Hydraulic control system for a cubic press

Abstract

The application discloses a hydraulic control system of a cubic press, which has a liquid filling synchronizer, and adopts a constant-volume type of supplying oil to six hinge beam oil cylinders by hydraulic oil, and is not influenced by the influences of different hydraulic cylinder dampings, different self gravities of piston positions, different lengths of hydraulic lines from a hydraulic station to the hinge beam oil cylinders, different numbers of elbows and viscosity changes caused by oil temperature on the liquid filling synchronization, so that the starting synchronization in the liquid filling step and the displacement amount of the liquid filling process are accurately controlled, and the cubic press has excellent synchronization, and many accidents or factors caused by poor synchronization are avoided.

Description

Technical Field

[0001] This invention belongs to the field of diamond synthesis equipment, specifically relating to a hydraulic control system for a six-sided top press. Background Technology

[0002] The "filling" and "overpressure" steps in the hydraulic control of the six-sided top press are crucial for its commissioning and operation. The filling step involves the low-pressure control system controlling six ultra-high-pressure cylinders to fill the six hinge beam cylinders from the "stop hammer position," synchronously compressing the composite block to 6-10 MPa. Then, the hydraulic system switches to ultra-high-pressure oil supply to compress the composite block to the final pressure. There are two ways to complete the "filling" step: one is with the ultra-high-pressure hydraulic control seven-way valve closed, preventing connection between the six cylinders; synchronization of filling is achieved by adjusting the speed control throttle valve and back pressure valve, commonly known as "non-connected filling"; the other is with the ultra-high-pressure hydraulic control seven-way valve connected to all six cylinders, commonly known as "connected filling." In this case, the low-pressure system's speed control throttle valve is largely ineffective, while the back pressure valve in the front chamber may function. The most crucial step in this process is ensuring that the six jacks of the six-sided press compress the composite block to a given synchronous size. Adjusting this synchronous compression is a critical adjustment process, achieved by modifying the speed control valves and balance valves in the front and rear chambers of each cylinder. The "overpressure" step involves the ultra-high pressure section of the hydraulic system simultaneously supplying ultra-high pressure hydraulic fluid to the six hinged beam cylinders via an interconnected ultra-high pressure hydraulic control seven-way valve, compressing the composite block to the ultra-high pressure composite pressure. Because the six cylinders are connected during the ultra-high pressure stage, individual cylinder compression displacement cannot be controlled. Only during the "filling" step can the compression displacement of the composite block in three directions be adjusted, ensuring that the compression dimension error in the three directions of the composite block is generally within ±0.1mm when the composite pressure is reached. A commonly used six-sided press hydraulic system is shown in the appendix. Figure 1 .

[0003] The current shortcomings of the hydraulic system for the six-sided top press in controlling the "filling" step are as follows: Regardless of whether "non-connected filling" or "connected filling" is used, the spatial positions of the six hinge beam cylinders are different, the piston damping of each cylinder is different, the length of the pipeline from the hydraulic station to each cylinder is different, the spatial positions of the cylinders cause different gravity, and the hydraulic oil viscosity changes due to oil temperature, etc. After the "filling" command is issued, the six cylinders do not start simultaneously, causing a starting error of up to 1 second, resulting in asynchronous starting. Furthermore, when the six cylinders begin to move forward to reach the set filling pressure, the movement speed of each cylinder has a significant error, generally reaching 1-2 mm. During this stage, under the traditional flow control state of the speed regulating valve and back pressure valve, true synchronous filling cannot be achieved. This is the most serious and widespread problem existing in the current six-sided top press hydraulic system. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to provide a hydraulic control system for a six-sided top press. This system adds a constant-volume synchronous filling control to the low-pressure control section of the currently common six-sided top hydraulic system in the industry. This achieves precise control of the starting synchronization of the filling step and the filling displacement during the filling process, giving the six-sided top press excellent synchronization and effectively preventing many accidents or factors caused by poor synchronization.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A hydraulic control system for a six-sided top press includes a low-pressure control section, a high-pressure control section, and a pump unit. The low-pressure control section includes six ultra-high-pressure hydraulic control check valves, a first and second-position four-way directional valve, and a throttle valve. The ultra-high-pressure hydraulic control check valves serve as the boundary and isolation between the low-pressure and high-pressure sections. The low-pressure ends of the six ultra-high-pressure hydraulic control check valves are respectively connected in series with the first and second-position four-way directional valve and the throttle valve. The T port of the first and second-position four-way directional valve is connected to the return oil system pipeline. The six throttle valves are connected in parallel and then connected to the A port of the first three-position four-way directional valve. The P port of the first three-position four-way directional valve is connected to the pump unit system pressure. Hydraulic control check valves are connected in series between the low-pressure ends of the six ultra-high-pressure hydraulic control check valves and the A port of the first and second-position four-way directional valve, or between the P port of the first and second-position four-way directional valve and the throttle valve, or below the throttle valve. A filling synchronizer is connected to the upper end of the hydraulic control check valve through a three-way bypass. The filling synchronizer is connected to the second three-position four-way directional valve.

