Hydraulic machine based on double potential energy coupling driving and active vibration suppression and control method thereof

Abstract

The present application relates to the field of hydraulic machine, provide based on double potential energy coupling drive and active vibration suppression hydraulic machine and its control method, including main hydraulic cylinder, slider, servo pump control unit, high pressure accumulator, low pressure oil supplement accumulator, wherein the lower end of the piston of main hydraulic cylinder is connected with slider, the upper end of the piston is opened with upper cavity, the side is opened with lower cavity, the inside of the piston is opened with vibration suppression cavity, the oil port of servo pump control unit is connected with high pressure accumulator, low pressure oil supplement accumulator is connected with lower cavity, the oil port of servo pump control unit is connected with upper cavity and lower cavity respectively, high pressure accumulator is also connected with vibration suppression cavity, servo pump control unit is used to control the flow direction of hydraulic oil, high pressure accumulator is used to provide high pressure hydraulic oil, low pressure oil supplement accumulator is used to pressure recovery, upper cavity and lower cavity are used for the piston lifting of main hydraulic cylinder, vibration suppression cavity is used for the damping of main hydraulic cylinder, main hydraulic cylinder and slider are used to complete pressurization, the present application can inhibit the vibration of hydraulic machine.

Description

Technical Field

[0001] This invention relates to the field of hydraulic press technology, and in particular to a hydraulic press and its control method based on dual potential energy coupling drive and active vibration suppression. Background Technology

[0002] Hydraulic presses are indispensable forming equipment in modern industry. With the development of modern industry, the production of workpieces demands "high frequency, fast response, and high precision." Traditional hydraulic presses mainly suffer from the following problems: 1. High energy consumption and low efficiency: Traditional valve control systems mainly rely on throttling speed regulation, resulting in large overflow losses; the gravitational potential energy generated by the frequent up and down movement of the slider and the elastic potential energy after pressurization are mostly dissipated in the form of heat energy.

[0003] 2. High installed power: To meet the peak power requirements of instantaneous acceleration and high-pressure molding, it is often necessary to equip high-power motors and large pump stations, resulting in a large impact on the power grid.

[0004] 3. Hydraulic shock and vibration: Under high pressure and high frequency pressing conditions, due to the compressibility of the oil and the huge inertial force, a violent "water hammer effect" and mechanical vibration will be generated at the moment of reversal. This not only affects the precision of the parts, but also easily leads to pipeline rupture and seal failure.

[0005] 4. Lack of adaptive control parameters: The vibration suppression parameters of existing servo pump control systems are mostly fixed values, which cannot adapt to the drift of system characteristics caused by different molding processes, oil temperature changes and equipment wear. After long-term use, the vibration suppression effect will decrease significantly.

[0006] Existing solutions often use servo pump control instead of valve control. While this solves some energy-saving problems, when dealing with high-frequency commutation impacts and large-tonnage inertial loads, relying solely on the dynamic response of the motor often results in lag, and there is a lack of effective mechanical-hydraulic coupling vibration suppression methods. Summary of the Invention

[0007] This invention aims to at least solve one of the technical problems existing in related technologies. To this end, this invention provides a hydraulic press and its control method based on dual potential energy coupling drive and active vibration suppression, effectively reducing the mechanical vibration of the hydraulic press during operation.

[0008] This invention provides a hydraulic press based on dual potential energy coupling drive and active vibration suppression, including a main hydraulic cylinder, a slider, a servo pump control unit, a high-pressure accumulator, and a low-pressure replenishing accumulator; wherein, in the main hydraulic cylinder, the lower end of the piston of the main hydraulic cylinder is connected to the slider, the upper end of the piston has an upper cavity, the side has a lower cavity, and the piston has a vibration suppression cavity inside. The oil port of the servo pump control unit is connected to the high-pressure accumulator, the low-pressure replenishing oil accumulator is connected to the lower cavity, the oil port of the servo pump control unit is connected to the upper cavity and the lower cavity respectively, and the high-pressure accumulator is also connected to the vibration damping cavity. The servo pump control unit controls the flow of hydraulic oil, the high-pressure accumulator provides high-pressure hydraulic oil, the low-pressure replenishment accumulator recovers pressure, the upper and lower chambers are used for piston lifting and lowering of the main hydraulic cylinder, the vibration damping chamber reduces vibration of the main hydraulic cylinder, and the main hydraulic cylinder and slider are used to pressurize.

