CN114670471B

CN114670471B - Composite material product thermoforming servo hydraulic press and method for pressing composite material civil air defense airtight door by using same

Info

Publication number: CN114670471B
Application number: CN202210305826.3A
Authority: CN
Inventors: 乔礼惠
Original assignee: Jiangsu Yangli Hydraulic Equipment Co ltd
Current assignee: Jiangsu Yangli Hydraulic Equipment Co ltd
Priority date: 2022-03-25
Filing date: 2022-03-25
Publication date: 2024-02-06
Anticipated expiration: 2042-03-25
Also published as: CN114670471A

Abstract

The invention discloses a hot forming servo hydraulic press for a composite material product and a method for pressing the composite material civil air defense airtight door by the hot forming servo hydraulic press. The method comprises the following steps: heating the upper die and the lower die, cutting and weighing the sheet, putting the sheet into the lower die, starting a motor, quickly descending a sliding block, slowly descending the sliding block, leveling the sliding block by each leveling die opening cylinder, pressurizing, maintaining pressure, releasing pressure, opening the die for set times, and returning the sliding block. The invention can press large-area air-proof airtight door, and has even pressing force and good product quality.

Description

Composite material product thermoforming servo hydraulic press and method for pressing composite material civil air defense airtight door by using same

Technical Field

The invention relates to a hydraulic machine, in particular to a hot forming servo hydraulic machine for a composite material product; the invention further relates to a method for pressing the composite material civil air defense airtight door by the hydraulic machine, and belongs to the technical field of hydraulic machine tools.

Background

With the progress of urbanization, more civil defense projects are put into construction. The air-proof door belongs to a safety protection door, is mainly applied to an access part of an underground shelter, is provided with the underground shelter in a newly built residential district or public place at present, and can be used as an underground garage in a peace construction period. Once the war is exploded, the air-tight door can be used for protecting the shock wave of the conventional weapon and various chemical toxicants, protecting the life safety of personnel and reducing the loss caused by the war.

The existing civil air defense airtight door is manufactured by adopting a high-strength thick steel plate, is easy to rust due to the influence of moisture because of being installed underground, has high maintenance cost, and is particularly important in the current international situation of changing phantom mode because the national research is started to adopt new materials and new technologies to manufacture the airtight door with the same or higher strength.

Five units are just wholesale in the country for a long time to develop and trial manufacture, and the trial manufactured products have the following problems: 1. the structure is simple, the pressing tonnage is low, the density of the airtight door is low, and the requirement of explosion protection and impact protection at a higher level cannot be met;

2. The new technology of the new material requires that the liquid filling valve is opened quickly when the machine tool is closed and pressurized quickly and returned, and the conventional liquid filling valve is opened and closed not fast enough and unstable;

3. the layout of the conventional main oil cylinder and pull rod is easy to generate stress concentration and fatigue damage under the action of periodic cyclic load;

4. because the area of the air-proof airtight door is relatively large, the area of the workbench and the cross section area of the sliding block are overlarge as the area of the air-proof airtight door can reach more than 3m multiplied by 2.5m normally. At present, according to the national requirements on trial-manufactured products, the area of a required working table of a common civil air defense airtight door reaches 5.8mX4.8m; the area of the required workbench of the large-scale air-defense airtight door reaches 7m multiplied by 4.8m, so that the cross section area of the sliding block is very large. Under the pressing of more than ten thousand tons of pressure, the composite material flows in the cavity after the die assembly to be filled in the cavity and then is formed by heating, so that the sliding block bears a large overturning moment, and is easy to incline or unbalanced load.

Disclosure of Invention

The primary aim of the invention is to overcome the problems in the prior art, and provide a hot forming servo hydraulic press for composite material products, which can press large-area air-defense airtight doors, the pressing tonnage can reach over ten thousand tons, the pressing force is uniform, and the high requirements of the air-defense airtight doors on density, thickness and external dimensions can be met.

In order to solve the technical problems, the hot forming servo hydraulic press for the composite material product comprises a machine body, wherein the machine body comprises a workbench and an upper cross beam which are parallel to each other, upright posts are respectively arranged between four corners of the workbench and the upper cross beam, a heating lower die is arranged on the workbench, a heating upper die is arranged at the bottom of the sliding block, four pull rods are respectively arranged in each upright post to fixedly connect the workbench and the upper cross beam, the sliding block is arranged between the upper cross beam and the workbench, a plurality of main oil cylinders are arranged in the upper cross beam and are uniformly distributed in a rectangular array, the lower ends of plungers of the main oil cylinders are respectively fixedly connected with the sliding block, sliding block lug seats are respectively fixed in the middle parts of the left side and the right side of the sliding block, the sliding block lug seats are respectively connected with the upper ends of plungers of return cylinders, and the cylinder body of the return cylinders are respectively fixed on the workbench and are positioned in the middle parts between the front upright post and the rear upright posts.

As an improvement of the invention, leveling die-sinking cylinders are symmetrically arranged on the front side and the rear side of the two return cylinders respectively, the cylinder bodies of the leveling die-sinking cylinders are fixed on the workbench, and the plunger tops of the leveling die-sinking cylinders are positioned below the die-sinking supporting lugs of the sliding blocks.