[0007] Preferably, the liquid filling synchronizer includes a beam and six liquid filling cylinders. The beam includes an upper crossbeam, a support column, and a lower crossbeam. The support column is vertically fixed between the two crossbeams. The movable crossbeam is slidably mounted on the support column. The liquid filling cylinders are mounted downwards on the upper crossbeam, and the piston rod of the liquid filling cylinder is fixedly connected to the movable crossbeam.

[0008] Furthermore, the hydraulic control check valve is connected in series below the throttle valve; the rear chamber of the filling cylinder is connected between the corresponding throttle valve and the hydraulic control check valve, and the front chamber of the filling cylinder is connected together by a hydraulic pipeline and then connected to the A port of the second three-position four-way directional valve. The P port of the second three-position four-way directional valve is connected to the pump group system pressure, and the T port is connected to the oil tank circuit.

[0009] Preferably, the liquid filling synchronizer includes a drive cylinder and six liquid filling cylinders. The drive cylinder includes a cylinder body, a front cylinder cover, and a drive piston. The front cylinder cover is installed at the opening of the cylinder body, and the drive piston is movably disposed in the cylinder body. The liquid filling cylinder is installed on the front cylinder cover, and the piston rod of the liquid filling cylinder extends into the cylinder body and is fixedly connected to the drive piston.

[0010] Furthermore, the hydraulic control check valve is connected in series between the throttle valve and the first two-position four-way directional valve; the rear chamber of the filling cylinder is connected between the corresponding first two-position four-way directional valve and the hydraulic control check valve, and the inner chamber of the driving cylinder is connected to the A port of the second three-position four-way directional valve. The P port of the second three-position four-way directional valve is connected to the pump group system pressure, and the T port is connected to the oil tank circuit.

[0011] Preferably, a drive cylinder is installed on the lower crossbeam, and the piston rod of the drive cylinder is fixed upward to the movable crossbeam.

[0012] Furthermore, the hydraulic control check valve is connected between the low-pressure end of the six ultra-high pressure hydraulic control check valves and the A port of the first two-position four-way directional valve; the rear chamber of the filling cylinder is connected in series with the first check valve and then connected between the corresponding ultra-high pressure hydraulic control check valve and the hydraulic control check valve; the rear chamber of the driving cylinder is connected to the A port of the second three-position four-way directional valve, the B port of the second three-position four-way directional valve is connected to the front chamber of the driving cylinder, the P port is connected to the pump system pressure, and the T port is connected to the oil tank circuit.

[0013] Furthermore, the rear chamber of the filling cylinder is provided with a second one-way valve that connects to the oil tank, and the front chamber of the filling cylinder is provided with a passage that connects to the oil tank.

[0014] Furthermore, a two-position two-way directional valve is connected in parallel to the second check valve.

[0015] Furthermore, the filling synchronizer is also equipped with a displacement sensor for detecting the displacement of the filling cylinder.

[0016] The beneficial effects of this invention are as follows:

[0017] The hydraulic system of the six-sided top press proposed in this invention has a filling synchronizer. It uses a constant-volume hydraulic oil supply to the six hinge beam cylinders, which is not affected by the different damping of the hydraulic cylinders, the different piston positions, the length and number of bends of the hydraulic pipeline from the hydraulic station to the hinge beam cylinders, or the viscosity changes caused by oil temperature. This achieves precise control of the starting synchronization of the filling step and the filling displacement during the filling process, giving the six-sided top press excellent synchronization and eliminating many accidents or factors caused by poor synchronization. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a prior art six-sided hydraulic system;

[0019] Figure 2 This is a schematic diagram of the liquid filling synchronizer of Embodiment 1 of the present invention;

[0020] Figure 3 for Figure 1 A cross-sectional view of the structure;

[0021] Figure 4 This is a schematic diagram of the hydraulic control system of Embodiment 1 of the present invention;

[0022] Figure 5 This is a schematic diagram of the liquid filling synchronizer of Embodiment 2 of the present invention;

[0023] Figure 6 for Figure 4 A cross-sectional view of the structure;

[0024] Figure 7 This is a schematic diagram of the hydraulic control system of Embodiment 2 of the present invention;

[0025] Figure 8 This is a schematic diagram of the liquid filling synchronizer of Embodiment 3 of the present invention;

[0026] Figure 9 for Figure 7 A cross-sectional view of the structure;

[0027] Figure 10 This is a schematic diagram of the hydraulic control system in Embodiment 3 of the present invention. Detailed Implementation

[0028] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention.