[0009] According to the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, the servo pump control unit includes a servo motor and a bidirectional quantitative piston pump. The servo motor and the bidirectional quantitative piston pump are connected. The oil port of the bidirectional quantitative piston pump is connected to a high-pressure accumulator. The oil port of the bidirectional quantitative piston pump is also connected to the upper cavity and the lower cavity respectively.

[0010] According to the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, the effective area ratio of the vibration suppression cavity to the upper cavity is 0.05~0.1.

[0011] According to the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, two isolation sealing layers are provided between the upper cavity and the vibration suppression cavity, and a leakage monitoring groove is opened between the isolation sealing layers, and a low pressure sensor is installed in the leakage monitoring groove.

[0012] This invention provides a control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression, comprising: S1: Causes the slider to fall and obtains the slider's movement speed. When the slider's movement speed increases, the bidirectional quantitative piston pump of the servo pump control unit draws the hydraulic oil in the lower chamber into the upper chamber. At the same time, the excess hydraulic oil discharged from the lower chamber enters the low-pressure replenishing accumulator. S2: Obtain the slider approach distance and determine the distance threshold. When the slider approach distance is less than the distance threshold, the high-pressure accumulator injects high-pressure hydraulic oil into the upper cavity. S3: Listen for pre-pressure relief command. When the slider is stationary and the pre-pressure relief command is received, determine the first target pressure, calculate the high pressure injection amount based on the first target pressure, and inject high pressure hydraulic oil into the vibration damping chamber according to the high pressure injection amount. S4: Obtain the pressure parameters of the upper cavity, generate an active vibration damping signal based on the pressure parameters of the upper cavity, calculate the vibration damping gain coefficient after receiving the active vibration damping signal, calculate the second target pressure based on the vibration damping gain coefficient, and inject high-pressure hydraulic oil into the vibration damping cavity according to the second target pressure. S5: Make the slider rise and obtain the slider return speed. Calculate the third target pressure based on the slider return speed. The high-pressure accumulator injects high-pressure hydraulic oil into the vibration damping chamber based on the third target pressure. S6: Generate a vibration suppression and pressure relief signal based on the third target pressure and the slider approach distance. After receiving the vibration suppression and pressure relief signal, the high-pressure accumulator will return the high-pressure hydraulic oil in the vibration suppression chamber to the high-pressure accumulator until the high-pressure hydraulic oil is completely recovered, thus completing the control of the hydraulic press.

[0013] According to the control method of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, in step S3, the pre-pressure relief duration is determined by the issuance time of the pre-pressure relief command, and the high pressure injection amount is calculated based on the first target pressure and the pre-pressure relief duration.

[0014] According to the control method of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, in step S4, a pressure relief speed threshold is determined. When the pressure parameter of the upper cavity continues to decrease and the rate of decrease of the pressure parameter of the upper cavity exceeds the pressure relief speed threshold, the active vibration suppression signal is generated.

[0015] According to the control method of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, in step S4, the vibration suppression gain coefficient includes a first vibration suppression gain coefficient and a second vibration suppression gain coefficient. The pressure relief amplitude of the upper cavity pressure parameter is determined, the first vibration suppression gain coefficient is calculated according to the pressure relief amplitude, the equivalent damping coefficient of the hydraulic press is calculated, and the second vibration suppression gain coefficient is calculated according to the equivalent damping coefficient of the hydraulic press.

[0016] According to the control method of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, in step S5, the bidirectional quantitative piston pump of the servo pump control unit draws the hydraulic oil in the upper cavity into the lower cavity, and at the same time, the low-pressure oil replenishment accumulator injects low-pressure hydraulic oil into the lower cavity, causing the slider to rise.

[0017] According to the control method of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention, in step S6, the maximum value of the slider approach distance and the third target pressure threshold are determined. When the slider approach distance reaches the maximum value of the slider approach distance or the third target pressure is less than the third target pressure threshold, the vibration suppression and pressure relief signal is generated.

