A hydraulic system for the movement of the ram of a large-tonnage superplastic forming equipment

Abstract

The present invention provides a hydraulic system for the movement of a pressure head of a large-tonnage superplastic forming device, comprising an oil tank, a pump drive component, a filling valve, an oil cylinder, a servo flow valve group and an electronic control component, wherein the pump drive component and the servo flow valve group are both electrically connected to the electronic control component; a filling valve is installed on the first pipeline between the upper chamber of the oil cylinder and the oil tank; the outlet of the pump drive component is connected to the upper chamber of the oil cylinder, and the inlet of the pump drive component is connected to the oil tank; the servo flow valve group comprises a two-position two-way servo flow valve and a first three-position four-way solenoid valve, the A port of the two-position two-way servo flow valve is connected to the lower chamber of the oil cylinder, and the B port of the two-position two-way servo flow valve is connected to the oil tank; the A port of the first three-position four-way solenoid valve is connected to the first pilot control oil port P1 of the two-position two-way servo flow valve, the B port of the first three-position four-way solenoid valve is connected to the second pilot control oil port P2 of the two-position two-way servo flow valve, the T port of the first three-position four-way solenoid valve is connected to the oil tank, and the P port is connected to external control oil.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic control of superplastic forming equipment, and in particular relates to a hydraulic system for the movement of a pressure head of a large-tonnage superplastic forming equipment. Background Art

[0002] At present, large-tonnage superplastic forming equipment is a typical high-end forming equipment, which is mainly used in the aerospace field to meet the requirements of lightweight and forming quality of titanium alloy, aluminum alloy and other parts in this field. Large-tonnage superplastic forming equipment refers to superplastic forming equipment with a nominal force of not less than 500t. Generally, the working speed range of the pressure head of large-tonnage superplastic forming equipment is required to be 0.5-2mm / s, and the pressure head stroke is not less than 1000mm. The main parameters that can be achieved by the pressure head of large-tonnage superplastic forming equipment are that the slow speed range of the pressure head is 0.5-2mm / s, the fast speed range of the pressure head is 10-100mm / s, and the fast speed is adjustable, and the return speed range of the pressure head is 10-100mm / s, and the return speed is adjustable. The control range of the pressure head tonnage is 5%-100% of the rated tonnage, the position control accuracy of the pressure head is ±0.1mm, and the pressure control accuracy of the pressure head is ±1% of the rated pressure. The speed of the pressure head going down and back up is required to be as fast as possible, which can improve work efficiency and reduce energy loss.

[0003] The movement of the pressure head of the current large-tonnage superplastic forming equipment mainly has the following problems:

[0004] First, the pressure head is driven by pump flow quickly, which requires a large pump displacement. Due to the limitation of the pump displacement, the pressure head's rapid descent speed is low, affecting the equipment's manufacturing efficiency.

[0005] Under the existing circumstances, the upper chamber of the oil cylinder is connected to the filling oil tank through the filling valve. The outlet of the lower chamber of the oil cylinder is provided with two parallel pipelines, on which a directional cartridge valve and a directional cartridge valve with a stroke limiting mechanism are respectively installed, and the outlets of the directional cartridge valve and the directional cartridge valve with a stroke limiting mechanism are both connected to the oil tank.

[0006] When the pressure head is going down quickly, it is going down quickly by its own weight, and the no-load down speed is fast. The directional cartridge valve with stroke limiting mechanism mentioned above works, and the hydraulic oil in the lower chamber flows back to the oil tank through the directional cartridge valve with stroke limiting mechanism and the pipeline where it is located. The opening of the directional cartridge valve with stroke limiting mechanism is manually adjusted to adjust the speed of the pressure head going down quickly.

[0007] When the pressure head moves down slowly, the directional cartridge valve works, and the hydraulic oil in the lower chamber flows back to the oil tank through the directional cartridge valve and the pipeline where it is located. When the pressure head changes from fast down action to slow down action, the pressure head will produce a large impact, and the pressure head will work unsteadily. When the pressure head changes from fast down action to slow down action, the working conversion stroke of the pressure head is long, and the position control is inaccurate.

[0008] In addition, since the rapid descent speed of the pressure head needs to be manually adjusted by adjusting the opening of the directional cartridge valve with a stroke limiting mechanism, the rapid descent speed of the pressure head is controlled by controlling the oil return speed, which makes the operation inconvenient.

[0009] Second, the power source uses a three-phase asynchronous motor to drive a variable pump or a proportional pump, and the movement speed of the pressure head is controlled by controlling the opening of the proportional valve or the pumping speed of the proportional pump. The above-mentioned three-phase asynchronous motor is a conventional motor and cannot be implemented to adapt to the working conditions of the pump, resulting in a large loss of power energy. Summary of the invention

[0010] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a hydraulic system for the movement of the ram of large-tonnage superplastic forming equipment. The lower chamber of the ram main cylinder is controlled by a servo flow valve. The ram's fast lowering speed can be automatically and steplessly adjusted when the ram is lowered quickly, and there is no impact in the process of switching from fast lowering to slow lowering.

[0011] To achieve this object, the present invention adopts the following technical solutions:

[0012] A hydraulic system for the movement of a ram of a large-tonnage superplastic forming device comprises an oil tank, a pump drive assembly, a liquid filling valve, an oil cylinder, a servo flow valve group and an electric control assembly, wherein the pump drive assembly and the servo flow valve group are both electrically connected to the electric control assembly;

[0013] The filling valve is installed on the first pipeline between the upper chamber of the oil cylinder and the oil tank;

[0014] The outlet of the pump drive assembly is connected to the upper chamber of the oil cylinder via a second pipeline, and the inlet of the pump drive assembly is connected to the oil tank;

[0015] The servo flow valve group includes a two-position two-way servo flow valve and a first three-position four-way solenoid valve, the A port of the two-position two-way servo flow valve is connected to the lower chamber of the oil cylinder via a third pipeline, and the B port of the two-position two-way servo flow valve is connected to the oil tank;

[0016] The A port of the first three-position four-way solenoid valve is connected to the first pilot control oil port P1 of the two-position two-way servo flow valve, the B port of the first three-position four-way solenoid valve is connected to the second pilot control oil port P2 of the two-position two-way servo flow valve, the T port of the first three-position four-way solenoid valve is connected to the oil tank, and the P port of the first three-position four-way solenoid valve is connected to the external control oil;

[0017] Either the A port or the B port of the first three-position four-way solenoid valve is selectively connected to the P port to control the opening of the two-position two-way servo flow valve.

[0018] Preferably, a first electromagnetic ball valve cartridge valve group is provided on the third pipeline;

[0019] The first electromagnetic ball valve cartridge valve group includes a first two-position three-way electromagnetic valve and a first directional cartridge valve, and the B port of the first two-position three-way electromagnetic valve and the B port of the first directional cartridge valve are both connected to the lower chamber of the oil cylinder;

[0020] Port A of the first two-position three-way solenoid valve is connected to port C of the first directional cartridge valve;

[0021] The T port of the first two-position three-way solenoid valve is connected to the oil tank;

[0022] The port A of the first directional cartridge valve is connected to the port A of the two-position two-way servo flow valve and the outlet of the pump drive assembly at the same time.

