Multi-branch active pressure regulating device and regulating method applicable to gas accumulators

Abstract

This invention discloses a multi-branch active pressure regulating device and method for gas accumulators, comprising a bidirectional hydraulic pump, a working cylinder, a gas cylinder, a gas cylinder switch valve, and n accumulator switch valves. The liquid chamber of the working cylinder is connected to the bidirectional hydraulic pump, and the gas chamber of the working cylinder is connected to both the gas cylinder switch valve and the n accumulator switch valves. The gas cylinder switch valve is connected to the gas cylinder, and the n accumulator switch valves are connected one-to-one with the n accumulators. This invention enables stable charging pressure of the accumulator over a wide temperature range, ensuring consistency in oil storage and energy release processes, and ensuring that the load posture is unaffected by ambient temperature.

Description

Technical Field

[0001] This invention relates to the field of gas accumulators, specifically to a multi-branch active pressure regulating device and its regulating method. Background Technology

[0002] In hydraulic systems where there is a large instantaneous flow demand during operation but a small flow rate is sufficient during normal operation (such as hydraulic catapult systems), accumulators are often used as the power source for the entire system, and gas accumulators are frequently adopted due to their higher energy density. However, due to thermal expansion and contraction of compressed gas, the pre-charge gas pressure often changes significantly with temperature variations, affecting the consistency of energy storage and release processes and causing deviations in load operation.

[0003] Currently, the pressure regulation of gas accumulators mainly relies on passive charging and discharging or proportional valve control, which has drawbacks such as slow response speed, low pressure control accuracy, and inability to achieve gas recovery.

[0004] This invention achieves bidirectional gas exchange between the auxiliary gas cylinder and the controlled accumulator gas chamber by driving the change of the working cylinder volume and the logic control of the switching valve, thereby completing the pressure control of the accumulator gas chamber and realizing: millisecond-level dynamic response, pressure control accuracy of ±0.5% and gas recycling. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-branch active pressure regulation device suitable for gas accumulators, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A multi-branch active pressure regulating device suitable for gas accumulators is characterized by comprising a bidirectional hydraulic pump, a working cylinder, a gas cylinder, a gas cylinder switch valve, and n accumulator switch valves. The liquid chamber of the working cylinder is connected to the bidirectional hydraulic pump, and the gas chamber of the working cylinder is connected to the gas cylinder switch valve and the n accumulator switch valves respectively. The gas cylinder switch valve is connected to the gas cylinder, and the n accumulator switch valves are connected to the n accumulators in a one-to-one correspondence, where n is a positive integer.

[0007] Furthermore, the bidirectional hydraulic pump is driven by an electric motor.

[0008] Furthermore, a safety valve is connected next to the oil outlet of the bidirectional hydraulic pump.

[0009] Furthermore, it also includes an inflation valve, which is connected to an external air source and is used to inflate the gas cylinder and the gas chambers of the n accumulators.

[0010] Furthermore, the piston of the working cylinder is provided with limit switches at its extreme positions toward the liquid chamber and the gas chamber, respectively.

[0011] The present invention also provides a method for adjusting the multi-branch active pressure regulating device as described above, characterized in that it includes: When the pressure in the gas chamber of a certain accumulator is lower than the minimum set value, the accumulator enters the pressurization mode. In the first step, the piston of the working cylinder is moved to the liquid chamber side by the bidirectional hydraulic pump, and the pressurized gas in the gas cylinder is drawn into the gas chamber of the working cylinder. When the piston of the bidirectional hydraulic pump moves to the limit position towards the liquid chamber side, the second step is entered. The piston of the working cylinder is moved to the gas chamber side by the bidirectional hydraulic pump, and the pressurized gas in the gas chamber is discharged into the gas chamber of the accumulator. The first and second steps are repeated until the pressure in the gas chamber of the accumulator reaches the minimum set value. When the gas chamber pressure of a certain accumulator is higher than the maximum set value, the accumulator enters the decompression mode. In the first step, the piston of the working cylinder is moved to the liquid chamber side by the bidirectional hydraulic pump, and the pressurized gas in the gas chamber of the accumulator is drawn into the gas chamber of the working cylinder. When the piston of the bidirectional hydraulic pump moves to the limit position towards the liquid chamber side, the second step is initiated. The piston of the working cylinder is moved to the gas chamber side by the bidirectional hydraulic cylinder, and the pressurized gas in the gas chamber is discharged into the gas cylinder. The first and second steps are repeated until the gas chamber pressure of the accumulator is lower than the maximum set value.