As a further improvement of the invention, sixteen main cylinders are arranged in the upper cross beam and are uniformly arranged in four rows and four columns.

As a further improvement of the invention, the upper cavity oil port of each main oil cylinder is respectively connected with an upper oil tank through a liquid filling valve, the lower liquid control port of each liquid filling valve is respectively connected with a liquid filling valve lower control oil path AK, the upper liquid control port of each liquid filling valve is respectively connected with a liquid filling valve upper control oil path BK, and the upper cavity oil port of each main oil cylinder is also respectively connected with a main oil cylinder oil path PC1 through a main oil cylinder control valve group; the oil ports of the lower cavities of the two return cylinders are connected with a main pressure oil circuit through a return control valve group; and the oil ports of the lower cavities of the leveling die-sinking cylinders are respectively connected with a main pressure oil circuit through a die-sinking control valve group.

As a further improvement of the invention, the inlets of the cartridge valve C51 and the cartridge valve C52 are respectively connected with a main pressure oil way, the outlet of the cartridge valve C51 is connected with the inlet of the cartridge valve C50, and the outlet of the cartridge valve C50 is connected with the main oil cylinder oil way PC 1; the outlet of the cartridge valve C52 is connected with a lower oil tank of the hydraulic system;

the hydraulic control port of the cartridge valve C51 is connected with the A port of the electromagnetic directional valve YA26, the P port of the electromagnetic directional valve YA26 is connected with a main pressure oil way, and the T port of the electromagnetic directional valve YA26 is connected with a lower oil tank;

The hydraulic control port of the cartridge valve C52 is connected with the A port of the electromagnetic directional valve YA27, the P port of the electromagnetic directional valve YA27 is connected with a main pressure oil way, and the T port of the electromagnetic directional valve YA27 is connected with a lower oil tank; the electromagnetic directional valve YA26 and the electromagnetic directional valve YA27 are two-position four-way electromagnetic directional valves.

As a further improvement of the invention, the inlet of the cartridge valve C53 is connected with a main pressure oil way, the outlet of the cartridge valve C53 is connected with the accumulator AC1 and the inlet of the cartridge valve C54 through a one-way valve D1, the outlet of the cartridge valve C54 is connected with the P port of the electro-hydraulic reversing valve YA23, the T port of the electro-hydraulic reversing valve YA23 is connected with an oil tank, the A port of the electro-hydraulic reversing valve YA23 is connected with the lower control oil way AK of the liquid filling valve, and the B port of the electro-hydraulic reversing valve YA23 is connected with the upper control oil way BK of the liquid filling valve;

the hydraulic control port of the cartridge valve C53 is connected with the A port of the electromagnetic directional valve YA25, the P port of the electromagnetic directional valve YA25 is connected with a main pressure oil way, and the T port of the electromagnetic directional valve YA25 is connected with a lower oil tank;

the hydraulic control port of the cartridge valve C54 is connected with the A port of the electromagnetic ball valve YA24, the P port of the electromagnetic ball valve YA24 is connected with the outlet of the cartridge valve C54, the T port of the electromagnetic ball valve YA24 is connected with a lower oil tank, and the outlet of the cartridge valve C54 is also connected with the lower oil tank through a pressure regulating valve F27;

the electro-hydraulic reversing valve YA23 and the electromagnetic reversing valve YA25 are two-position four-way electromagnetic reversing valves, and the electromagnetic ball valve YA24 is a two-position three-way electromagnetic ball valve.

As a further improvement of the invention, the upper cavity oil ports of the four adjacent main cylinders are controlled by the same group of main cylinder control valve groups, the first main cylinder control valve group comprises a cartridge valve C42 and a proportional overflow valve YAA, the inlet of the cartridge valve C42 is connected with the main cylinder oil path PC1, the outlet of the cartridge valve C42 is connected with the upper cavity oil ports of the main cylinders of the group and the B port of the proportional overflow valve YAA, and the A port of the proportional overflow valve YAA is connected with an oil tank;

the hydraulic control port of the cartridge valve C42 is connected with the middle port of the shuttle valve S1, the left inlet of the shuttle valve S1 is connected with the outlet of the cartridge valve C42, the right inlet of the shuttle valve S1 is connected with the A port of the electromagnetic directional valve YA15, the P port of the electromagnetic directional valve YA15 is connected with the main oil cylinder oil way PC1, and the rest main oil cylinder control valve groups are analogized;

the outlet of the servo pump P15 is connected with the oil port of the accumulator AC2 through a one-way valve D2, and the oil port of the accumulator AC2 is also connected with the control port of the proportional relief valve YAA of the first main cylinder control valve group and the control ports of the proportional relief valves of the other main cylinder control valve groups through control oil paths.