[0023] Preferably, the pump driving assembly comprises an oil pump assembly and a flow dividing assembly arranged on the second pipeline;

[0024] The flow diversion assembly includes a second directional cartridge valve, a third directional cartridge valve and a second three-position four-way solenoid valve;

[0025] The outlet of the oil pump assembly is simultaneously connected to the P port of the second three-position four-way solenoid valve, the B port of the second directional cartridge valve, and the B port of the third directional cartridge valve;

[0026] The T port of the second three-position four-way solenoid valve is connected to the oil tank, the C port and the A port of the second directional cartridge valve are simultaneously connected to the A port of the second three-position four-way solenoid valve, and the A port of the second directional cartridge valve is connected to the upper chamber of the oil cylinder;

[0027] Port A and port C of the third directional cartridge valve are simultaneously connected to port B of the second three-position four-way solenoid valve;

[0028] The A port of the third directional cartridge valve is also connected to the A port of the two-position two-way servo flow valve.

[0029] Preferably, a second electromagnetic ball valve cartridge valve group is also provided on the second pipeline;

[0030] The second electromagnetic ball valve cartridge valve group includes a second two-position three-way electromagnetic valve and a fourth cartridge valve, and the port A of the second directional cartridge valve is connected to the port A of the fourth cartridge valve;

[0031] Port B of the fourth cartridge valve is connected to the upper chamber of the oil cylinder;

[0032] The C port of the fourth cartridge valve is connected to the A port of the second two-position three-way solenoid valve;

[0033] The T port of the second two-position three-way solenoid valve is connected to the oil tank.

[0034] Preferably, a second proportional relief valve is further provided between the fourth cartridge valve and the second directional cartridge valve, and the second proportional relief valve is used to control the pressure of the hydraulic oil in the pipeline.

[0035] Preferably, the oil pump assembly comprises a servo motor, a double metering pump, a fourth direction cartridge valve and a fifth direction cartridge valve, and the servo motor is connected to the double metering pump;

[0036] The double quantitative pump comprises a high-pressure pump and a low-pressure pump, and the outlet of the high-pressure pump is connected to the A port of the fourth directional cartridge valve;

[0037] The B port and the C port of the fourth directional cartridge valve are connected to the P port of the second three-position four-way solenoid valve, the B port of the second directional cartridge valve and the B port of the third directional cartridge valve;

[0038] The outlet of the low-pressure pump is connected to the A port of the fifth directional cartridge valve; the B port and the C port of the fifth directional cartridge valve are both connected to the P port of the second three-position four-way solenoid valve, the B port of the second directional cartridge valve and the B port of the third directional cartridge valve.

[0039] Preferably, the oil pump assembly further comprises a pressure relief assembly, the high-pressure pump is connected to the pressure relief assembly, and / or the low-pressure pump is connected to the pressure relief assembly;

[0040] The pressure relief assembly includes a pressure cartridge valve, a relief valve and a two-position four-way solenoid valve;

[0041] The A port and the T port of the pressure cartridge valve are connected to the outlet of the high-pressure pump, and / or the A port and the T port of the pressure cartridge valve are connected to the outlet of the low-pressure pump;

[0042] Port B of the pressure cartridge valve is connected to the oil tank;

[0043] The port A of the relief valve is connected to the outlet of the high-pressure pump, and / or the port A of the relief valve is connected to the outlet of the low-pressure pump;

[0044] The T port of the overflow valve is connected to the oil tank;

[0045] The P port of the two-position four-way solenoid valve is connected to the outlet of the high-pressure pump, and / or the P port of the two-position four-way solenoid valve is connected to the outlet of the low-pressure pump;

[0046] The A port and the T port of the two-position four-way solenoid valve are both connected to the oil tank, and the B port of the two-position four-way solenoid valve is a normally closed port.

[0047] Preferably, the hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment further comprises a third two-position four-way solenoid valve, the P port of the third two-position four-way solenoid valve is connected to the B port and the C port of the fourth directional cartridge valve, and the A port of the third two-position four-way solenoid valve is in a normally closed state;

[0048] The B port of the third two-position four-way solenoid valve is connected to the pilot control oil port of the filling valve, and the T port of the third two-position four-way solenoid valve is connected to the oil tank.

[0049] Preferably, the hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment further comprises an accumulator assembly, and the accumulator assembly comprises an auxiliary pump oil assembly, an accumulator and an accumulator control assembly;

[0050] The outlet of the auxiliary oil pump assembly is connected to the accumulator control assembly, the accumulator control assembly is connected to the accumulator, and the auxiliary oil pump assembly can supply oil to the accumulator through the accumulator control assembly;

[0051] The accumulator control assembly is connected to the P port of the first three-position four-way solenoid valve, and the accumulator can supply oil to the P port of the first three-position four-way solenoid valve through the accumulator control assembly.

[0052] Preferably, the auxiliary pump oil assembly comprises an auxiliary motor, an auxiliary pump and an electromagnetic unloading valve, the output shaft of the auxiliary motor is connected to the auxiliary pump, and the outlet of the auxiliary pump is connected to the connection port of the energy accumulator control assembly;

[0053] The electromagnetic unloading valve is arranged on the fourth pipeline between the energy accumulator control assembly and the auxiliary pump;

[0054] The electromagnetic unloading valve restricts the hydraulic oil from flowing from the auxiliary pump to the accumulator control assembly in one direction;

[0055] And the electromagnetic unloading valve is used to control the oil pressure of the hydraulic oil in the fourth pipeline.

[0056] Compared with the prior art, the present invention has the following beneficial effects: the upper chamber of the oil cylinder is connected to the oil tank through the filling valve. When the pressure head drops, in the initial stage, the upper chamber of the oil cylinder forms a negative pressure due to the drop of the pressure head for a short time. The filling valve is opened, and oil is directly supplied to the upper chamber of the oil cylinder through the oil tank, ensuring that the upper chamber quickly enters the oil when the pressure head drops quickly. The hydraulic oil in the lower chamber flows back to the oil tank through the A port and the B port of the two-position two-way servo flow valve.

[0057] The lower chamber is connected to the A port of the two-position two-way servo flow valve, and is connected to the P port through the A port or the B port of the first three-position four-way solenoid valve, and provides pilot control oil to the first pilot control oil port P1 or the second pilot control oil port P2, thereby controlling the opening of the two-position two-way servo flow valve, so that the opening of the two-position two-way servo flow valve is adapted to the descending speed of the pressure head.

[0058] When the pressure head is about to drop, the electronic control component controls the coordinated operation of the first three-position four-way solenoid valve and the two-position two-way servo flow valve. The first three-position four-way solenoid valve adaptively adjusts the opening of the two-position two-way servo flow valve through the electronic control component, which can realize stepless automatic adjustment of the pressure head speed. The rapid drop speed of the pressure head is controlled by the electronic control component to adaptively work the servo flow valve group, thereby realizing automatic control of the rapid drop of the pressure head, accurate control without manual operation, and improving the degree of work automation.

[0059] In addition, when the pressure head moves down slowly, the pump drive assembly supplies oil to the upper chamber of the oil cylinder through the second pipeline. At this time, the filling valve is closed. When the pressure head changes from a fast down action to a slow down action, the opening of the two-position two-way servo flow valve can be adaptively adjusted through the electronic control assembly to control the movement speed of the pressure head. Therefore, when the pressure head changes from a fast down action to a slow down action, the pressure head will not produce a large impact and the pressure head works smoothly.

[0060] In addition, because the electronic control component can control the coordinated work of the first three-position four-way solenoid valve and the second two-position two-way servo flow valve in real time, the feedback speed is fast, and the conversion stroke is short when the pressure head changes from a fast downward action to a slow downward action, and the position control is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 This is a control schematic diagram of the hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment in the present invention.