[0012] Furthermore, the boosting mode specifically includes: The first step involves releasing the pressure in the working cylinder's hydraulic chamber using a bidirectional hydraulic pump, while simultaneously closing the accumulator switch valve corresponding to the accumulator. After a delay, the gas cylinder switch valve is opened, allowing pressurized gas from the gas cylinder to enter the working cylinder's air chamber. When the piston of the bidirectional hydraulic pump reaches its limit position towards the hydraulic chamber, the second step begins. The bidirectional hydraulic pump pressurizes the working cylinder's hydraulic chamber, reducing its air chamber volume. Simultaneously, the gas cylinder switch valve is closed, and after a delay, the accumulator switch valve corresponding to the accumulator is opened, allowing pressurized gas from the bidirectional hydraulic pump's air chamber to enter the accumulator's air chamber. This process continues until the piston of the bidirectional hydraulic pump reaches its limit position towards the air chamber. The first and second steps are then repeated until the accumulator's air chamber pressure reaches the set value.

[0013] Furthermore, the decompression mode specifically includes: The first step involves releasing the pressure in the working cylinder's liquid chamber using a bidirectional hydraulic pump, while simultaneously closing the accumulator switch valve corresponding to the accumulator. After a delay, the gas cylinder switch valve is opened, allowing pressurized gas from the accumulator to enter the working cylinder's gas chamber. When the working cylinder's piston reaches its limit position towards the liquid chamber, the second step begins. The bidirectional hydraulic pump pressurizes the working cylinder's liquid chamber, reducing its gas chamber volume. Simultaneously, the accumulator switch valve corresponding to the accumulator is closed, and after a delay, the gas cylinder switch valve is opened, allowing pressurized gas from the working cylinder's gas chamber to enter the gas cylinder. This process continues until the bidirectional hydraulic pump causes the working cylinder's piston to reach its limit position towards the gas chamber. The first and second steps are then repeated until the accumulator's gas chamber pressure reaches the set value.

[0014] Furthermore, it also includes pressurizing the accumulator after filling it with fluid, so that the pressure of the oil stored in the accumulator is higher than the pressure of the hydraulic system.

[0015] Furthermore, it also includes: gas exchange between the gas chambers of different accumulators.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1) It can achieve stable charging pressure of the accumulator over a wide temperature range, ensuring consistency in oil storage and energy release processes, so as to ensure that the load attitude is not affected by ambient temperature. 2) The interaction process of the working gas is realized in a closed system without the participation of external gas, and there is no need for water vapor filtration devices, etc. In addition, the gas in the gas cylinder has a certain pressure, which reduces the compression ratio of the working cylinder and makes the device structure more compact. 3) This invention can be used for pressure control of a single accumulator, or for independent pressure control of multiple accumulator branches; 4) This invention, through control command priority determination, can independently control the pressure of the accumulator in its non-operating state (non-charging state) without affecting its function and performance in the operating state (charging state). (For example, a conventional constant-pressure accumulator has only one pressure value and cannot charge.) Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a multi-branch active pressure regulating device for gas accumulators according to the present invention when connected to the accumulator.

[0018] In the diagram: 1. Motor; 2. Two-way hydraulic pump; 3. Working cylinder; 4. High-pressure gas cylinder; 5. Safety valve; 6. Gas cylinder switch valve; 7. Accumulator; 8. Accumulator switch valve; 9. Gas filling valve. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 A multi-branch active pressure regulating device suitable for gas accumulators includes a motor 1, a bidirectional hydraulic pump 2, a working cylinder 3 (including a gas chamber / piston / liquid chamber), a high-pressure gas cylinder 4, a safety valve 5, a gas cylinder switch valve 6 (gas cylinder passage), an accumulator switch valve 8, and a charging valve 9. The liquid chamber of the working cylinder 3 is connected to the bidirectional hydraulic pump 2, and the gas chamber of the working cylinder 3 is connected to the gas cylinder switch valve 6 and n accumulator switch valves 8 respectively. The gas cylinder switch valve 6 is connected to the high-pressure gas cylinder 4, and the n accumulator switch valves 8 are connected one-to-one with n accumulators 7. The bidirectional hydraulic pump 2 is driven by the motor 1, where n is a positive integer.