[0029] Example 1:

[0030] like Figure 2-3 As shown, this invention proposes a liquid-filling synchronizer, which includes a beam and six liquid-filling cylinders 14 of equal diameter. The beam includes an upper crossbeam 11, a support column 15, and a lower crossbeam 12. At least two support columns 15 are provided and vertically fixed between two crossbeams. A movable crossbeam 13 is slidably mounted on the support column 15 between the two crossbeams to achieve balanced force and smooth movement. The liquid-filling cylinders 14 are mounted downwards on the upper crossbeam 11, and the piston rod of the liquid-filling cylinder 14 is rigidly fixed to the movable crossbeam 13.

[0031] In this embodiment, when a single hydraulic circuit is used to simultaneously drive the pistons of six equal-diameter cylinders to move upward, the movable crossbeam 13 forces the six cylinders to move upward synchronously, ensuring consistent oil flow and pressure, and achieving the requirement of consistent constant-volume oil supply for each equal-diameter filling cylinder 14.

[0032] Specifically, the six equal-diameter filling cylinders 14 use 120mm diameter pistons with a two-chamber area ratio of 2. Taking the φ850mm diameter six-sided top press as an example, if the required filling oil volume per cylinder is 3.5L, then the stroke of a single filling cylinder 14 is 310mm, which can achieve a filling compression stroke of 6.17mm. Since the two-chamber area ratio is 2, if the filling pressure of the hinge beam cylinder 2 is 6MPa, then the pressure supplied by the pump set is 12MPa.

[0033] This embodiment eliminates the need for a drive cylinder, simplifying the structure and reducing costs.

[0034] like Figure 4 As shown, based on the above-mentioned filling synchronizer, this invention also proposes a hydraulic control system for a six-sided top press, including a low-pressure control section, a high-pressure control section, and a pump group section. The low-pressure control section includes six ultra-high-pressure hydraulic control check valves 3 and a first two-position four-way directional valve 41. The ultra-high-pressure hydraulic control check valves 3 serve as the boundary and isolation between the low-pressure and high-pressure sections. The low-pressure ends of the six ultra-high-pressure hydraulic control check valves 3 are respectively connected in series with the first two-position four-way directional valve 41 and a throttle valve 5. The T port of the first two-position four-way directional valve 41 is connected to the return oil system pipeline. The six throttle valves 5 are connected in parallel and then connected to the A port of the first three-position four-way directional valve 41. The P port of the first three-position four-way directional valve 41 is connected to the pump group system pressure. Hydraulic control check valves 6 are then connected in series below the throttle valves 5. The upper end of the hydraulic control check valves 6 is connected to the filling synchronizer through a three-way bypass. The filling synchronizer is connected to the second three-position four-way directional valve 72. The P port of the second and third position four-way directional valve 72 is connected to the pump group system pressure, and the T port is connected to the oil tank circuit.

[0035] During the filling process of the filling synchronizer, the electromagnet at the right end of the second and third position four-way reversing valve 72 is energized, and the hydraulic oil drives the front chambers of the six equal-diameter filling cylinders 14 to push the pistons upward. Under the forced synchronization action of the movable crossbeam 13, the rear chambers of the six equal-diameter filling cylinders 14 supply oil in equal amounts to the six hinge beam cylinders 2, realizing constant volume filling.

[0036] The return stroke control of the filling synchronizer energizes the right electromagnet of the first three-position four-way directional valve 71 and the left electromagnet of the second three-position four-way directional valve 72, causing the pistons of the six filling cylinders 14 of equal diameter to return, while the oil in the front chamber returns to the oil tank through port A to port T of the second three-position four-way directional valve 72.

[0037] In this embodiment, a hydraulically controlled check valve 6 can also be connected in series between the first and second position four-way directional valve and the throttle valve (e.g., Figure 7 (The connection method in the middle) connects the filling synchronizer between the first and second position four-way reversing valve 41 and the hydraulic control check valve 6 through a three-way connection.