[0062] Among them, 100, pump drive assembly; 1001, pressure relief assembly; 1002, diverter assembly; 1003, pump oil assembly; 200, accumulator assembly; 1, oil cylinder; 2, filling valve; 3, position sensor; 4, oil tank; 5, auxiliary motor; 6, auxiliary pump; 7, servo motor; 8, double quantitative pump; 10, first pressure cartridge valve; 11, fourth direction cartridge valve; 13, second pressure cartridge valve; 14, fifth direction cartridge valve; 16, second direction cartridge valve; 17, third direction cartridge valve; 18, second three-position four-way solenoid valve; 20, second solenoid ball valve cartridge valve group; 201, fourth cartridge valve; 21, second pressure sensor; 23, servo flow valve group; 23 1. First three-position four-way solenoid valve; 24. First solenoid ball valve cartridge valve group; 241. First directional cartridge valve; 25. First relief valve; 26. Superimposed one-way throttle valve; 28. Solenoid unloading valve; 30. Accumulator; 31. Accumulator control assembly; 311. Fifth relief valve; 312. Normally closed switch; 313. Normally open switch; 32. Auxiliary pump oil assembly; 36. Third relief valve; 37. Fourth relief valve; 38. Third pressure sensor; 40. Fourth pressure sensor; 41. Filter assembly; 45. First pressure sensor; 46. First shuttle valve; 47. Second shuttle valve; 50. First pipeline; 51. Second pipeline; 53. Third pipeline; 54. Fourth pipeline;

[0063] YA1, first two-position four-way solenoid valve; YA2, second two-position four-way solenoid valve; YA6, third two-position four-way solenoid valve; YAB, two-position two-way servo flow valve; YA4, first two-position three-way solenoid valve; YA5, second two-position three-way solenoid valve; YAA, second proportional relief valve. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0065] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0067] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing 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, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0068] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0070] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0071] like Figure 1As shown, in this embodiment, the main parameters that can be achieved by the ram of the large-tonnage superplastic forming equipment are that the working speed range of the ram is required to be 0.5-2mm / s, and the ram stroke is not less than 1000mm. The slow descent speed range of the ram is 0.5-2mm / s, the fast descent speed range of the ram is 10-100mm / s, and the fast descent speed of the ram is adjustable. The return speed range of the ram is 10-100mm / s, and the return speed is adjustable. The tonnage control range of the ram is 5%-100% of the rated tonnage, the position control accuracy of the ram is ±0.1mm, and the pressure control accuracy of the ram is ±1% of the rated pressure.

[0072] In this embodiment, a hydraulic system for the movement of the ram of a large-tonnage superplastic forming equipment is provided, and the hydraulic system includes an oil tank 4, a pump drive assembly 100, a filling valve 2, an oil cylinder 1, a servo flow valve group 23 and an electronic control assembly, and the pump drive assembly 100 and the servo flow valve group 23 are both electrically connected to the electronic control assembly.

[0073] A filling valve 2 is installed on the first pipeline 50 between the upper chamber of the oil cylinder 1 and the oil tank 4. In this embodiment, the filling valve 2 has a pre-discharge function, requiring the oil flow rate to be no more than 2.5m / s, the forward opening pressure to be no more than 0.5bar, and the reverse opening can be controlled by external control oil.

[0074] The outlet of the pump drive assembly 100 is connected to the upper chamber of the oil cylinder 1 through the second pipeline 51, and the inlet of the pump drive assembly 100 is connected to the oil tank 4. The flow in the first pipeline 50 is greater than the flow in the second pipeline 51, which can achieve the control pressure head to drop quickly.

[0075] The servo flow valve group 23 includes a two-position two-way servo flow valve YAB and a first three-position four-way solenoid valve 231. The A port of the two-position two-way servo flow valve YAB is connected to the lower chamber of the cylinder 1 via the third pipeline 3, and the B port of the two-position two-way servo flow valve YAB is connected to the oil tank 4.

[0076] The A port of the first three-position four-way solenoid valve 231 is connected to the first pilot control oil port P1 of the two-position two-way servo flow valve YAB, the B port of the first three-position four-way solenoid valve 231 is connected to the second pilot control oil port P2 of the two-position two-way servo flow valve YAB, the T port of the first three-position four-way solenoid valve 231 is connected to the oil tank 4, and the P port of the first three-position four-way solenoid valve 231 is connected to the external control oil. Either the A port or the B port of the first three-position four-way solenoid valve 231 is connected to the P port to control the opening of the two-position two-way servo flow valve YAB.

[0077] In this embodiment, the electromagnetic interface of the two-position two-way servo flow valve YAB and the electromagnetic interface of the first three-position four-way solenoid valve 231 are both electrically connected to the electronic control component to ensure that the two-position two-way servo flow valve YAB and the first three-position four-way solenoid valve 231 work in coordination with each other.

[0078] In this embodiment, the upper chamber of the oil cylinder 1 is connected to the oil tank 4 through the filling valve 2. When the pressure head drops, in the initial stage, the upper chamber of the oil cylinder forms a negative pressure due to the drop in the pressure head for a short time. The filling valve 2 opens and directly supplies oil to the upper chamber of the oil cylinder through the oil tank 4 to ensure that the upper chamber quickly enters the oil during the rapid drop of the pressure head. The hydraulic oil in the lower chamber flows back to the oil tank 4 through the A port and the B port of the two-position two-way servo flow valve YAB. The lower chamber is connected to the A port of the two-position two-way servo flow valve YAB, and is connected to the P port through the A port or the B port of the first three-position four-way solenoid valve 231, providing pilot control oil for the first pilot control oil port P1 or the second pilot control oil port P2, thereby controlling the opening of the two-position two-way servo flow valve YAB, so that the opening of the two-position two-way servo flow valve YAB can adapt to the falling speed of the pressure head.

[0079] When the pressure head is about to go down, the electric control component controls the first three-position four-way solenoid valve 231 and the two-position two-way servo flow valve YAB to work in coordination, and the first three-position four-way solenoid valve 231 adaptively adjusts the opening of the two-position two-way servo flow valve YAB through the electric control component, so as to realize stepless automatic adjustment of the speed of the pressure head. In this embodiment, the rapid down speed of the pressure head is controlled by the electric control component to adaptively work the servo flow valve group 23, thereby realizing automatic control of the rapid down speed of the pressure head, accurate control without manual operation, and improving the degree of work automation.

[0080] In addition, when the pressure head moves down slowly, the pump drive assembly 100 supplies oil to the upper chamber of the oil cylinder 1 through the second pipeline 51. At this time, the filling valve 2 is closed. When the pressure head changes from a fast down action to a slow down action, the opening of the two-position two-way servo flow valve YAB can be adaptively adjusted through the electronic control assembly to control the movement speed of the pressure head. Therefore, when the pressure head changes from a fast down action to a slow down action, the pressure head will not produce a large impact, and the pressure head works smoothly.

[0081] In addition, because the electronic control component can control the coordinated work of the first three-position four-way solenoid valve 231 and the two-position two-way servo flow valve YAB in real time, the feedback speed is fast, and the conversion stroke is short when the pressure head changes from a fast downward action to a slow downward action, and the position control is more accurate.

[0082] Specifically, the above-mentioned two-position two-way servo flow valve YAB is a servo flow valve with a control voltage range of 0-+10V, which can achieve the best dynamic performance of high-speed closed-loop control and precise flow control, thereby realizing the fast downward action of the pressure head, the conversion of fast downward to slow downward action, and slow downward action. The speed of the pressure head is adjustable, and when the pressure head is converted from fast downward action to slow downward action, the conversion is impact-free.

[0083] When the P port and A port of the first three-position four-way solenoid valve 231 are connected, and the B port and T port are connected, the hydraulic oil pumped by the pump drive assembly 100 is delivered to the first pilot control oil port P1 of the two-position two-way servo flow valve YAB through the P port and the A port, controlling the opening of the two-position two-way servo flow valve YAB, realizing precise flow control, and thus controlling the descending speed of the pressure head.