[0018] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: This invention provides a hydraulic press and its control method based on dual potential energy coupling drive and active vibration suppression. By creating a vibration suppression chamber inside the piston and injecting high-pressure hydraulic oil into the chamber in stages and in a quantitative manner, the water hammer effect during operation and vibration during pressure relief can be effectively suppressed, thereby protecting the main frame and piping system and significantly reducing equipment maintenance costs. Furthermore, compared to using a motor to suppress vibration, the instantaneous release of hydraulic potential energy can overcome the lag in acceleration time of a servo motor, significantly increasing the pressing frequency. The controller can also adjust the vibration suppression gain coefficient online based on measured data, thereby regulating the injection amount of high-pressure hydraulic oil and improving the vibration suppression effect.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention.

[0022] Figure 2 This is a schematic diagram of the main hydraulic cylinder of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention.

[0023] Figure 3 This is a schematic diagram of the upper cavity pressure and the damping force of the damping cavity of the hydraulic press based on dual potential energy coupling drive and active vibration damping provided by the present invention.

[0024] Figure label: 1. Main hydraulic cylinder; 2. Slider; 3. Servo motor; 4. Bidirectional quantitative piston pump; 5. High-pressure accumulator; 6. Low-pressure replenishing accumulator; 7. High-pressure valve of vibration damping chamber; 8. High-pressure valve of upper chamber; 9. Low-pressure valve; 101. Piston; 102. Vibration damping chamber; 103. Upper chamber; 104. Lower chamber. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but cannot be used to limit the scope of this invention.

[0026] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0028] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] The following is combined Figures 1 to 3 Specific embodiments of the present invention are described below. Figure 1 The schematic diagram of the hydraulic press based on dual potential energy coupling drive and active vibration suppression provided by the present invention includes a main hydraulic cylinder 1, a slider 2, a servo pump control unit, a high-pressure accumulator 5, and a low-pressure replenishing accumulator 6. In the main hydraulic cylinder 1, the lower end of the piston 101 is connected to the slider 2. The upper end of the piston 101 has an upper cavity 103, and the side has a lower cavity 104. The lower cavity 104 surrounds the piston 101, and the piston top of the piston 101 separates the upper cavity 103 and the lower cavity 104. A vibration suppression cavity 102 is also provided inside the piston 101, and the effective area ratio of the vibration suppression cavity 102 to the upper cavity 103 is 0.05~0.1. The specific structure of the main hydraulic cylinder 1 is as follows: Figure 2 As shown, The vibration damping chamber 102 is located at the center of the piston 101 and is formed by inserting a hollow plunger into a blind hole at the center of the piston 101. The hollow plunger and the piston 101 are precisely fitted together, with a combination of lip seal and dustproof seal. The servo pump control unit includes a servo motor 3 and a bidirectional quantitative plunger pump 4. The servo pump control unit is used to control the flow direction of hydraulic oil. The high-pressure accumulator 5 is used to provide high-pressure hydraulic oil, and the low-pressure replenishment accumulator 6 is used for pressure recovery. The upper chamber 103 and the lower chamber 104 are used for the lifting and lowering of the piston 101 of the main hydraulic cylinder 1. The vibration damping chamber 102 is used to dampen the vibration of the main hydraulic cylinder 1. The main hydraulic cylinder 1 and the slider 2 are used to perform the pressurization of the workpiece.

[0031] The servo pump control unit, used to control the flow of hydraulic oil, has its oil port connected to the high-pressure accumulator 5 via the upper chamber high-pressure valve 8. The oil ports of the servo pump control unit are connected to the upper chamber 103 and the lower chamber 104 respectively. The high-pressure accumulator 5 is also connected to the vibration damping chamber 102 via the vibration damping chamber high-pressure valve 7. The low-pressure replenishing accumulator 6 is connected to the lower chamber 104 via the low-pressure valve 9. Specifically, the servo motor 3 is connected to the bidirectional quantitative plunger pump 4. The oil port of the bidirectional quantitative plunger pump 4 is connected to the high-pressure accumulator 5 via the upper chamber high-pressure valve 8. The oil ports of the bidirectional quantitative plunger pump 4 are also connected to the upper chamber 103 and the lower chamber 104 respectively. In this embodiment, the pre-charge nitrogen pressure of the high-pressure accumulator 5 is 60% of the working pressure, and the pre-charge pressure of the low-pressure replenishing accumulator 6 is approximately 3MPa to 5MPa.