[0038] The liquid-filling synchronizer in this embodiment has a simple structure and is the simplest implementation method of this invention.

[0039] Example 2:

[0040] like Figure 5-6 As shown, unlike the above embodiments, the liquid filling synchronizer in this embodiment includes a drive cylinder 16 and six liquid filling cylinders 14. The drive cylinder 16 includes a cylinder body 160, a front cylinder cover 161, and a drive piston 162. The front cylinder cover 161 is installed at the opening above the cylinder body 160, and the drive piston 162 is movably disposed inside the cylinder body 160. The liquid filling cylinders 14 are installed on the front cylinder cover 161, and the piston rod of the liquid filling cylinder 14 extends into the cylinder body 160 and is fixedly connected to the drive piston 162. Inlet and outlet connectors 10 are provided in the upper chambers of the six liquid filling cylinders 14 and the lower chamber of the drive cylinder 16.

[0041] In practical implementation, taking a φ850mm diameter six-sided top press as an example, six φ100mm, 400mm stroke, and 16MPa working pressure cylinders are selected as six equal-diameter cylinders, along with one φ600mm, 400mm stroke, and 6MPa working pressure cylinder. The piston area of ​​the large-diameter cylinder is 28.26dm. 2 The piston area of ​​a single equal-diameter hydraulic cylinder is 0.785 dm², and the total piston area of ​​six equal-diameter hydraulic cylinders is 4.71 dm². 2 The pressure ratio of the large-diameter hydraulic cylinder to the six equal-diameter hydraulic cylinders is 6:1, which can also be called a hydraulic synchronizing device with a pressure ratio. When the stroke of the large-diameter hydraulic cylinder is 400mm, the stroke of the six equal-diameter hydraulic cylinders is also 400mm, and the hydraulic oil supply to the corresponding hinge beam cylinder 2 is 3.14L. The piston area of ​​the φ850 cylinder diameter six-sided top press is 56.7dm. 2 The maximum displacement of the liquid filling is 5.54 mm, which can meet the compression displacement requirements of the liquid filling on the composite block.

[0042] In addition, a displacement sensor 17 is installed on the front cylinder head 161, which can detect the displacement of the filling cylinder 14 and provide a stroke for the filling cylinder 14 or prevent overtravel.

[0043] The filling synchronizer of this structure requires non-standard manufacturing of six equal-diameter cylinders and one large-diameter cylinder, resulting in higher costs. However, it has a larger pressure ratio. For filling pressures below 10MPa, the working pressure of the large-diameter cylinder is too low. But by utilizing the larger pressure ratio, the working pressure can be increased, raising the filling pressure to 30-40MPa. This is a better implementation method, as the pressure range for pressing solid blocks is being adjusted.

[0044] Accordingly, based on the filling synchronizer of this embodiment, a hydraulic control system for a six-sided top press is also proposed. This system differs from the hydraulic control system in Embodiment 1 above in that: the hydraulic control check valve 6 is located between the first two-position four-way directional valve 41 and the throttle valve 5; the rear chamber of the filling cylinder 14 is connected to the corresponding first two-position four-way directional valve 41 and the hydraulic control check valve 6 via a three-way valve; the inner chamber of the cylinder body 160 of the drive cylinder 16 is connected to the A port of the second three-position four-way directional valve 72; the P port of the second three-position four-way directional valve 72 is connected to the pump system pressure; and the T port is connected to the oil tank circuit. The specific structure is as follows: Figure 7 As shown.

[0045] In the filling process using the filling synchronizer provided in this embodiment, the electromagnet at the right end of the second three-position four-way reversing valve 72 is energized, and the hydraulic oil pushes the piston of the drive cylinder 16 upward, while simultaneously pushing the pistons of the six filling cylinders 14 of equal diameter, supplying an equal amount of oil to the six hinge beam cylinders 2, thereby achieving constant volume filling.

[0046] The return stroke control of the filling synchronizer energizes the right electromagnet of the first three-position four-way directional valve 71 and the left electromagnet of the second three-position four-way directional valve 72, causing the pistons of the six equal-diameter filling cylinders 14 to return, and simultaneously causing the piston of the drive cylinder 16 to return downward. The hydraulic oil returns to the oil tank through port A to port T of the second three-position four-way solenoid directional valve.