[0084] Preferably, the third pipeline 53 is also provided with a first electromagnetic ball valve cartridge valve group 24, which is arranged between the lower chamber of the oil cylinder 1 and the A port of the two-position two-way servo flow valve YAB. The first electromagnetic ball valve cartridge valve group 24 includes a first two-position three-way electromagnetic valve YA4 and a first directional cartridge valve 241. The B port of the first two-position three-way electromagnetic valve YA4 and the B port of the first directional cartridge valve 241 are both connected to the lower chamber of the oil cylinder 1. The A port of the first two-position three-way electromagnetic valve YA4 is connected to the C port of the first directional cartridge valve 241. The T port of the first two-position three-way electromagnetic valve YA4 is connected to the oil tank 4. The A port of the first directional cartridge valve 241 is simultaneously connected to the A port of the two-position two-way servo flow valve YAB and the outlet of the pump drive assembly 100.

[0085] A first electromagnetic ball valve cartridge valve group 24 is set between the lower chamber of the oil cylinder 1 and the two-position two-way servo flow valve YAB. The purpose of setting the first electromagnetic ball valve cartridge valve group 24 is to prevent the hydraulic oil in the lower chamber of the oil cylinder 1 from directly acting on the two-position two-way servo flow valve YAB for a long time when the two-position two-way servo flow valve YAB is in a closed state, thereby preventing the two-position two-way servo flow valve YAB from causing impact on the two-position two-way servo flow valve YAB and reducing the service life of the two-position two-way servo flow valve YAB.

[0086] The first two-position three-way solenoid valve YA4 controls the opening and closing of the first directional cartridge valve 241. When the first two-position three-way solenoid valve YA4 is in a power-off state, the B port and the A port of the first two-position three-way solenoid valve YA4 are connected. At this time, the A port of the first two-position three-way solenoid valve YA4 is connected to the C port of the first directional cartridge valve 241, and the B port of the first two-position three-way solenoid valve YA4 is connected to the B port of the first directional cartridge valve 241. At this time, the oil pressure of the hydraulic oil at the B port of the first directional cartridge valve 241 and the control oil at the C port are both high pressure. If the oil pressure of the hydraulic oil at the A port of the first directional cartridge valve 241 is low pressure, at this time, the first directional cartridge valve 241 is in a closed state, and the hydraulic oil in the lower chamber of the oil cylinder 1 will not flow back to the two-position two-way servo flow valve YAB through the first directional cartridge valve 241. If the pressure of the hydraulic oil at the A port of the first directional cartridge valve 241 is greater than the pressure of the B port and the C port, the A port and the B port are connected in one direction. The “high” and “low” of the oil pressures at the A port, the B port and the C port of the first directional cartridge valve 241 are described by the relative values ​​of the oil pressures at the above-mentioned oil ports, and the following statements are the same.

[0087] When the first two-position three-way solenoid valve YA4 is in the energized state, at this time, the A port and the T port of the first two-position three-way solenoid valve YA4 are connected, and the pressure of the pilot control oil at the C port of the first directional cartridge valve 241 is 0. If the oil pressure of the hydraulic oil at the A port is high pressure, the hydraulic oil of the first two-position three-way solenoid valve YA4 flows from the A port to the B port. If the oil pressure of the hydraulic oil at the B port is high pressure, the hydraulic oil of the first two-position three-way solenoid valve YA4 flows from the B port to the A port. At this time, the first two-position three-way solenoid valve YA4 realizes two-way circulation.

[0088] Preferably, a first relief valve 25 is provided between the lower chamber of the oil cylinder 1 and the first directional cartridge valve 241. The threshold of the first relief valve 25 is a first preset pressure value. When the pressure value of the hydraulic oil in the pipeline between the lower chamber of the oil cylinder 1 and the first directional cartridge valve 241 is greater than the first preset pressure value, the hydraulic oil flows back to the oil tank 4 through the first relief valve 25. In this embodiment, the threshold of the first relief valve 25 is 21 MPa.

[0089] Further preferably, a first pressure sensor 45 is also provided on the pipeline between the lower chamber of the oil cylinder 1 and the first directional cartridge valve 241 . The first pressure sensor 45 is used to detect the pressure in the pipeline in real time and transmit the pressure to the electronic control component, which transmits the signal to the first overflow valve 25 .

[0090] Preferably, the pump drive assembly 100 includes an oil pump assembly 1003 and a flow diverter assembly 1002 disposed on the second pipeline 51, wherein the flow diverter assembly 1002 includes a second directional cartridge valve 16, a third directional cartridge valve 17, and a second three-position four-way solenoid valve 18, wherein the outlet of the oil pump assembly 1003 is simultaneously connected to the P port of the second three-position four-way solenoid valve 18, the B port of the second directional cartridge valve 16, and the B port of the third directional cartridge valve 17. The T port of the second three-position four-way solenoid valve 18 is connected to the oil tank 4, the C port and the A port of the second directional cartridge valve 16 are simultaneously connected to the A port of the second three-position four-way solenoid valve 18, and the A port of the second directional cartridge valve 16 is connected to the upper chamber of the oil cylinder 1. The A port and the C port of the third directional cartridge valve 17 are simultaneously connected to the B port of the second three-position four-way solenoid valve 18. The A port of the third directional cartridge valve 17 is also connected to the A port of the two-position two-way servo flow valve YAB.

[0091] When the second three-position four-way solenoid valve 18 is in the de-energized state, the P port of the second three-position four-way solenoid valve 18 is connected to the A port, and the B port is connected to the T port. When the pump oil assembly 1003 flows from the P port of the second three-position four-way solenoid valve 18 to the A port, and provides pilot control oil to the second directional cartridge valve 16, at this time, the pressure of the pilot control oil at the A port and the C port of the second directional cartridge valve 16 is the same as the pressure of the hydraulic oil at the B port, and the second directional cartridge valve 16 remains in the closed state, and the hydraulic oil will not flow to the upper chamber of the oil cylinder 1 through the second directional cartridge valve 16. At this time, the pump oil assembly 1003 simultaneously supplies oil to the third directional cartridge valve 17, because the oil pressure of the pilot control oil at the B port of the third directional cartridge valve 17 is high pressure, and the C port and the A port are both connected to the oil tank 4, and the oil pressure of the pilot control oil at the A port and the C port is low pressure. The hydraulic oil flows from port B to port A, and then flows back to the oil tank 4 through port B and port T of the second three-position four-way solenoid valve 18. Therefore, the hydraulic oil will not flow to the two-position two-way servo flow valve YAB and the first electromagnetic ball valve cartridge valve group 24 through the third directional cartridge valve 17. That is, when the second three-position four-way solenoid valve 18 loses power, the second directional cartridge valve 16 and the third directional cartridge valve 17 both block the passage of the hydraulic oil.

[0092] Preferably, a first shuttle valve 46 is provided on the pipeline between the third directional cartridge valve 17 and the second three-position four-way solenoid valve 18, the B port of the second three-position four-way solenoid valve 18 is connected to the P1 port of the first shuttle valve 46, the P2 port of the first shuttle valve 46 is connected to the A port of the third directional cartridge valve 17, and the P3 port of the first shuttle valve 46 is connected to the C port of the third directional cartridge valve 17.

[0093] Preferably, a second shuttle valve 47 is arranged on the pipeline between the second directional cartridge valve 16 and the second three-position four-way solenoid valve 18, the A port of the second three-position four-way solenoid valve 18 is connected to the P1 port of the second shuttle valve 47, the A port of the second directional cartridge valve 16 is connected to the P2 port of the second shuttle valve 47, and the P3 port of the second shuttle valve 47 is connected to the C port of the second directional cartridge valve 16.