[0032] In addition, two isolation sealing layers are provided between the upper cavity 103 and the vibration damping cavity 102, and a leakage monitoring groove is formed between the isolation sealing layers. A low-pressure sensor is installed in the leakage monitoring groove. In this way, when one isolation sealing layer fails, high-pressure hydraulic oil will enter the leakage monitoring groove and be detected by the low-pressure sensor. At this time, the low-pressure sensor will issue a fault alarm, thereby taking measures to prevent high-pressure hydraulic oil in the upper cavity 103 from entering the vibration damping cavity 102 and causing an accident.

[0033] Furthermore, this invention also provides a control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression, which is used to control the aforementioned hydraulic press based on dual potential energy coupling drive and active vibration suppression, including: S1: Causes the slider to fall and obtains the slider's movement speed. When the slider's movement speed increases, the bidirectional quantitative piston pump of the servo pump control unit draws the hydraulic oil in the lower chamber into the upper chamber. At the same time, the excess hydraulic oil discharged from the lower chamber enters the low-pressure replenishing accumulator. Furthermore, to complete the operation of applying pressure to the workpiece by the hydraulic press, it is first necessary to release the lock on piston 101 and slider 2, allowing slider 2 to begin moving downwards due to gravity. At this time, the slider speed needs to be continuously monitored. As the slider speed increases, to accelerate the descent of slider 2, the bidirectional quantitative piston pump 4 of the servo pump control unit continuously draws hydraulic oil from the lower chamber 104 and injects it into the upper chamber 103. As the hydraulic oil in the upper chamber 103 increases and the hydraulic oil in the lower chamber 104 decreases, the descent speed of slider 2 increases significantly. At this time, the vibration damping chamber 102 is in a floating zero-pressure state, generating no additional resistance. In addition, the excess hydraulic oil discharged from the lower chamber 104 enters the low-pressure oil replenishment accumulator 6 to convert gravitational potential energy into hydraulic energy, which is then stored as low-pressure hydraulic oil. This process continues until slider 2 falls to the predetermined position and is about to contact the workpiece.

[0034] S2: Obtain the slider approach distance and determine the distance threshold. When the slider approach distance is less than the distance threshold, the high-pressure accumulator injects high-pressure hydraulic oil into the upper cavity. Furthermore, it is necessary to continuously obtain the distance between slider 2 and the workpiece, that is, the slider approach distance, and also to determine a very small distance threshold. When the slider approach distance is about to be less than the distance threshold, the servo motor 3 begins to decelerate, and when it is less than the distance threshold and touches the workpiece, that is, when the motor torque of the servo motor 3 reaches the preset rated value, the high-pressure valve 8 of the upper cavity opens, and the high-pressure accumulator 5 begins to inject high-pressure hydraulic oil into the upper cavity 103 through the drive of the bidirectional quantitative plunger pump 4. This allows the system to apply huge pressure in a very short time, without the need for a high-torque motor, and relatively saves energy.

[0035] S3: Listen for pre-pressure relief command. When the slider is stationary and the pre-pressure relief command is received, determine the first target pressure, calculate the high pressure injection amount based on the first target pressure, and inject high pressure hydraulic oil into the vibration damping chamber according to the high pressure injection amount. Furthermore, the purpose of this stage is to calculate the high-pressure injection amount, so that the high-pressure accumulator can inject high-pressure hydraulic oil into the vibration damping chamber according to the high-pressure injection amount. Specifically, in step S3, the pre-depressurization duration is determined by the issuance time of the pre-depressurization command, and the high-pressure injection amount is calculated based on the first target pressure and the pre-depressurization duration.

[0036] The specific implementation method for the above steps in this embodiment is as follows: After the pressure is applied, the hydraulic press needs to release pressure to lift the slider 2. At this time, a huge amount of high-pressure elastic potential energy accumulates in the upper cavity 103. The traditional approach is to directly release pressure or release pressure proportionally, which will lead to vibration and prolonged cycle time. Therefore, vibration can be avoided by providing damping force through the vibration damping cavity 102. According to the dynamic pressure equation of the vibration damping cavity 102, due to the large hydraulic stiffness of the cavity and the small volume of the vibration damping cavity 102, a very small net injection oil volume can produce a large pressure change. Overshoot must be prevented through staged closed-loop control. For this reason, it is necessary to listen for the pre-depressurization command. That is, when 10ms~30ms before depressurization, the controller will issue a pre-depressurization command. When the slider 2 is stationary and the controller receives the pre-depressurization command, the duration of the pre-depressurization needs to be determined by how long before the subsequent depressurization command is issued. In addition, it is necessary to determine the first target pressure within the vibration damping cavity 102. This allows for the calculation of the high-pressure injection volume. : in, The volume within the vibration damping cavity 102, This is the bulk elastic modulus of the oil. Thus, the high-pressure accumulator 5 injects high-pressure hydraulic oil into the vibration damping chamber 102 through the high-pressure valve 7 according to the high-pressure injection amount, allowing the vibration damping chamber 102 to pre-accumulate energy, thereby reducing the time required for pressure release.