[0047] This liquid filling synchronizer has a pressure ratio of 6:1. When filling with liquid at a pressure below 10MPa, the pressure of the drive cylinder 16 is too low. However, if a liquid filling pressure of 30-40MPa is used, the pressure range for pressing solid blocks can be directly reached during the adjustment and operation of the six-sided top, which is also a good application method.

[0048] The hydraulic control system using this filling synchronizer has extremely small oil output error in the six filling cylinders 14. If the filling error of the six cylinders is required to be within ±0.050mm at the end of filling, then the constant volume oil supply error of the six cylinders of the synchronizer is within ±28.35mL. The filling synchronizer can fully achieve such oil supply accuracy.

[0049] In this embodiment, a hydraulically controlled check valve 6 can also be connected in series below the throttle valve 5 (such as...). Figure 6 (The connection method in the middle), and the filling synchronizer is connected between the throttle valve 5 and the hydraulic control check valve 6 through a three-way valve.

[0050] Example 3:

[0051] like Figure 8-9 As shown, compared with Embodiment 1, this embodiment differs in that: a drive cylinder 16 is also installed on the lower crossbeam 12, and the piston rod of the drive cylinder 16 is fixed upward to the movable crossbeam 13. The rear chambers of the six filling cylinders 14 have their own oil outlet and oil inlet connectors 10, and the front and rear chambers of the drive cylinder 16 have oil inlet and outlet connectors 10 respectively.

[0052] When the drive cylinder 16 moves upward, the hydraulic pressure pushes the pistons of the six filled cylinders 14 upward through the movable crossbeam 13, causing the six filled cylinders 14 to output hydraulic oil of equal capacity, thus forcing the six cylinders of equal diameter to move up and down synchronously. When the movable crossbeam 13 moves upward, the six filled cylinders 14 supply oil to the six hinge beam cylinders 2 in a constant-volume manner, achieving synchronous filling of the hinge beam cylinders 2. Generally, the hydraulic pressure of the drive cylinder 16 is below 12 MPa.

[0053] In practical implementation, taking a φ850mm diameter six-sided top press as an example, six φ100mm, 400mm stroke, and 16MPa working pressure hydraulic cylinders are selected as six filling cylinders 14, and one φ250mm, 400mm stroke, and 16MPa working pressure drive cylinder 16 is selected; the piston area of ​​a single filling cylinder 14 is 0.785dm. 2 The total area of ​​the 6 hydraulic cylinders and 14 pistons is 4.71 dm². 2 The piston area of ​​the drive cylinder 16 is 4.90 dm. 2 The piston area is slightly larger than that of the equal-diameter filling cylinder 14. When the stroke of the driving cylinder 16 is 400mm, the stroke of the six filling cylinders 14 is also 400mm, resulting in a filling oil supply of 3.14L to the corresponding hinge beam cylinder 2. The piston area of ​​the φ850 cylinder diameter six-sided top press is 56.7dm. 2 The maximum displacement during filling is 5.54 mm. If the driving hydraulic pressure of the driving cylinder 16 is 10 MPa, the thrust generated is 49000 kg, so that each filling cylinder 14 receives 8117 kg of thrust and the resulting hydraulic pressure is 10.34 MPa, which can meet the filling pressure and compression displacement requirements of the synthetic block.

[0054] In addition, in this embodiment, a displacement sensor is provided between the movable crossbeam 13 and the upper crossbeam 11 or the lower crossbeam 12, which can detect the displacement of the filling cylinder 14 and provide a displacement signal for the electronic control.

[0055] like Figure 10 As shown, the hydraulic control system using the filling synchronizer in this embodiment differs from the previous embodiment in that: the low-pressure end of each ultra-high pressure hydraulic control check valve 63 is connected in series with a hydraulic control check valve 6 and then connected to port A of the corresponding first two-position four-way directional valve 41. The hydraulic control check valve 6 blocks the downward passage of hydraulic oil when the filling synchronizer is filling and supplying oil. The P port of the first two-position four-way directional valve 41 is connected in series with a throttle valve 5 and then converges and is connected to port A of the first three-position four-way directional valve 71.

[0056] The rear chamber of the filling cylinder 14 is connected in series with the first check valve 91 and then via a three-way valve between the corresponding hydraulic control check valve 6 and the ultra-high pressure hydraulic control check valve 3. When controlling the forward and backward movement of the hinge beam cylinder 2, the first check valve 91 can block the filling synchronizer circuit. The rear chamber of the drive cylinder 16 is connected to port A of the second three-position four-way directional valve 72. Port B of the second three-position four-way directional valve 72 is connected to the front chamber of the drive cylinder 16. Port P is connected to the pump system pressure, and port T is connected to the oil tank circuit.