As a further improvement of the invention, the return control valve group comprises cartridge valves C29 to C33, wherein the inlet of the cartridge valve C31 is connected with a main pressure oil path, the outlet of the cartridge valve C31 is connected with the inlets of the cartridge valve C29, the cartridge valve C32 and the cartridge valve C33, the outlet of the cartridge valve C29 is connected with the outlet of the cartridge valve C30 and the lower cavity oil ports of the return cylinders, the inlet of the cartridge valve C30 is connected with a lower oil tank, and the outlets of the cartridge valve C32 and the cartridge valve C33 are connected with a lower oil tank;

The hydraulic control port of the cartridge valve C29 is connected with the A port of the electromagnetic ball valve YA29, the P port of the electromagnetic ball valve YA29 is connected with the outlet of the cartridge valve C29, and the T port of the electromagnetic ball valve YA29 is connected with the lower oil tank;

the hydraulic control port of the cartridge valve C31 is connected with the middle port of the shuttle valve S2, the left inlet of the shuttle valve S2 is connected with the outlet of the cartridge valve C31, the right inlet of the shuttle valve S2 is connected with the A port of the electromagnetic directional valve YA28, the P port of the electromagnetic directional valve YA28 is connected with a main pressure oil way, and the T port of the electromagnetic directional valve YA28 is connected with an oil tank;

the hydraulic control port of the cartridge valve C32 is connected with the A port of the electromagnetic directional valve YA30, the P port of the electromagnetic directional valve YA30 is connected with the inlet of the cartridge valve C32, and the T port of the electromagnetic directional valve YA30 is connected with the lower oil tank;

the hydraulic control port of the cartridge valve C33 is connected with the P port of the electromagnetic directional valve YA31, the pressure regulating valve F16 and the inlet of the pressure regulating valve F17, the outlet of the pressure regulating valve F16 is connected with the A port of the electromagnetic directional valve YA31, and the T port of the electromagnetic directional valve YA31 and the outlet of the pressure regulating valve F17 are connected with the oil tank;

the electromagnetic ball valve YA29 is a two-position three-way electromagnetic ball valve, and the electromagnetic directional valve YA28, the electromagnetic directional valve YA30 and the electromagnetic directional valve YA31 are two-position four-way electromagnetic directional valves.

As a further improvement of the invention, the die opening control valve group comprises first to fourth die opening control valve groups, the first die opening control valve group comprises a cartridge valve C34 and a cartridge valve C35, the inlet of the cartridge valve C35 is connected with a main pressure oil way, the outlet of the cartridge valve C35 is connected with a lower cavity oil port of the leveling die opening cylinder I and the inlet of the cartridge valve C34, and the outlet of the cartridge valve C34 is connected with a lower oil tank;

The hydraulic control port of the cartridge valve C34 is connected with the inlet of the pressure regulating valve F18, the control port of the pressure regulating valve F18 is connected with the oil tank through the remote pressure regulating valve F19, the outlet of the pressure regulating valve F18 is connected with the port B of the electromagnetic directional valve YA32, the hydraulic control port of the cartridge valve C35 is connected with the port A of the electromagnetic directional valve YA32, the port P of the cartridge electromagnetic directional valve YA32 is connected with the outlet of the cartridge valve C35, the port T of the electromagnetic directional valve YA32 is connected with the oil tank, and the electromagnetic directional valve YA32 is a two-position four-way electromagnetic directional valve; and the hydraulic circuits from the second valve group to the fourth valve group are opened, and so on.

As a further improvement of the invention, the heating lower die is provided with a process cylinder for processing a process hole of a pressed product, a main pressure oil way is connected with a P port of a three-position four-way electromagnetic reversing valve through a pressure regulating valve F26, a T port of the three-position four-way electromagnetic reversing valve is connected with an oil tank, an A port of the three-position four-way electromagnetic reversing valve is connected with a lower cavity oil port of the process cylinder, a B port of the three-position four-way electromagnetic reversing valve is connected with an upper cavity oil port of the process cylinder, and the middle position function of the three-position four-way electromagnetic reversing valve is Y-shaped.

The invention further aims to overcome the problems in the prior art and provide a method for pressing the composite material civil air defense airtight door by the hydraulic machine, wherein the pressing tonnage can reach over ten thousand tons, the pressing force is uniform, and the high requirements of the civil air defense airtight door on density, thickness and external dimension can be met.

In order to solve the technical problems, the method for pressing the composite material civil air defense airtight door by the hydraulic press sequentially comprises the following steps:

step 1: heating the upper heating die below the sliding block and the lower heating die above the workbench to 150-180 ℃;

step 2: cutting the composite material mould pressing sheet, and weighing to confirm that the composite material mould pressing sheet meets the design weight;

step 3: placing the composite molded sheet into a mold cavity of a heated lower mold;

step 4: starting a motor of each servo pump;

step 5: the sliding block rapidly descends;

step 6: the sliding block slowly descends, the die opening support lugs at the four corners of the sliding block respectively lean against the upper ends of the plungers of the corresponding leveling die opening cylinders, and the sliding block is leveled in the forced withdrawal process of the plungers of the leveling die opening cylinders so as to avoid inclination;

step 7: pressurizing the sliding block;

step 8: maintaining pressure of the sliding block;

step 9: the sliding block is depressurized;

step 10: opening a die; and then repeatedly executing the steps 6 to 10 according to the times set by the process until the last mold opening is completed;

step 11: the sliding block rapidly returns;

step 12: the sliding block returns slowly.