[0037] S4: Obtain the pressure parameters of the upper cavity, generate an active vibration damping signal based on the pressure parameters of the upper cavity, calculate the vibration damping gain coefficient after receiving the active vibration damping signal, calculate the second target pressure based on the vibration damping gain coefficient, and inject high-pressure hydraulic oil into the vibration damping cavity according to the second target pressure. Furthermore, the purpose of this stage is to calculate the vibration suppression gain coefficient, thereby calculating the second injection amount. The high-pressure accumulator injects high-pressure hydraulic oil into the vibration suppression chamber according to the second target pressure. Specifically, in step S4, a pressure relief speed threshold is determined. When the pressure parameter of the upper chamber continues to decrease, and the rate of decrease of the pressure parameter of the upper chamber exceeds the pressure relief speed threshold, the active vibration suppression signal is generated.

[0038] In step S4, the vibration suppression gain coefficient includes a first vibration suppression gain coefficient and a second vibration suppression gain coefficient. The pressure relief amplitude of the upper cavity pressure parameter is determined, the first vibration suppression gain coefficient is calculated based on the pressure relief amplitude, the equivalent damping coefficient of the hydraulic press is calculated, and the second vibration suppression gain coefficient is calculated based on the equivalent damping coefficient of the hydraulic press.

[0039] The specific implementation method in this embodiment is as follows, based on the above steps. Here, it is necessary to continuously monitor the pressure inside the upper cavity 103, i.e., the upper cavity pressure parameter. As the pressure relief command is issued and the pressure relief proceeds, the pressure inside the upper cavity 103 will continuously decrease. When the absolute value of the rate of change of pressure inside the upper cavity 103 is greater than the preset pressure relief rate threshold, and the upper cavity pressure parameter continues to decrease, the controller needs to generate an active vibration suppression signal. After the active suppression signal is received by the controller, since the vibration suppression cavity 102 needs to provide an equal reverse impulse within the predetermined pressure relief time, it is assumed that the pressure in the upper cavity 103 decreases linearly. The pressure relief amplitude of the upper cavity pressure parameter per unit time is determined. Then the first vibration suppression gain coefficient can be calculated. : in, This is the preset impulse cancellation coefficient. The effective area of ​​the upper cavity 103, Let d represent the effective area of ​​the vibration damping cavity 102, d denote the differential, and t represent time. These are the pressure parameters for the upper cavity.

[0040] Next, the hydraulic stiffness of the system needs to be calculated: in, Let be the volume of the upper cavity 103. Determine the target damping ratio ζ of the hydraulic press, and then calculate the equivalent damping coefficient of the hydraulic press: Where M is the total mass of the moving parts. This allows us to calculate the second vibration damping gain coefficient: in, This is the system's inherent frequency.

[0041] The second target pressure can then be calculated based on the first target pressure and the vibration damping gain coefficient. : + High-pressure accumulator 5 injects high-pressure hydraulic oil into vibration damping chamber 102 to maintain the second target pressure in the chamber, thus providing damping force and reducing vibration during pressure relief. Furthermore, the first damping gain coefficient can be continuously adjusted; that is, the difference between the current vibration acceleration of the hydraulic press and the preset target acceleration is continuously calculated and finely adjusted step by step to make the current vibration acceleration of the hydraulic press continuously approach the target acceleration, thereby further improving the vibration reduction effect.

[0042] S5: Make the slider rise and obtain the slider return speed. Calculate the third target pressure based on the slider return speed. The high-pressure accumulator injects high-pressure hydraulic oil into the vibration damping chamber based on the third target pressure. Furthermore, the purpose of this stage is to calculate the third target pressure, thereby injecting high-pressure hydraulic oil into the vibration damping chamber. Specifically, in step S5, the bidirectional quantitative piston pump of the servo pump control unit draws hydraulic oil from the upper chamber into the lower chamber, while the low-pressure oil replenishment accumulator injects low-pressure hydraulic oil into the lower chamber, causing the slider to rise.