[0057] The rear chamber of the filling cylinder 14 is also equipped with a second check valve 93 that connects to the oil tank, and the front chamber of the filling cylinder 14 is equipped with a passage that connects to the oil tank. When the filling cylinder 14 of the filling synchronizer discharges oil, the second check valve 93 is closed. When the drive cylinder 16 returns, it pulls the filling cylinder 14 back, and the filling cylinder 14 descends and draws oil from the oil tank through the second check valve 93 to fill the rear chamber of the filling cylinder 14. The pipeline connecting the front chamber (rod chamber) to the oil tank draws hydraulic oil into the front chamber when the cylinder moves upward and discharges hydraulic oil when the cylinder returns.

[0058] A two-position two-way directional valve 92 is also connected in parallel to the second one-way valve 93. During the filling stage, the valve controls the oil discharge of the six given hinge beam cylinders 2 by controlling their on / off state. This can control the displacement and compression stroke of any hinge beam cylinder 2, or the synchronous pressure equalization at both ends of the high-assembly-height composite block at the beginning of filling.

[0059] The hydraulic system of the six-sided top press of this invention has a filling synchronizer, which uses a constant-volume hydraulic oil supply to the six hinge beam cylinders. It is not affected by the different damping of the hydraulic cylinders, the different piston positions, the length and number of bends of the hydraulic pipeline from the hydraulic station to the hinge beam cylinders, or the viscosity changes caused by oil temperature. It achieves precise control of the starting synchronization of the filling step and the filling displacement during the filling process, so that the six-sided top press has excellent synchronization and eliminates many accidents or factors caused by poor synchronization.

[0060] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A hydraulic control system for a six-sided top press, comprising a low-pressure control section, a high-pressure control section, and a pump unit section. The low-pressure control section includes six ultra-high-pressure hydraulic control check valves, a first and second-position four-way directional valve, and a throttle valve. The ultra-high-pressure hydraulic control check valves serve as the boundary and isolation between the low-pressure and high-pressure sections. The low-pressure ends of the six ultra-high-pressure hydraulic control check valves are respectively connected in series with the first and second-position four-way directional valve and the throttle valve. The T port of the first and second-position four-way directional valve is connected to the return oil system pipeline. The six throttle valves are connected in parallel and then connected to the A port of the first three-position four-way directional valve. The P port of the first three-position four-way directional valve is connected to the pump unit system pressure. The system is characterized in that: A hydraulic control check valve is connected in series between the low-pressure end of the six ultra-high pressure hydraulic control check valves and the A port of the first and second position four-way directional valve, or between the P port of the first and second position four-way directional valve and the throttle valve, or below the throttle valve. A liquid filling synchronizer is connected to the upper end of the hydraulic control check valve through a three-way bypass, and the liquid filling synchronizer is connected to the second and third position four-way directional valve. The liquid filling synchronizer includes a beam and six liquid filling cylinders. The beam includes an upper crossbeam, a support column, and a lower crossbeam. The support column is vertically fixed between the two crossbeams. The movable crossbeam is slidably mounted on the support column. The liquid filling cylinders are mounted downwards on the upper crossbeam. The piston rod of the liquid filling cylinder is fixedly connected to the movable crossbeam. A drive cylinder is installed on the lower crossbeam, and the piston rod of the drive cylinder is fixed upward to the movable crossbeam. The hydraulic control check valve is connected between the low-pressure end of the six ultra-high pressure hydraulic control check valves and the A port of the first two-position four-way directional valve; the rear chamber of the filling cylinder is connected in series with the first check valve and then connected between the corresponding ultra-high pressure hydraulic control check valve and the hydraulic control check valve; the rear chamber of the driving cylinder is connected to the A port of the second three-position four-way directional valve, the B port of the second three-position four-way directional valve is connected to the front chamber of the driving cylinder, the P port is connected to the pump group system pressure, and the T port is connected to the oil tank circuit; The rear chamber of the filling cylinder is also provided with a second one-way valve that connects to the oil tank, and the front chamber of the filling cylinder is provided with a passage that connects to the oil tank. A two-position two-way directional valve is also connected in parallel to the second check valve.

2. The hydraulic control system for the six-sided top press according to claim 1, characterized in that: The filling synchronizer is also equipped with a displacement sensor for detecting the displacement of the filling cylinder.

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