As an improvement of the invention, the process cylinder is ejected out during the first pressure maintaining; and after the last pressure maintaining is finished, the process cylinder retreats and releases pressure, and a process hole is left on the composite material product.

Compared with the prior art, the invention has the following beneficial effects: 1. the electro-hydraulic reversing valve YA23 with the DG25 diameter is combined with the accumulator AC1, so that the initiative, the rapidness, the stability and the reliability of opening and closing of each liquid filling valve can be realized; the accumulator AC1 can realize the constant flow effect, the pipeline is filled with oil, the response time for opening or closing the liquid filling valve can be shortened, unified and rapid opening and rapid pressure building are realized, and the vortex noise is reduced;

2. four pull rods are arranged at each corner of the machine body part, sixteen pull rod structures are adopted, and meanwhile, a main oil cylinder adopts a sixteen-cylinder uniformly distributed mode, so that the problems of large table top of a machine tool and stress concentration of the machine body are solved; two return cylinders and four leveling die-sinking cylinders are symmetrically arranged by utilizing a neutral position between upright posts on two sides;

3. the composite material has transverse flow in the pressing process, so that the sliding block bears the overturning moment generated by the transverse flow, the sliding block is very easy to incline to influence the density and the dimensional accuracy of the product, and the condition that the sliding block is singly leaning on a four-corner octahedral guide rail is insufficient. The four leveling die-opening cylinders not only play a role in micro-die opening, but also play a role in leveling in the slow descending process, the pressures of the four leveling die-opening cylinders are respectively and independently set, the ejection heights are respectively controlled, the forming of special-shaped pieces is met, the position and pressure adjustment can be respectively carried out according to the density requirements of the parts, and the product yield is improved;

4. The pressure of the four main cylinders in one group can be separately set in groups, and can be respectively adjusted according to the density requirements of the parts, so that the product yield is improved;

5. the volume speed regulation of the hydraulic machine is realized by adopting a servo pump control technology, the speed regulation range of a servo motor is wide, and the process requires long-time pressure maintaining, so that energy conservation can be maximally realized;

6. the process requires long-time constant pressure and pressure maintaining, and by setting the operation mode of the servo pump with low rotation speed and high pressure, the flow output is reduced, the high pressure output is met, the high pressure overflow of oil is reduced, and the temperature rise of the oil is effectively reduced;

7. the process holes can be directly processed on the finished product of the composite material, the material density at the periphery of the process holes is higher, and the strength is enhanced.

Drawings

The invention will now be described in further detail with reference to the drawings and the detailed description, which are provided for reference and illustration only and are not intended to limit the invention.

FIG. 1 is a front view of a thermoforming servo hydraulic press of a composite article of the present invention;

FIG. 2 is a left side view of FIG. 1;

FIG. 3 is a top plan view of the present invention;

fig. 4 is a hydraulic schematic diagram of the present invention.

In the figure: 1. an upper cross beam; 2. a column; 3. a pull rod; 4. a master cylinder; 5. a return cylinder; 6. leveling and die opening cylinders; 7. a slide block; 7a, a sliding block ear seat; 8. a work table; 9. a process cylinder; 10. and a guide rail.

Detailed Description

In the following description of the present invention, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are merely for convenience in describing the present invention and simplifying the description, and do not mean that the device must have a specific orientation.

As shown in fig. 1 to 3, the hot forming servo hydraulic press for the composite material product comprises a machine body, wherein the machine body comprises a workbench 8 and an upper cross beam 1 which are parallel to each other, upright posts 2 are respectively arranged between four corners of the workbench 8 and the upper cross beam 1, a heating lower die is arranged on the workbench 8, a heating upper die is arranged at the bottom of a sliding block 7, four pull rods 3 are respectively arranged in each upright post 2 to fixedly connect the workbench 8 and the upper cross beam 1, the load born by each pull rod 3 is reduced, and stress concentration is prevented. A sliding block 7 is arranged between the upper cross beam 1 and the workbench 8, four corners of the sliding block 7 are respectively provided with a guide rail 10 which is mutually vertical, and each guide rail 10 is respectively fixed on a corresponding upright post to form a four-corner octahedral guide rail support of the sliding block 7.

A plurality of main oil cylinders 4 are uniformly distributed in the upper beam 1, the main oil cylinders 4 are uniformly distributed in a rectangular array, the lower ends of plungers of the main oil cylinders 4 are fixedly connected with the sliding blocks 7 respectively, the middle parts of the left side and the right side of the sliding blocks 7 are fixedly provided with sliding block lug seats 7a respectively, the sliding block lug seats 7a are connected with the upper ends of plungers of the return cylinders 5 respectively, and the cylinder bodies of the return cylinders 5 are fixed on the workbench 8 respectively and are positioned in the middle parts between the front upright posts 2 and the rear upright posts 2.