[0043] The specific implementation method for the above steps in this embodiment is as follows: After depressurization for a period of time, the slider 2 can be raised. In order for the slider 2 to rise back, the bidirectional quantitative piston pump 4 of the servo pump control unit needs to draw the hydraulic oil in the upper chamber 103 into the lower chamber 104. At the same time, the low-pressure oil replenishment accumulator 6 also needs to inject the excess low-pressure hydraulic oil that was previously recovered back into the lower chamber 104 through the low-pressure valve 9, so that the slider 2 rises back.

[0044] When slider 2 rises, it is necessary to obtain the slider return speed at time t. The third target pressure is calculated based on the slider return speed. : in, The preset maximum slider return speed, The second target pressure is the pressure at which slider 2 begins to rise. To maintain the third target pressure, high-pressure hydraulic oil is injected into the vibration damping chamber 102 by the high-pressure accumulator 5, thus completing the vibration reduction during the rising process.

[0045] S6: Generate a vibration suppression and pressure relief signal based on the third target pressure and the slider approach distance. After receiving the vibration suppression and pressure relief signal, the high-pressure accumulator will return the high-pressure hydraulic oil in the vibration suppression chamber to the high-pressure accumulator until the high-pressure hydraulic oil is completely recovered, thus completing the control of the hydraulic press.

[0046] Furthermore, the purpose of this stage is to recover the high-pressure hydraulic oil in the vibration damping chamber to the high-pressure accumulator and to cause the slider to return, thus completing the control of the hydraulic press. Specifically, in step S6, the maximum slider approach distance and the third target pressure threshold are determined. When the slider approach distance reaches the maximum slider approach distance or the third target pressure is less than the third target pressure threshold, the vibration damping and pressure relief signal is generated.

[0047] The specific implementation method for the above steps in this embodiment is as follows: First, the maximum slider approach distance and the third target pressure threshold need to be determined. Then, the slider approach distance and the third target pressure are continuously acquired. As the slider rises, the third target pressure decreases, and the slider approach distance increases. When the slider approach distance reaches its maximum value or the third target pressure is less than the third target pressure threshold, vibration damping is no longer needed. At this point, the high-pressure accumulator 5 recycles the high-pressure hydraulic oil in the vibration damping chamber 102 back into the high-pressure accumulator 5 until all the high-pressure hydraulic oil is recycled, and the slider 2 returns to its original position to await the next operation, thus completing the control of the hydraulic press. The changes in the pressure in the chamber and the damping force in the vibration damping chamber are as follows: Figure 3 As shown, Figure 3 The vertical axis represents pressure or force. When applied to the upper cavity 103, it represents pressure in megapascals, and when applied to the vibration damping cavity 102, it represents force in meganewtons. The horizontal axis represents time in seconds. The bulge in the vibration damping cavity 102 indicated by the arrow means that the vibration damping cavity 102 begins to dampen vibration when the pressure in the upper cavity 103 is released, which is active vibration damping intervention.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulic press based on dual potential energy coupling drive and active vibration suppression, characterized in that, It includes a main hydraulic cylinder, a slider, a servo pump control unit, a high-pressure accumulator, and a low-pressure replenishing accumulator; wherein, in the main hydraulic cylinder, the lower end of the piston of the main hydraulic cylinder is connected to the slider, the upper end of the piston has an upper cavity, the side has a lower cavity, and the piston has a vibration damping cavity inside. The oil port of the servo pump control unit is connected to the high-pressure accumulator, the low-pressure replenishing oil accumulator is connected to the lower cavity, the oil port of the servo pump control unit is connected to the upper cavity and the lower cavity respectively, the high-pressure accumulator is also connected to the vibration damping cavity, and the high-pressure accumulator can inject high-pressure hydraulic oil into the vibration damping cavity to provide vibration damping force. Among them, the servo pump control unit is used to control the flow of hydraulic oil, the high-pressure accumulator is used to provide high-pressure hydraulic oil, the low-pressure replenishment accumulator is used for pressure recovery, the upper and lower chambers are used for the piston lifting and lowering of the main hydraulic cylinder, the vibration damping chamber is used for vibration reduction when the upper chamber of the main hydraulic cylinder is depressurized, and the main hydraulic cylinder and slider are used to complete the pressurization. The effective area ratio of the vibration damping cavity to the upper cavity is 0.05~0.