[0094] When the YA3a end of the second three-position four-way solenoid valve 18 is in the energized state, the P port and the B port of the second three-position four-way solenoid valve 18 are connected, and the A port and the T port are connected. The hydraulic oil pumped by the pump oil assembly 1003 flows from the P port of the second three-position four-way solenoid valve 18 to the B port, providing pilot control oil for the A port and the C port of the third directional cartridge valve 17. At this time, the pressures of the A port, the B port and the C port of the third directional cartridge valve 17 are the same, and the third directional cartridge valve 17 is in the closed state. The A port and the T port of the second three-position four-way solenoid valve 18 are connected. At this time, the oil pressure of the pilot control oil of the A port and the C port of the second directional cartridge valve 16 is low pressure, and the oil pressure of the hydraulic oil of the B port is high pressure, and the A port and the B port of the second directional cartridge valve 16 can be connected. The hydraulic oil pumped by the pump oil assembly 1003 flows from the B port of the second directional cartridge valve 16 to the A port, and the hydraulic oil is supplied to the upper chamber of the oil cylinder 1 through the second directional cartridge valve 16.

[0095] When the YA3b end of the second three-position four-way solenoid valve 18 is in the energized state, the P port and the A port of the second three-position four-way solenoid valve 18 are connected, and the B port and the T port are connected. The hydraulic oil pumped by the oil pump assembly 1003 flows to the A port through the P port of the second three-position four-way solenoid valve 18, providing pilot control oil for the A port and the C port of the second directional cartridge valve 16. At this time, the pressures of the A port, the B port and the C port of the second directional cartridge valve 16 are the same, and the second directional cartridge valve 16 is in the closed state. The B port and the T port of the second three-position four-way solenoid valve 18 are connected. At this time, the oil pressure of the pilot control oil of the A port and the C port of the third directional cartridge valve 17 is low pressure, and the oil pressure of the hydraulic oil of the B port is high pressure. The hydraulic oil pumped by the oil pump assembly 1003 flows from the B port of the third directional cartridge valve 17 to the A port. The hydraulic oil is supplied to the lower chamber of the oil cylinder 1 through the third directional cartridge valve 17 or flows back to the oil tank 4 through the two-position two-way servo flow valve YAB.

[0096] Specifically, in this embodiment, the flow rate of the hydraulic oil supplied by the oil pump assembly 1003 to the upper chamber of the oil cylinder 1 is less than the flow rate of the hydraulic oil returned to the oil tank 4 through the filling valve 2. That is, the flow rate of the hydraulic oil in the second pipeline 51 is less than the flow rate in the first pipeline 50. When the pressure head drops quickly, the oil is quickly filled into the upper chamber through the filling valve 2. When the pressure head drops slowly, the filling valve 2 is closed, and the oil pump assembly 1003 supplies hydraulic oil to the upper chamber of the oil cylinder 1.

[0097] Preferably, a second electromagnetic ball valve cartridge valve group 20 is also provided on the second pipeline 51, and the second electromagnetic ball valve cartridge valve group 20 is provided between the diverter assembly 1002 and the lower chamber of the oil cylinder 1. The second electromagnetic ball valve cartridge valve group 20 includes a second two-position three-way electromagnetic valve YA5 and a fourth cartridge valve 201, the A port of the second directional cartridge valve 16 is connected to the A port of the fourth cartridge valve 201, the B port of the fourth cartridge valve 201 is connected to the upper chamber of the oil cylinder 1, the C port of the fourth cartridge valve 201 is connected to the A port of the second two-position three-way electromagnetic valve YA5, and the T port of the second two-position three-way electromagnetic valve YA5 is connected to the oil tank 4.

[0098] When the second two-position three-way solenoid valve YA5 is in a de-energized state, the A port of the second two-position three-way solenoid valve YA5 is connected to the B port. When the second two-position three-way solenoid valve YA5 is in an energized state, the A port of the second two-position three-way solenoid valve YA5 is connected to the T port, and the A port and the B port of the fourth cartridge valve 201 can be bidirectionally connected. Specifically, the flow direction of the hydraulic oil is determined according to the pressure of the hydraulic oil at the A port and the B port of the fourth cartridge valve 201.

[0099] Preferably, a second proportional relief valve YAA is also provided on the pipeline between the fourth cartridge valve 201 and the second directional cartridge valve 16, and the second proportional relief valve YAA is used to control the pressure of the hydraulic oil in the pipeline. When the pressure in the pipeline is greater than the second preset pressure value, the second proportional relief valve YAA opens to release the pressure. In this embodiment, the control voltage of the second proportional relief valve YAA is 0 to +10V, which can realize accurate closed-loop control of the pressure head pressure, and can control the pressure range of 10-315bar, and the control accuracy is ±1% of the rated pressure.

[0100] Preferably, a second pressure sensor 21 is provided on the pipeline between the lower chamber of the oil cylinder 1 and the fourth cartridge valve 201. The second pressure sensor 21 is used to detect the oil pressure of the hydraulic oil in the pipeline in real time and transmit the pressure to the electronic control component. When the pressure value in the pipeline is greater than the second preset pressure value, the electronic control component transmits the signal to the second proportional relief valve YAA, and the second proportional relief valve YAA opens to release the pressure.

[0101] Preferably, the oil pump assembly 1003 includes a servo motor 7 , a double metering pump 8 , a fourth directional cartridge valve 11 and a fifth directional cartridge valve 14 , and the servo motor 7 is connected to the double metering pump 8 .

[0102] The double-connected metering pump 8 is a double-connected internal gear pump, including a high-pressure pump and a low-pressure pump. The output shaft of the servo motor 7 is connected to the high-pressure pump and the low-pressure pump, and the servo motor 7 drives the high-pressure pump and the low-pressure pump to work. The high-pressure pump and the low-pressure pump constitute a main pump group, and the outlet of the high-pressure pump is connected to the A port of the fourth directional cartridge valve 11, and the B port and the C port of the fourth directional cartridge valve 11 are connected to the P port of the second three-position four-way solenoid valve 18, the B port of the second directional cartridge valve 16, and the B port of the third directional cartridge valve 17.

[0103] The outlet of the low-pressure pump is connected to the A port of the fifth directional cartridge valve 14 , and the B port and the C port of the fifth directional cartridge valve 14 are connected to the P port of the second three-position four-way solenoid valve 18 , the B port of the second directional cartridge valve 16 and the B port of the third directional cartridge valve 17 .

[0104] The oil pump assembly 1003 also includes a pressure relief assembly 1001, and the high-pressure pump and / or the low-pressure pump are connected to a group of pressure relief assemblies 1001. The pressure relief assembly 1001 includes a pressure cartridge valve, a relief valve, and a two-position four-way solenoid valve. The A port and the T port of the pressure cartridge valve are both connected to the outlet of the high-pressure pump, and / or, the A port and the T port of the pressure cartridge valve are both connected to the outlet of the low-pressure pump. The B port of the pressure cartridge valve is connected to the oil tank 4.

[0105] The port A of the relief valve is connected to the outlet of the high-pressure pump, and / or the port A of the relief valve is connected to the outlet of the low-pressure pump. The port T of the relief valve is connected to the oil tank 4.

[0106] The P port of the two-position four-way solenoid valve is connected to the outlet of the high-pressure pump, and / or, the P port of the two-position four-way solenoid valve is connected to the outlet of the low-pressure pump. The A port and the T port of the two-position four-way solenoid valve are both connected to the oil tank 4. The B port of the two-position four-way solenoid valve is a normally closed port.