Leveling die opening cylinders 6 are symmetrically arranged on the front side and the rear side of the two return cylinders 5 respectively, cylinder bodies of the leveling die opening cylinders 6 are fixed on a workbench 8, the top of a plunger of each leveling die opening cylinder 6 is located below a die opening support lug, and the die opening support lugs are connected to corners of a sliding block or a heating upper die. When the die opening lugs of the sliding blocks are supported at the tops of the plungers of the corresponding leveling die opening cylinders 6, the sliding blocks 7 can be leveled, and skew or unbalanced load of the sliding blocks can be avoided. For special-shaped products, the die-opening lugs can be fixed on different heights of the upper die, so that the bottom plates of the die-opening lugs are positioned on the same horizontal plane, and the horizontal downward pressing of the sliding blocks 7 is also satisfied.

For the hydraulic press for pressing the air-defense airtight door, two types of common workbench surfaces are adopted, namely 5800mm multiplied by 4800mm and 7000mm multiplied by 4800mm, the maximum opening height of the sliding block 7 is 2800mm, and the sliding block stroke is 1800mm.

Sixteen main oil cylinders 4 are arranged in the upper beam 1 and are uniformly arranged in four rows and four columns, so that the pressing force is more uniform, and the problem of stress concentration is solved. The pressing force of each master cylinder 4 is more than 630 tons, and the total pressing force of sixteen master cylinders is more than ten thousand tons.

As shown in fig. 4, the upper cavity ports of the first group of four master cylinders 4 are respectively connected with the upper oil tank through filling valves CF1, CF2, CF3 and CF4, the upper cavity ports of the second group of four master cylinders 4 are respectively connected with the upper oil tank through filling valves CF5, CF6, CF7 and CF8, the upper cavity ports of the third group of four master cylinders 4 are respectively connected with the upper oil tank through filling valves CF9, CF10, CF11 and CF12, and the upper cavity ports of the third group of four master cylinders 4 are respectively connected with the upper oil tank through filling valves CF13, CF14, CF15 and CF 16.

The lower hydraulic control port of each liquid filling valve is respectively connected with the lower control oil way AK of the liquid filling valve, and the upper hydraulic control port of each liquid filling valve is respectively connected with the upper control oil way BK of the liquid filling valve. When the sliding block is quickly lowered, the upper control oil way BK of the liquid filling valves builds pressure, the upper hydraulic control ports of the liquid filling valves build pressure, and the liquid filling valves are actively opened at the same time; when the sliding block is slowly lowered, the lower control oil way AK of the liquid filling valves builds pressure, and the lower hydraulic control ports of the liquid filling valves build pressure to actively close the liquid filling valves.

The upper cavity oil ports of the main oil cylinders 4 are also connected with a main oil cylinder oil way PC1 through main oil cylinder control valve groups respectively, and when the sliding block descends slowly, the main oil cylinder oil way PC1 is used for injecting oil into the upper cavity of each main oil cylinder through the main oil cylinder control valve groups.

The lower cavity oil ports of the two return cylinders 5 are connected with a main pressure oil path PB1 through a return control valve group, and when the sliding block slowly descends and returns, the main pressure oil path PB1 supplies oil to the lower cavities of the two return cylinders 5 through the return control valve group.

The lower cavity oil ports of the leveling die sinking cylinders 6 are respectively connected with the main pressure oil way PB2 through die sinking control valve groups. When the sliding block descends slowly and the die is opened, each die opening control valve group respectively controls the pressure of the corresponding leveling die opening cylinder 6, and the sliding block is kept balanced.

The inlets of the cartridge valve C51 and the cartridge valve C52 are respectively connected with the main pressure oil path PA1, the outlet of the cartridge valve C51 is connected with the inlet of the cartridge valve C50, and the outlet of the cartridge valve C50 is connected with the main oil cylinder oil path PC 1; the outlet of the cartridge valve C52 is connected with a lower oil tank of the hydraulic system.

The hydraulic control port of the cartridge valve C51 is connected with the A port of the electromagnetic directional valve YA26, the P port of the electromagnetic directional valve YA26 is connected with the main pressure oil way PA2, the T port of the electromagnetic directional valve YA26 is connected with the lower oil tank, and the electromagnetic directional valve YA26 and the electromagnetic directional valve YA27 are two-position four-way electromagnetic directional valves. When the electromagnetic directional valve YA26 is energized, the cartridge valve C51 is opened, and the master pressure oil passage PA1 supplies oil to the master cylinder oil passage PC 1.

The hydraulic control port of the cartridge valve C52 is connected with the port A of the electromagnetic directional valve YA27, the port P of the electromagnetic directional valve YA27 is connected with the main pressure oil way PA2, and the port T of the electromagnetic directional valve YA27 is connected with the lower oil tank; the electromagnetic directional valve YA27 is a two-position four-way electromagnetic directional valve. When the electromagnetic reversing valve YA27 is powered on, a hydraulic control port of the cartridge valve C52 is opened, and the main pressure oil circuit PA1 is unloaded so that an oil return tank in a main pipeline is convenient to maintain and operate; when the electromagnetic directional valve YA27 is powered off, the cartridge valve C52 is closed, and the main pressure oil path PA1 is pressurized.