[0021] The bidirectional hydraulic pump 2 is a cartridge-type two-dimensional (2D) piston pump suitable for high-frequency reciprocating load-bearing starting conditions, but it is not limited to two-dimensional (2D) piston pumps; other bidirectional pumps may also be used.

[0022] The bidirectional hydraulic pump 2 has two oil ports. One oil port is connected to the oil tank and is called the "return port". The other oil port is connected to the hydraulic chamber of the working cylinder 3 and is called the "outlet port". For safety reasons, a safety valve is connected to the outlet port to limit the maximum pressure of the outlet port and prevent the outlet pressure from being too high.

[0023] There is a movable piston between the air chamber and the liquid chamber of the working cylinder 3. A magnet is installed on the piston. Non-contact limit switches are installed at both ends of the working cylinder. When the piston moves to the limit position, the limit switch feeds back a position signal, causing the controller to drive the motor 1 to rotate in the opposite direction, and the relevant switch valve control signals change synchronously.

[0024] It should be noted that the reverse signals of motor 1 and accumulator switching valve 8 can also be controlled without the use of limit switches. For example, the system can be controlled by a fixed frequency switching method, such as switching once per second, which can also drive the normal operation of the entire system.

[0025] Accumulator switch valve 8 is a two-position, two-way, zero-leakage pneumatic switch valve used to control the on / off state of the air circuit. Other types of control valves capable of controlling the on / off state of the control circuit can also be used. It is worth noting that the leakage of the control valve should be as small as possible. Although excessive leakage will not affect the system's functionality, it will greatly affect the system's performance.

[0026] The inflation valve 9 is used to pre-charge the gas in the auxiliary high-pressure gas cylinder 4 and each accumulator 7 chamber at room temperature, and the inflation pressure is detected by a pressure sensor. During inflation, the inflation valve 9 is connected to an external gas source, and the high-pressure gas cylinder 4 and the accumulator 7 chambers can be inflated one by one or simultaneously. When inflating one by one, the pre-control valve corresponding to the object being inflated is opened to inflate, and the pre-control valve is closed after the pre-charge pressure is reached. When inflating simultaneously, all pre-control valves are opened at the same time, and the pre-control valves are closed when the object being inflated reaches the set pressure, until all control valves are closed.

[0027] The present invention also provides a method for adjusting the multi-branch active pressure regulating device as described above, comprising: When the pressure in the gas chamber of a certain accumulator is lower than the minimum set value, the accumulator enters the pressurization mode. In the first step, the piston of the working cylinder is moved to the liquid chamber side by the bidirectional hydraulic cylinder, drawing the pressurized gas in the gas cylinder into the gas chamber of the working cylinder. When the piston of the bidirectional hydraulic pump moves to the limit position towards the liquid chamber side, the second step is initiated. The piston of the working cylinder is moved to the gas chamber side by the bidirectional hydraulic cylinder, discharging the pressurized gas in the gas chamber into the gas chamber of the accumulator. The first and second steps are repeated until the pressure in the gas chamber of the accumulator reaches the minimum set value.

[0028] Specifically, the first step involves releasing the pressure in the working cylinder's liquid chamber using a bidirectional hydraulic pump, simultaneously closing the accumulator switch valve corresponding to the accumulator, and after a delay, opening the gas cylinder switch valve to allow pressurized gas from the gas cylinder to enter the working cylinder's gas chamber. When the piston of the bidirectional hydraulic pump reaches its limit position towards the liquid chamber, the second step begins. The bidirectional hydraulic pump pressurizes the working cylinder's liquid chamber, reducing its gas chamber volume. Simultaneously, the gas cylinder switch valve closes, and after a delay, the accumulator switch valve corresponding to the accumulator opens, allowing pressurized gas from the bidirectional hydraulic pump's gas chamber to enter the accumulator's gas chamber. This process continues until the working cylinder's piston reaches its limit position towards the gas chamber, repeating steps one and two until the accumulator's gas chamber pressure reaches the set value. Each completion of steps one and two represents one transfer of gas from the gas cylinder to the working cylinder's gas chamber and then to the accumulator's gas chamber.