[0107] Specifically, the pressure relief assembly 1001 connected to the high-pressure pump in this embodiment includes a first pressure cartridge valve 10, a third relief valve 36 and a first two-position four-way solenoid valve YA1. The pressure relief assembly 1001 connected to the low-pressure pump includes a second pressure cartridge valve 13, a fourth relief valve 37 and a second two-position four-way solenoid valve YA2. Among them, the A port and the T port of the first pressure cartridge valve 10 are both connected to the outlet of the high-pressure pump, and the B port of the first pressure cartridge valve 10 is connected to the oil tank 4. The A port of the third relief valve 36 is connected to the outlet of the high-pressure pump, and the T port of the third relief valve 36 is connected to the oil tank 4.

[0108] The P port of the first two-position four-way solenoid valve YA1 is connected to the outlet of the high-pressure pump, the A port and the T port of the first two-position four-way solenoid valve YA1 are both connected to the oil tank 4, and the B port is a normally closed port. When the first two-position four-way solenoid valve YA1 is in a power-off state, the P port is connected to the A port, and the B port is connected to the T port. When the first two-position four-way solenoid valve YA1 is in a power-on state, the P port is connected to the B port, and the A port is connected to the T port.

[0109] When the high-pressure pump starts pumping oil, when the first two-position four-way solenoid valve YA1 is in the energized state, the P port and the B port of the first two-position four-way solenoid valve YA1 are connected, the pressure of the C port of the fourth directional cartridge valve 11 is less than the pressure of the A port and the B port, the A port and the B port of the fourth directional cartridge valve 11 can flow in both directions, and the flow direction of the hydraulic oil is determined according to the pressure of the A port and the B port of the fourth directional cartridge valve 11.

[0110] When the pressure in the pipeline where the third overflow valve 36 is located is greater than the third preset pressure value, the pressure overflows back to the oil tank 4 through the third overflow valve 36. In this embodiment, the third preset pressure value is 21 MPa.

[0111] When the high-pressure pump continues to work, but there is no need to continue to supply oil to the pipeline where the second three-position four-way solenoid valve 18 is located, because the working pressure of the first pressure cartridge valve 10 is lower than the working pressure of the fourth directional cartridge valve 11, when the oil pump assembly 1003 pumps oil, the first pressure cartridge valve 10 opens to work, and the hydraulic oil flows from port A to port B of the first pressure cartridge valve 10 and flows back to the oil tank 4.

[0112] Similarly, port A and port T of the second pressure cartridge valve 13 are connected to the outlet of the low pressure pump, and port B of the fifth directional cartridge valve 14 is connected to the oil tank 4. Port A of the fourth relief valve 37 is connected to the outlet of the high pressure pump, and port T of the fourth relief valve 37 is connected to the oil tank 4.

[0113] The P port of the second two-position four-way solenoid valve YA2 is connected to the outlet of the high-pressure pump, the A port and the T port of the second two-position four-way solenoid valve YA2 are both connected to the oil tank 4, and the B port is a normally closed port. When the second two-position four-way solenoid valve YA2 is in a power-off state, the P port of the second two-position four-way solenoid valve YA2 is connected to the A port, and the B port is connected to the T port. When the second two-position four-way solenoid valve YA2 is in a power-on state, the P port is connected to the B port, and the A port is connected to the T port.

[0114] When the high-pressure pump starts to pump oil and the second two-position four-way solenoid valve YA2 is in the energized state, the P port and the B port of the second two-position four-way solenoid valve YA2 are connected, the pressure of the C port of the fifth directional cartridge valve 14 is less than the pressure of the A port and the B port, and the A port and the B port of the fifth directional cartridge valve 14 can flow in both directions. The flow direction of the hydraulic oil is determined according to the pressure of the A port and the B port of the fifth directional cartridge valve 14.

[0115] When the pressure in the pipeline where the fourth overflow valve 37 is located is greater than the fourth preset pressure value, the pressure overflows back to the oil tank 4 through the fourth overflow valve 37. In this embodiment, the fourth preset pressure value is 10 MPa.

[0116] When the low-pressure pump continues to work, but there is no need to continue to supply oil to the pipeline of the second three-position four-way solenoid valve 18, because the working pressure of the second pressure cartridge valve 13 is lower than the working pressure of the fifth directional cartridge valve 14, when the oil pump assembly 1003 pumps oil, the second pressure cartridge valve 13 opens to work, and the hydraulic oil flows from the A port of the second pressure cartridge valve 13 to the B port and returns to the oil tank 4.

[0117] Preferably, a third pressure sensor 38 is further provided on the pipeline between the fourth directional cartridge valve 11 and the second three-position four-way solenoid valve 18. The third pressure sensor 38 is used to detect the pressure in the pipeline in real time and transmit the pressure to the electronic control component, which transmits the signal to the third relief valve 36 or the fourth relief valve 37. The third relief valve 36 and / or the fourth relief valve 37 are operated according to the working state of the high-pressure pump and the low-pressure pump to relieve pressure.

[0118] Preferably, the hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment further includes a third two-position four-way solenoid valve YA6, and the P port of the third two-position four-way solenoid valve YA6 is connected to the B port and the C port of the fourth directional cartridge valve 11, that is, the P port of the third two-position four-way solenoid valve YA6 is also connected to the B port and the C port of the second directional cartridge valve 15. The A port of the third two-position four-way solenoid valve YA6 is in a normally closed state, the B port of the third two-position four-way solenoid valve YA6 is connected to the pilot control oil port of the filling valve 2, and the T port of the third two-position four-way solenoid valve YA6 is connected to the oil tank 4. When the third two-position four-way solenoid valve YA6 is powered off, the B port and the T port of the third two-position four-way solenoid valve YA6 are connected.

[0119] Preferably, a superimposed one-way throttle valve 26 is also provided on the pipeline between the third two-position four-way solenoid valve YA6 and the pilot control oil port of the filling valve 2. The superimposed one-way throttle valve 26 only allows the hydraulic oil to flow from the third two-position four-way solenoid valve YA6 to the pilot control oil port of the filling valve 2, and can automatically adjust the resistance coefficient according to the working conditions in the pipeline to keep the flow in the pipeline stable. The superimposed one-way throttle valve 26 is an existing product and can be selected according to actual needs.

[0120] Preferably, the hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment further includes an accumulator assembly 200, which includes an auxiliary oil pump assembly 32, an accumulator 30, and an accumulator control assembly 31. The outlet of the auxiliary oil pump assembly 32 is connected to the accumulator control assembly 31, and the accumulator control assembly 31 is connected to the accumulator 30. The auxiliary oil pump assembly 32 can supply oil to the accumulator 30 through the accumulator control assembly 31;

[0121] The accumulator control assembly 31 is connected to the P port of the first three-position four-way solenoid valve 231 . The accumulator 30 can supply oil to the P port of the first three-position four-way solenoid valve 231 through the accumulator control assembly 31 .

[0122] Preferably, the hydraulic system for the ram movement of the large-tonnage superplastic forming equipment further includes a filter assembly 41, which is disposed on the pipeline between the accumulator control assembly 31 and the P port of the first three-position four-way solenoid valve 231. The filter assembly 41 is used to filter the hydraulic oil in the pipeline.

[0123] Preferably, the auxiliary pump oil assembly 32 includes an auxiliary motor 5, an auxiliary pump 6 and an electromagnetic unloading valve 28. The output shaft of the auxiliary motor 5 is connected to the auxiliary pump 6. The auxiliary motor 5 drives the auxiliary pump 6 to work. The outlet of the auxiliary pump 6 is connected to the connection port of the accumulator control assembly 31. The auxiliary pump 6 can supply oil to the accumulator.