The inlet of the cartridge valve C53 is connected with the main pressure oil path PA1, and the outlet of the cartridge valve C53 is connected with the accumulator AC1 and the inlet of the cartridge valve C54 through the one-way valve D1. The hydraulic control port of the cartridge valve C53 is connected with the A port of the electromagnetic directional valve YA25, the P port of the electromagnetic directional valve YA25 is connected with the main pressure oil way PA2, the T port of the electromagnetic directional valve YA25 is connected with the lower oil tank, and the electromagnetic directional valve YA25 is a two-position four-way electromagnetic directional valve. When the electromagnetic directional valve YA25 is energized, the cartridge valve C53 is opened and the main pressure oil passage PA1 is charged to the accumulator AC 1.

The outlet of the cartridge valve C54 is connected with the P port of the electro-hydraulic reversing valve YA23, the T port of the electro-hydraulic reversing valve YA23 is connected with an oil tank, the A port of the electro-hydraulic reversing valve YA23 is connected with the lower control oil path AK of the liquid filling valve, the B port of the electro-hydraulic reversing valve YA23 is connected with the upper control oil path BK of the liquid filling valve, and the electro-hydraulic reversing valve YA23 is a two-position four-way electromagnetic reversing valve.

The hydraulic control port of the cartridge valve C54 is connected with the A port of the electromagnetic ball valve YA24, the P port of the electromagnetic ball valve YA24 is connected with the outlet of the cartridge valve C54, the T port of the electromagnetic ball valve YA24 is connected with a lower oil tank, the outlet of the cartridge valve C54 is also connected with the lower oil tank through a pressure regulating valve F27, and the electromagnetic ball valve YA24 is a two-position three-way electromagnetic ball valve.

When the electromagnetic ball valve YA24 is powered on, the cartridge valve C54 is opened, oil is supplied to the P port of the electro-hydraulic reversing valve YA23, and the pressure regulating valve F27 serves as a safety pressure valve to control the highest oil pressure of the outlet of the cartridge valve C54 to be 15MPa.

When the electro-hydraulic reversing valve YA23 is not electrified, the P port is communicated with the A port, the B port is communicated with the T port, the pressure of the lower control oil way AK of the liquid filling valve is built, the pressure of the lower hydraulic control port of each liquid filling valve is built, and the pressure of the upper control oil way BK of the liquid filling valve is relieved. When the electro-hydraulic reversing valve YA23 is electrified, the P port is communicated with the B port, the A port is communicated with the T port, the pressure of the lower control oil way AK of the liquid filling valve is relieved, the pressure of the upper control oil way BK of the liquid filling valve is built, and the pressure of the upper hydraulic control ports of the liquid filling valves is built.

The upper cavity oil ports of the four adjacent main cylinders are controlled by the same group of main cylinder control valve groups, the first main cylinder control valve group comprises a cartridge valve C42 and a proportional overflow valve YAA, the inlet of the cartridge valve C42 is connected with a main cylinder oil path PC1, the outlet of the cartridge valve C42 is connected with the upper cavity oil ports of all the main cylinders of the group and the port B of the proportional overflow valve YAA, and the port A of the proportional overflow valve YAA is connected with an oil tank;

the hydraulic control port of the cartridge valve C42 is connected with the middle port of the shuttle valve S1, the left inlet of the shuttle valve S1 is connected with the outlet of the cartridge valve C42, the right inlet of the shuttle valve S1 is connected with the A port of the electromagnetic directional valve YA15, and the P port of the electromagnetic directional valve YA15 is connected with the main oil cylinder oil way PC 1.

When the sliding block is fast or slow down, the electromagnetic directional valve YA15 is powered on, the cartridge valve C42 is opened, and pressure oil enters the upper cavity of the first group of four main cylinders. When the sliding block is depressurized, the proportional overflow valve YAA is powered on, the port B is communicated with the port A respectively, the upper cavities of the first group of four main cylinders are controlled by the proportional overflow valve YAA to control flow, and the flow is slowly depressurized to the lower oil tank. The rest main oil cylinder control valve groups are analogized.

The outlet of the servo pump P15 is connected with the oil port of the accumulator AC2 through a one-way valve D2, and the oil port of the accumulator AC2 is also connected with the control port of the proportional relief valve YAA of the first main cylinder control valve group and the control ports of the proportional relief valves of the other main cylinder control valve groups through control oil paths. The accumulator AC2 keeps the constant pressure of each control port of the proportional relief valve YAA, YAB, YAC, YAD.

The return control valve group comprises cartridge valves C29 to C33, the inlet of the cartridge valve C31 is connected with the main pressure oil way PB1, the outlet of the cartridge valve C31 is connected with the inlets of the cartridge valve C29, the cartridge valve C32 and the cartridge valve C33, the outlet of the cartridge valve C29 is connected with the outlet of the cartridge valve C30 and the lower cavity oil ports of the return cylinders, the inlet of the cartridge valve C30 is connected with the lower oil tank, and the outlets of the cartridge valve C32 and the cartridge valve C33 are connected with the lower oil tank.