[0029] When the gas chamber pressure of a certain accumulator is higher than the maximum set value, the accumulator enters the decompression mode. In the first step, the piston of the working cylinder is moved to the liquid chamber side by the bidirectional hydraulic cylinder, and the pressurized gas in the gas chamber of the accumulator is drawn into the gas chamber of the working cylinder. When the piston of the bidirectional hydraulic pump moves to the limit position towards the liquid chamber side, the second step is initiated. The piston of the working cylinder is moved to the gas chamber side by the bidirectional hydraulic cylinder, and the pressurized gas in the gas chamber is discharged into the gas cylinder. The first and second steps are repeated until the gas chamber pressure of the accumulator is lower than the maximum set value.

[0030] Specifically, the first step involves releasing the pressure in the working cylinder's liquid chamber using a bidirectional hydraulic pump, simultaneously closing the accumulator switch valve corresponding to the accumulator, and after a delay, opening the gas cylinder switch valve to allow pressurized gas from the accumulator to enter the working cylinder's gas chamber. When the working cylinder's piston reaches its limit position in the liquid chamber, the second step begins. The bidirectional hydraulic pump pressurizes the working cylinder's liquid chamber, reducing its gas chamber volume. Simultaneously, the accumulator switch valve corresponding to the accumulator is closed, and after a delay, the gas cylinder switch valve is opened, allowing pressurized gas from the working cylinder's gas chamber to enter the gas cylinder. This process continues until the working cylinder's piston reaches its limit position in the gas chamber, and then steps one and two are repeated until the accumulator's gas chamber pressure reaches the maximum set value. Each completion of steps one and two represents one transfer of gas from the gas cylinder to the working cylinder's gas chamber and then to the accumulator's gas chamber.

[0031] This invention can also be used to pressurize an accumulator after filling, so that the pressure of the stored oil in the accumulator is higher than the pressure of the hydraulic system, thereby reducing the pressure requirements of the hydraulic system. For example, after a hydraulic system fills the accumulator to the maximum system pressure of 28 MPa, the filling valve is closed, and then the air chamber of the accumulator is filled with air, which can increase the pressure of the stored oil to 35 MPa.

[0032] This invention can also be used to pressurize a gas source. For example, if a gas cylinder stores 10MPa high-pressure gas and needs to fill a sealed cavity to 20MPa, the gas cylinder can be connected to the first outlet of this invention, and the sealed cavity can be connected to the second outlet. By controlling the reciprocating motion of the piston of the working cylinder and the logic control of the first and second switching valves, the gas cylinder storing 10MPa gas can be pressurized to 20MPa to fill the sealed cavity.

[0033] This invention can also be used to realize the interaction between different accumulator chambers. For example, when the pressure of the first accumulator is higher than the set value and the pressure of the second accumulator is lower than the set value, the gas can flow between the first accumulator chamber, the working cylinder chamber, and the second accumulator chamber directly without going through a gas cylinder by controlling the opening and closing state of the corresponding switch valve.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-branch active pressure regulating device suitable for gas accumulators, characterized in that, It includes a bidirectional hydraulic pump, a working cylinder, a gas cylinder, a gas cylinder switch valve, and n accumulator switch valves. The liquid chamber of the working cylinder is connected to the bidirectional hydraulic pump, and the gas chamber of the working cylinder is connected to the gas cylinder switch valve and the n accumulator switch valves respectively. The gas cylinder switch valve is connected to the gas cylinder, and the n accumulator switch valves are connected to the n accumulators in a one-to-one correspondence, where n is a positive integer.

2. The multi-branch active pressure regulating device for gas accumulators according to claim 1, characterized in that, The bidirectional hydraulic pump is driven by an electric motor.

3. The multi-branch active pressure regulating device for gas accumulators according to claim 1, characterized in that, A safety valve is connected next to the oil outlet of the bidirectional hydraulic pump.