1. Two isolation sealing layers are provided between the upper cavity and the vibration damping cavity. A leakage monitoring groove is opened between the isolation sealing layers, and a pressure sensor is installed in the leakage monitoring groove.

2. The hydraulic press based on dual potential energy coupling drive and active vibration suppression according to claim 1, characterized in that, The servo pump control unit includes a servo motor and a bidirectional quantitative plunger pump. The servo motor and the bidirectional quantitative plunger pump are connected. The oil port of the bidirectional quantitative plunger pump is connected to a high-pressure accumulator. The oil port of the bidirectional quantitative plunger pump is also connected to the upper chamber and the lower chamber, respectively.

3. A control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression, characterized in that, Controlling the hydraulic press based on dual potential energy coupling drive and active vibration suppression as described in any one of claims 1 to 2, comprising: S1: Causes the slider to fall and obtains the slider's movement speed. When the slider's movement speed increases, the bidirectional quantitative piston pump of the servo pump control unit draws the hydraulic oil in the lower chamber into the upper chamber. At the same time, the excess hydraulic oil discharged from the lower chamber enters the low-pressure replenishing accumulator. S2: Obtain the slider approach distance and determine the distance threshold. When the slider approach distance is less than the distance threshold, the high-pressure accumulator injects high-pressure hydraulic oil into the upper cavity. S3: Listen for the pre-decompression command. When the slider is stationary and the pre-decompression command is received, determine the first target pressure, calculate the high pressure injection amount based on the first target pressure, and inject high pressure hydraulic oil into the vibration damping chamber according to the high pressure injection amount. S4: Obtain the pressure parameters of the upper cavity, generate an active vibration damping signal based on the pressure parameters of the upper cavity, calculate the vibration damping gain coefficient after receiving the active vibration damping signal, calculate the second target pressure based on the vibration damping gain coefficient, and inject high-pressure hydraulic oil into the vibration damping cavity according to the second target pressure. S5: Make the slider rise and obtain the slider return speed. Calculate the third target pressure based on the slider return speed. The high-pressure accumulator injects high-pressure hydraulic oil into the vibration damping chamber based on the third target pressure. S6: Generate a vibration suppression and pressure relief signal based on the third target pressure and the slider approach distance. After receiving the vibration suppression and pressure relief signal, the high-pressure accumulator will return the high-pressure hydraulic oil in the vibration suppression chamber to the high-pressure accumulator until the high-pressure hydraulic oil is completely recovered, thus completing the control of the hydraulic press.

4. The control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression according to claim 3, characterized in that, In step S3, the pre-depressurization duration is determined by the issuance time of the pre-depressurization command, and the high-pressure injection amount is calculated based on the first target pressure and the pre-depressurization duration.

5. The control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression according to claim 3, characterized in that, In step S4, a pressure relief speed threshold is determined. When the pressure parameter of the upper cavity continues to decrease and the rate of decrease of the pressure parameter of the upper cavity exceeds the pressure relief speed threshold, the active vibration suppression signal is generated.

6. The control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression according to claim 3, characterized in that, In step S4, the vibration suppression gain coefficient includes a first vibration suppression gain coefficient and a second vibration suppression gain coefficient. The pressure relief amplitude of the upper cavity pressure parameter is determined, the first vibration suppression gain coefficient is calculated based on the pressure relief amplitude, the equivalent damping coefficient of the hydraulic press is calculated, and the second vibration suppression gain coefficient is calculated based on the equivalent damping coefficient of the hydraulic press.

7. The control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression according to claim 3, characterized in that, In step S5, the bidirectional quantitative piston pump of the servo pump control unit draws hydraulic oil from the upper chamber into the lower chamber, while the low-pressure oil replenishment accumulator injects low-pressure hydraulic oil into the lower chamber, causing the slider to rise.

8. The control method for a hydraulic press based on dual potential energy coupling drive and active vibration suppression according to claim 3, characterized in that, In step S6, the maximum slider approach distance and the third target pressure threshold are determined. When the slider approach distance reaches the maximum slider approach distance or the third target pressure is less than the third target pressure threshold, the vibration suppression and pressure relief signal is generated.

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