The hydraulic control port of the cartridge valve C29 is connected with the A port of the electromagnetic ball valve YA29, the P port of the electromagnetic ball valve YA29 is connected with the outlet of the cartridge valve C29, the T port of the electromagnetic ball valve YA29 is connected with a lower oil tank, and the electromagnetic ball valve YA29 is a two-position three-way electromagnetic ball valve.

The hydraulic control port of the cartridge valve C31 is connected with the middle port of the shuttle valve S2, the left inlet of the shuttle valve S2 is connected with the outlet of the cartridge valve C31, the right inlet of the shuttle valve S2 is connected with the A port of the electromagnetic directional valve YA28, the P port of the electromagnetic directional valve YA28 is connected with the main pressure oil way PB1, the T port of the electromagnetic directional valve YA28 is connected with the oil tank, and the electromagnetic directional valve YA28 is a two-position four-way electromagnetic directional valve.

The hydraulic control port of the cartridge valve C32 is connected with the A port of the electromagnetic directional valve YA30, the P port of the electromagnetic directional valve YA30 is connected with the inlet of the cartridge valve C32, the T port of the electromagnetic directional valve YA30 is connected with the lower oil tank, and the electromagnetic directional valve YA30 is a two-position four-way electromagnetic directional valve.

The hydraulic control port of the cartridge valve C33 is connected with the P port of the electromagnetic directional valve YA31, the pressure regulating valve F16 and the inlet of the pressure regulating valve F17, the outlet of the pressure regulating valve F16 is connected with the A port of the electromagnetic directional valve YA31, and the T port of the electromagnetic directional valve YA31 and the outlet of the pressure regulating valve F17 are connected with the oil tank; the electromagnetic directional valve YA31 is a two-position four-way electromagnetic directional valve.

When the sliding block returns, the electromagnetic directional valve YA28 is powered on, the cartridge valve C31 is opened, and pressure oil enters the lower cavity of the return cylinder.

When the sliding block is fast and slow to lower, and is pressurized and pressure-maintaining, the electromagnetic ball valve YA29 is powered on, and the cartridge valve C29 is opened.

When the sliding block is fast down, the electromagnetic directional valve YA30 is powered on, the cartridge valve C32 is opened, the electromagnetic directional valve YA30 in other working procedures is powered off, and the cartridge valve C32 is closed.

When the sliding block is quickly lowered and the electromagnetic directional valve YA31 is powered on, the hydraulic control port of the cartridge valve C33 is controlled by the pressure regulating valve F16, namely 3-8MPa; when the slider is kept pressure and the electromagnetic directional valve YA31 is powered off, the hydraulic control port of the cartridge valve C33 is controlled by the pressure regulating valve F17, namely 25MPa.

When the mold is repeatedly opened, oil is supplemented to the return cylinder through the cartridge valve C30.

The die opening control valve group comprises first to fourth die opening control valve groups, the first die opening control valve group comprises a cartridge valve C34 and a cartridge valve C35, an inlet of the cartridge valve C35 is connected with the main pressure oil way PB2, an outlet of the cartridge valve C35 is connected with a lower cavity oil port of the leveling die opening cylinder I and an inlet of the cartridge valve C34, and an outlet of the cartridge valve C34 is connected with the oil tank.

The hydraulic control port of the cartridge valve C34 is connected with the inlet of the pressure regulating valve F18, the control port of the pressure regulating valve F18 is connected with the oil tank through the remote pressure regulating valve F19, the outlet of the pressure regulating valve F18 is connected with the port B of the electromagnetic directional valve YA32, the hydraulic control port of the cartridge valve C35 is connected with the port A of the electromagnetic directional valve YA32, the port P of the cartridge electromagnetic directional valve YA32 is connected with the outlet of the cartridge valve C35, the port T of the electromagnetic directional valve YA32 is connected with the oil tank, and the electromagnetic directional valve YA32 is a two-position four-way electromagnetic directional valve. And the hydraulic circuits from the second valve group to the fourth valve group are opened, and so on.

When the die is opened, the electromagnetic directional valve YA32 is powered on, the cartridge valve C35 is opened, and pressure oil enters the leveling die opening cylinder I through the cartridge valve C35; the electromagnetic reversing valve YA33 is powered on, the cartridge valve C37 is opened, and pressure oil enters the leveling die opening cylinder II through the cartridge valve C37; the electromagnetic reversing valve YA34 is powered on, the cartridge valve C39 is opened, and pressure oil enters the leveling die opening cylinder III through the cartridge valve C39; the electromagnetic reversing valve YA35 is powered on, the cartridge valve C41 is opened, and pressure oil enters the leveling die opening cylinder IV through the cartridge valve C41.

The heating lower die is provided with a process cylinder 9 for processing a process hole of a pressed product, a main pressure oil way PB2 is connected with a P port of a three-position four-way electromagnetic reversing valve through a pressure regulating valve F26, a T port of the three-position four-way electromagnetic reversing valve is connected with an oil tank, an A port of the three-position four-way electromagnetic reversing valve is connected with a lower cavity oil port of the process cylinder 9, a B port of the three-position four-way electromagnetic reversing valve is connected with an upper cavity oil port of the process cylinder 9, and the middle position function of the three-position four-way electromagnetic reversing valve is Y-shaped.