4. The multi-branch active pressure regulating device for gas accumulators according to claim 1, characterized in that, It also includes an inflation valve, which is connected to an external air source and is used to inflate the gas cylinder and the gas chambers of the n accumulators.

5. A multi-branch active pressure regulating device for gas accumulators according to claim 1, characterized in that, The piston of the working cylinder is equipped with limit switches at its extreme positions towards the liquid chamber and towards the gas chamber.

6. A method for adjusting the multi-branch active pressure regulating device as described in any one of claims 1-5, characterized in that, include: When the pressure in the gas chamber of a certain accumulator is lower than the minimum set value, the accumulator enters the pressurization mode. In the first step, the piston of the working cylinder is moved to the liquid chamber side by the bidirectional hydraulic pump, and the pressurized gas in the gas cylinder is drawn into the gas chamber of the working cylinder. When the piston of the bidirectional hydraulic pump moves to the limit position towards the liquid chamber side, the second step is entered. The piston of the working cylinder is moved to the gas chamber side by the bidirectional hydraulic pump, and the pressurized gas in the gas chamber is discharged into the gas chamber of the accumulator. The first and second steps are repeated until the pressure in the gas chamber of the accumulator reaches the minimum set value. When the gas chamber pressure of a certain accumulator is higher than the maximum set value, the accumulator enters the decompression mode. In the first step, the piston of the working cylinder is moved to the liquid chamber side by the bidirectional hydraulic pump, and the pressurized gas in the gas chamber of the accumulator is drawn into the gas chamber of the working cylinder. When the piston of the bidirectional hydraulic pump moves to the limit position towards the liquid chamber side, the second step is initiated. The piston of the working cylinder is moved to the gas chamber side by the bidirectional hydraulic cylinder, and the pressurized gas in the gas chamber is discharged into the gas cylinder. The first and second steps are repeated until the gas chamber pressure of the accumulator is lower than the maximum set value.

7. The adjustment method according to claim 6, characterized in that, The boosting modes specifically include: The first step involves releasing the pressure in the working cylinder's hydraulic chamber using a bidirectional hydraulic pump, while simultaneously closing the accumulator switch valve corresponding to the accumulator. After a delay, the gas cylinder switch valve is opened, allowing pressurized gas from the gas cylinder to enter the working cylinder's air chamber. When the piston of the bidirectional hydraulic pump reaches its limit position towards the hydraulic chamber, the second step begins. The bidirectional hydraulic pump pressurizes the working cylinder's hydraulic chamber, reducing its air chamber volume. Simultaneously, the gas cylinder switch valve is closed, and after a delay, the accumulator switch valve corresponding to the accumulator is opened, allowing pressurized gas from the bidirectional hydraulic pump's air chamber to enter the accumulator's air chamber. This process continues until the piston of the bidirectional hydraulic pump reaches its limit position towards the air chamber. The first and second steps are then repeated until the accumulator's air chamber pressure reaches the set value.

8. The adjustment method according to claim 6, characterized in that, The decompression modes specifically include: The first step involves releasing the pressure in the working cylinder's liquid chamber using a bidirectional hydraulic pump, while simultaneously closing the accumulator switch valve corresponding to the accumulator. After a delay, the gas cylinder switch valve is opened, allowing pressurized gas from the accumulator to enter the working cylinder's gas chamber. When the working cylinder's piston reaches its limit position towards the liquid chamber, the second step begins. The bidirectional hydraulic pump pressurizes the working cylinder's liquid chamber, reducing its gas chamber volume. Simultaneously, the accumulator switch valve corresponding to the accumulator is closed, and after a delay, the gas cylinder switch valve is opened, allowing pressurized gas from the working cylinder's gas chamber to enter the gas cylinder. This process continues until the bidirectional hydraulic pump causes the working cylinder's piston to reach its limit position towards the gas chamber. The first and second steps are then repeated until the accumulator's gas chamber pressure reaches the set value.

9. The adjustment method according to claim 6, characterized in that, Also includes: After the accumulator is filled with liquid, it is pressurized so that the pressure of the oil stored in the accumulator is higher than the pressure of the hydraulic system.

10. The adjustment method according to claim 6, characterized in that, Also includes: Gas exchange is performed between the gas chambers of different accumulators.

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