the check valve (6) and its outlet connected to the inlet of the oil tank (1). The overflow valve (7) opens when the oil pressure exceeds the set value.

5. The energy storage control circuit according to claim 1, characterized in that, The zero-leakage and low-pressure unloading accumulator control circuit also includes a pressure sensor (14), installed inside the bladder of the accumulator (13), for detecting the internal pressure of the accumulator (13).

6. The energy storage control circuit according to claim 1, characterized in that, Both the first two-position two-way cartridge valve (9) and the second two-position two-way cartridge valve (11) adopt a zero-leakage differential valve core structure, and the opening and closing of the first two-position two-way cartridge valve (9) and the second two-position two-way cartridge valve (11) are controlled by power-on or power-off.

7. The energy storage control circuit according to claim 1, characterized in that, A pre-compression reset spring is provided in the rod chamber of the hydraulic cylinder (5) to drive the hydraulic cylinder (5) to retract to its minimum position.

8. The energy storage control circuit according to claim 1, characterized in that, The hydraulic pump (3) is a fixed displacement pump.

9. A control method based on the energy storage control loop according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Start the motor (4) to drive the hydraulic pump (3) to work, keep the first two-position two-way cartridge valve (9) and the second two-position two-way cartridge valve (11) in the power-off closed state, open the first unloading valve (10) and the second unloading valve (12) so that the oil output by the hydraulic pump (3) is unloaded at low pressure and returned to the oil tank (1) through the second unloading valve (12); Step 2: Energize the second two-position two-way cartridge valve (11) to open and close the second unloading valve (12), and the oil output by the hydraulic pump (3) fills the accumulator (13) through the second two-position two-way cartridge valve (11); Step 3: When the pressure sensor (14) detects that the internal pressure of the accumulator (13) reaches the set value, the second two-position two-way cartridge valve (11) is de-energized and closed, the second unloading valve (12) is opened, and the oil output by the hydraulic pump (3) is unloaded at low pressure and returned to the oil tank (1) through the second unloading valve (12). Step 4: Simultaneously power on the first two-position two-way cartridge valve (9) and the second two-position two-way cartridge valve (11), and close the first unloading valve (10) and the second unloading valve (12). The oil from the hydraulic pump (3) and the accumulator (13) merges to drive the piston rod of the hydraulic cylinder (5) to extend rapidly. Step 5: After the piston rod of the hydraulic cylinder (5) is fully extended, close the first two-position two-way cartridge valve (9) and open the first unloading valve (10). The hydraulic cylinder (5) retracts under the action of the reset spring. After a preset delay time, close the second two-position two-way cartridge valve (11) and open the second unloading valve (12). When the oil output by the hydraulic pump (3) is unloaded at low pressure and returned to the oil tank (1) through the second unloading valve (12), step 4 is executed again.

10. The control method according to claim 9, characterized in that, The preset delay time in step 5 is determined based on the filling time of the accumulator (13), and the formula is: T=K×t c +Δt (1); Where T is the preset delay time, t c The actual filling time for the accumulator (13) to be charged from the initial pressure to the set pressure; K is the compensation coefficient; Δ is the response time.

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