[0124] The electromagnetic unloading valve 28 is arranged on the fourth pipeline 54 between the accumulator control assembly 31 and the auxiliary pump 6. The electromagnetic unloading valve 28 limits the one-way flow of hydraulic oil from the auxiliary pump 6 to the accumulator control assembly 31. At the same time, the electromagnetic unloading valve 28 is used to control the oil pressure of the hydraulic oil in the fourth pipeline. When the pressure in the pipeline where the auxiliary pump 6 is located is greater than the sixth preset pressure value, the pressure is released through the electromagnetic unloading valve 28. The sixth preset pressure value in this embodiment is 16MPa. In this embodiment, the specific structure of the electromagnetic unloading valve 28 is as follows: Figure 1 As shown, this structure is an existing product on the market and can be used selectively according to needs.

[0125] The accumulator control assembly 31 includes a fifth relief valve 311, a normally closed switch 312, and a normally open switch 313. The fifth relief valve 311, the normally closed switch 312, and the normally open switch 313 are arranged in parallel. The outlet of the normally closed switch 312 is connected to the oil tank 4. When the normally closed switch 312 is opened, the hydraulic oil in the accumulator 30 flows back to the oil tank 4. The hydraulic oil in the oil tank 4 is pumped to the accumulator 30 through the normally open switch 313.

[0126] The hydraulic oil in the accumulator 30 often flows to the filter assembly 41 after the switch 313 is turned on, and after being filtered by the filter assembly 41, the hydraulic oil is supplied to the P port of the first three-position four-way solenoid valve 231. The hydraulic oil in the accumulator 30 will not flow back to the auxiliary pump 6 due to the electromagnetic unloading valve 28.

[0127] The fifth relief valve 311 is used to control the pressure in the accumulator 30. The pressure in the accumulator 30 is adapted to the control pressure of the pilot control oil of the two-position two-way servo flow valve YAB.

[0128] When the pressure of the accumulator 30 is greater than the fifth preset pressure value, the fifth relief valve 311 opens to release the pressure. In this embodiment, the fifth preset pressure value is 10 MPa, 12 MPa or 16 MPa.

[0129] A fourth pressure sensor 40 is also provided on the pipeline between the filter assembly 41 and the first three-position four-way solenoid valve 231. The fourth pressure sensor 40 is used to detect the pressure in the pipeline in real time and transmit the pressure to the electronic control assembly, which transmits the signal to the fifth overflow valve 311.

[0130] The working process of the hydraulic system for the movement of the ram of the above-mentioned large-tonnage superplastic forming equipment is as follows:

[0131] The pressure head moves downward quickly, and the two-position two-way servo flow valve YAB and the first two-position three-way solenoid valve YA4 are both in the energized state. When the pressure head moves downward quickly, the filling valve 2 opens under the vacuum of the upper chamber of the oil cylinder 1, and the hydraulic oil quickly enters the upper chamber of the oil cylinder 1 through the filling valve 2. The hydraulic oil in the lower chamber flows to the A port through the B port of the first directional cartridge valve 241, and flows to the B port through the A port of the two-position two-way servo flow valve YAB, and flows back to the oil tank 4.

[0132] When the pressure head slowly drops, the two-position two-way servo flow valve YAB and the first two-position three-way solenoid valve YA4 are in the energized state, and the first two-position four-way solenoid valve YA1 and the second three-position four-way solenoid valve 18's YA3a end are both in the energized state. At this time, after the high-pressure pump pumps oil, it flows to the B port through the A port of the fourth directional cartridge valve 11, the P port of the second three-position four-way solenoid valve 18 flows to the B port, the B port of the second directional cartridge valve 16 flows to the A port, and the A port of the fourth cartridge valve 201 flows to the B port, and flows to the upper chamber of the oil cylinder 1.

[0133] When the pressure head returns, the second two-position four-way solenoid valve YA2 and the third two-position four-way solenoid valve YA6 are both in the energized state. After the low-pressure pump pumps oil, it flows to the B port through the A port of the fifth directional cartridge valve 14, the P port of the two-position four-way solenoid valve 27 flows to the B port, and the superimposed one-way throttle valve 26, and flows to the pilot control oil port of the filling valve 2, and enters the pilot control chamber of the filling valve 2. The filling valve 2 has a pre-discharge function, which can first unload the high pressure and open the filling valve 2, which generally takes 1-2 seconds. The opening time of the filling valve 2 can be adjusted by adjusting the speed of the servo motor 7 and the opening of the superimposed one-way throttle valve 26 to prevent hydraulic shock or too long opening time.

[0134] After that, when the first two-position four-way solenoid valve YA1 is in the energized state and the YA3b end of the second three-position four-way solenoid valve 18 is in the energized state, the high-pressure pump and the low-pressure pump of the double-connected quantitative pump 8 both pump oil, and after the pump oil of the two merges, it flows to the A port through the B port of the third directional cartridge valve 17, and flows to the B port of the first directional cartridge valve 241, and flows to the lower chamber of the oil cylinder 1. The hydraulic oil in the upper chamber of the oil cylinder 1 flows back to the oil tank 4 through the filling valve 2. The return speed of the pressure head is controlled by the servo motor.

[0135] The control process of the servo flow valve group 23 is as follows: the hydraulic oil in the accumulator 30 often opens the switch 313 to flow to the filter assembly 41, and flows to the first pilot control oil port P1 and the second pilot control oil port P2 of the two-position two-way servo flow valve YAB through the first three-position four-way solenoid valve 231 to realize pilot control. When the pressure value detected by the fourth pressure sensor 40 is lower than 12MPa, the two-position two-way solenoid valve YA7 in the electromagnetic unloading valve 28 is in the energized state, and the auxiliary pump 6 replenishes oil into the accumulator 30. When the pressure value detected by the fourth pressure sensor 40 reaches 16MPa, the two-position two-way solenoid valve YA7 of the electromagnetic unloading valve 28 is in the de-energized state, the auxiliary pump 6 stops supplying oil to the accumulator 30, and the oil flows back to the oil tank 4 to realize dry circulation.

[0136] In this embodiment, a servo motor 7 is used to drive the dual quantitative pump 8 to work. The high-pressure pump is used to supply oil for the slow downward movement of the pressure head, and the high-pressure pump and the low-pressure pump are used to supply oil simultaneously for the fast return movement of the pressure head, which can save motor power and reduce costs.

[0137] The servo motor 7 is used as the power source to drive the double quantitative pump 8. The speed of the servo motor 7 can be controlled in real time according to the movement speed of the pressure head to adjust the output flow of the pump. When the pressure head does not move, the servo motor 7 does not work and does not consume energy, thereby achieving the purpose of precise control and energy saving and environmental protection.

[0138] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A hydraulic system for the movement of a large-tonnage superplastic forming equipment ram, characterized in that: It comprises an oil tank (4), a pump drive assembly (100), a filling valve (2), an oil cylinder (1), a servo flow valve group (23) and an electric control assembly, wherein the pump drive assembly (100) and the servo flow valve group (23) are both electrically connected to the electric control assembly; The filling valve (2) is installed on the first pipeline (50) between the upper chamber of the oil cylinder (1) and the oil tank (4); The outlet of the pump drive assembly (100) is connected to the upper chamber of the oil cylinder (1) via a second pipeline (51), and the inlet of the pump drive assembly (100) is connected to the oil tank (4); The servo flow valve group (23) comprises a two-position two-way servo flow valve (YAB) and a first three-position four-way solenoid valve (231); the port A of the two-position two-way servo flow valve (YAB) is connected to the lower chamber of the oil cylinder (1) via a third pipeline (53); and the port B of the two-position two-way servo flow valve (YAB) is connected to the oil tank (4); The A port of the first three-position four-way solenoid valve (231) is connected to the first pilot control oil port P1 of the two-position two-way servo flow valve (YAB), the B port of the first three-position four-way solenoid valve (231) is connected to the second pilot control oil port P2 of the two-position two-way servo flow valve (YAB), the T port of the first three-position four-way solenoid valve (231) is connected to the oil tank (4), and the P port of the first three-position four-way solenoid valve (231) is connected to external control oil; Either the A port or the B port of the first three-position four-way solenoid valve (231) is connected to the P port to control the opening of the two-position two-way servo flow valve (YAB).

2. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 1 is characterized in that: The third pipeline (53) is provided with a first electromagnetic ball valve cartridge valve assembly (24); The first electromagnetic ball valve cartridge valve assembly (24) comprises a first two-position three-way electromagnetic valve (YA4) and a first directional cartridge valve (241), and the B port of the first two-position three-way electromagnetic valve (YA4) and the B port of the first directional cartridge valve (241) are both connected to the lower chamber of the oil cylinder (1); The A port of the first two-position three-way solenoid valve (YA4) is connected to the C port of the first directional cartridge valve (241); The T port of the first two-position three-way solenoid valve (YA4) is connected to the oil tank (4); The port A of the first directional cartridge valve (241) is simultaneously connected to the port A of the two-position two-way servo flow valve (YAB) and the outlet of the pump drive assembly (100).

3. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 2 is characterized in that: The pump drive assembly (100) comprises an oil pump assembly (1003) and a flow splitter assembly (1002) arranged on the second pipeline (51); The flow diversion component (1002) comprises a second directional cartridge valve (16), a third directional cartridge valve (17) and a second three-position four-way solenoid valve (18); The outlet of the oil pump assembly (1003) is simultaneously connected to the P port of the second three-position four-way solenoid valve (18), the B port of the second directional cartridge valve (16), and the B port of the third directional cartridge valve (17); The T port of the second three-position four-way solenoid valve (18) is connected to the oil tank (4), the C port and the A port of the second directional cartridge valve (16) are simultaneously connected to the A port of the second three-position four-way solenoid valve (18), and the A port of the second directional cartridge valve (16) is connected to the upper chamber of the oil cylinder (1); Port A and port C of the third directional cartridge valve (17) are simultaneously connected to port B of the second three-position four-way solenoid valve (18); The A port of the third directional cartridge valve (17) is also connected to the A port of the two-position two-way servo flow valve (YAB).

4. The hydraulic system for the movement of the ram of a large-tonnage superplastic forming equipment according to claim 3 is characterized in that: The second pipeline (51) is also provided with a second electromagnetic ball valve cartridge valve assembly (20); The second electromagnetic ball valve cartridge valve assembly (20) comprises a second two-position three-way electromagnetic valve (YA5) and a fourth cartridge valve (201), and the port A of the second directional cartridge valve (16) is connected to the port A of the fourth cartridge valve (201); Port B of the fourth cartridge valve (201) is connected to the upper chamber of the oil cylinder (1); Port C of the fourth cartridge valve (201) is connected to port A of the second two-position three-way solenoid valve (YA5); The T port of the second two-position three-way solenoid valve (YA5) is connected to the oil tank (4).

5. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 4, characterized in that: A second proportional relief valve (YAA) is also provided between the fourth cartridge valve (201) and the second directional cartridge valve (16), and the second proportional relief valve (YAA) is used to control the pressure of the hydraulic oil in the pipeline.

6. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 5, characterized in that: The oil pump assembly (1003) comprises a servo motor (7), a double metering pump (8), a fourth direction cartridge valve (11) and a fifth direction cartridge valve (14), wherein the servo motor (7) is connected to the double metering pump (8); The double metering pump (8) comprises a high-pressure pump and a low-pressure pump, and the outlet of the high-pressure pump is connected to the port A of the fourth directional cartridge valve (11); Port B and port C of the fourth directional cartridge valve (11) are connected to port P of the second three-position four-way solenoid valve (18), port B of the second directional cartridge valve (16) and port B of the third directional cartridge valve (17); The outlet of the low-pressure pump is connected to the port A of the fifth directional cartridge valve (14); Port B and port C of the fifth directional cartridge valve (14) are both connected to port P of the second three-position four-way solenoid valve (18), port B of the second directional cartridge valve (16) and port B of the third directional cartridge valve (17).

7. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 6, characterized in that: The oil pump assembly (1003) further comprises a pressure relief assembly (1001), the high-pressure pump is connected to the pressure relief assembly (1001), and / or the low-pressure pump is connected to the pressure relief assembly (1001); The pressure relief assembly (1001) comprises a pressure cartridge valve, a relief valve and a two-position four-way solenoid valve; The A port and the T port of the pressure cartridge valve are connected to the outlet of the high-pressure pump, and / or the A port and the T port of the pressure cartridge valve are connected to the outlet of the low-pressure pump; Port B of the pressure cartridge valve is connected to the oil tank (4); The port A of the relief valve is connected to the outlet of the high-pressure pump, and / or the port A of the relief valve is connected to the outlet of the low-pressure pump; The T port of the overflow valve is connected to the oil tank (4); The P port of the two-position four-way solenoid valve is connected to the outlet of the high-pressure pump, and / or the P port of the two-position four-way solenoid valve is connected to the outlet of the low-pressure pump; The A port and the T port of the two-position four-way solenoid valve are both connected to the oil tank (4), and the B port of the two-position four-way solenoid valve is a normally closed port.

8. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 7, characterized in that: The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment further comprises a third two-position four-way solenoid valve (YA6), the P port of the third two-position four-way solenoid valve (YA6) being connected to the B port and the C port of the fourth directional cartridge valve (11), and the A port of the third two-position four-way solenoid valve (YA6) being in a normally closed state; The B port of the third two-position four-way solenoid valve (YA6) is connected to the pilot control oil port of the filling valve (2), and the T port of the third two-position four-way solenoid valve (YA6) is connected to the oil tank (4).

9. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 8, characterized in that: The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment further comprises an accumulator assembly (200), wherein the accumulator assembly (200) comprises an auxiliary pump oil assembly (32), an accumulator (30) and an accumulator control assembly (31); The outlet of the auxiliary oil pump assembly (32) is connected to the energy accumulator control assembly (31), the energy accumulator control assembly (31) is connected to the energy accumulator (30), and the auxiliary oil pump assembly (32) can supply oil to the energy accumulator (30) through the energy accumulator control assembly (31); The accumulator control component (31) is connected to the P port of the first three-position four-way solenoid valve (231), and the accumulator (30) can supply oil to the P port of the first three-position four-way solenoid valve (231) through the accumulator control component (31).

10. The hydraulic system for the movement of the ram of the large-tonnage superplastic forming equipment according to claim 9, characterized in that: The auxiliary pump oil assembly (32) comprises an auxiliary motor (5), an auxiliary pump (6) and an electromagnetic unloading valve (28), the output shaft of the auxiliary motor (5) is connected to the auxiliary pump (6), and the outlet of the auxiliary pump (6) is connected to the connection port of the energy storage device control assembly (31); The electromagnetic unloading valve (28) is arranged on a fourth pipeline (54) between the energy accumulator control component (31) and the auxiliary pump (6); The electromagnetic unloading valve (28) limits the one-way flow of hydraulic oil from the auxiliary pump (6) to the accumulator control assembly (31); Furthermore, the electromagnetic unloading valve (28) is used to control the oil pressure of the hydraulic oil in the fourth pipeline (54).

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