Before the composite material is formed, the left coil YA37 of the three-position four-way electromagnetic reversing valve is electrified, and the piston rod of the process cylinder 9 is ejected upwards; after the composite material is formed, the right coil YA38 of the three-position four-way electromagnetic directional valve is electrified, the piston rod of the process cylinder 9 is retracted, core pulling is realized, and a process hole is reserved on the composite material product.

The outlet of the main pressure oil path PA1 is connected with the outlet of the main pressure oil path PA2, so as to ensure enough oil supply quantity of sixteen main cylinders. The outlet of the main pressure oil path PB1 is connected with the outlet of the main pressure oil path PB2, so that the sufficient oil supply quantity of the two return cylinders and the four leveling die sinking cylinders is ensured. The main pressure oil passage is installed with a pressure sensor BP1 to monitor the pressure of the main pressure oil passage.

The invention relates to a method for pressing a composite material civil air defense airtight door by a hydraulic press, which comprises the following specific working steps:

step 1: and raising the temperature of the upper heating die and the lower heating die to 150-180 ℃.

Step 2: and removing the anti-oxidation protective films on two sides of the composite material molded sheet, cutting the composite material molded sheet, and weighing to confirm that the composite material molded sheet meets the design weight.

The composite material molding sheet can adopt an SMC molding sheet, and is a molding compound for manufacturing unsaturated polyester glass fiber reinforced plastic products by a dry method. Composition of SMC molded sheet: the middle core material is chopped fiber fully impregnated by resin paste, and the upper surface and the lower surface are covered with anti-oxidation protective films; the resin paste contains unsaturated polyester resin, low shrinkage/low profile additive, initiator, release agent, mineral filler, etc.

Step 3: the composite molded sheet is placed in a mold cavity of a heated lower mold.

Step 4: motor start of each servo pump

The motor M1 is started, the servo pump P1 and the servo pump P2 are driven to work, the motor M2 is started, the servo pump P3 and the servo pump P4 are driven to work, the motor M3 is started, the servo pump P5 and the servo pump P6 are driven to work, the motor M4 is started, the servo pump P7 and the servo pump P8 are driven to work, the motor M5 is started, the servo pump P9 and the servo pump P10 are driven to work, the motor M6 is started, the servo pump P11 and the servo pump P12 are driven to work, the motor M7 is started, and the servo pump P13 and the servo pump P14 are driven to work; the servo pumps P1, P3, P5, P7, P9, P11 and P13 are low-pressure large-flow pumps, and the servo pumps P2, P4, P6, P8, P10, P12 and P14 are high-pressure small-flow pumps; the rotation speed of each servo pump is 100-200rpm.

Step 5: slide block fast descending

The electromagnetic reversing valve YA1 is powered on, the cartridge valve C2 is closed, the cartridge valve C1 is opened, and the servo pump P1 supplies oil to the main pressure oil path PA1 and the main pressure oil path PB 1;

the electromagnetic reversing valve YA2 is powered on, the cartridge valve C4 is closed, the cartridge valve C3 is opened, and the servo pump P2 supplies oil to the main pressure oil path PA1 and the main pressure oil path PB 1;

The electromagnetic reversing valve YA3 is powered on, the cartridge valve C6 is closed, the cartridge valve C5 is opened, and the servo pump P3 supplies oil to the main pressure oil path PA1 and the main pressure oil path PB 1;

the electromagnetic reversing valve YA4 is powered on, the cartridge valve C8 is closed, the cartridge valve C7 is opened, and the servo pump P4 supplies oil to the main pressure oil path PA1 and the main pressure oil path PB 1;

the electromagnetic reversing valve YA5 is powered on, the cartridge valve C10 is closed, the cartridge valve C9 is opened, and the servo pump P5 supplies oil to the main pressure oil path PA1 and the main pressure oil path PB 1;

the electromagnetic reversing valve YA6 is powered on, the cartridge valve C12 is closed, the cartridge valve C11 is opened, and the servo pump P6 supplies oil to the main pressure oil path PA1 and the main pressure oil path PB 1;

the electromagnetic reversing valve YA7 is powered on, the cartridge valve C14 is closed, the cartridge valve C13 is opened, and the servo pump P7 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2;

the electromagnetic reversing valve YA8 is powered on, the cartridge valve C16 is closed, the cartridge valve C15 is opened, and the servo pump P8 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2;

the electromagnetic reversing valve YA9 is powered on, the cartridge valve C18 is closed, the cartridge valve C17 is opened, and the servo pump P9 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2;

the electromagnetic reversing valve YA10 is powered on, the cartridge valve C20 is closed, the cartridge valve C19 is opened, and the servo pump P10 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2;

The electromagnetic reversing valve YA11 is powered on, the cartridge valve C22 is closed, the cartridge valve C21 is opened, and the servo pump P11 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2;

the electromagnetic reversing valve YA12 is powered on, the cartridge valve C24 is closed, the cartridge valve C23 is opened, and the servo pump P12 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2;

the electromagnetic reversing valve YA13 is powered on, the cartridge valve C26 is closed, the cartridge valve C25 is opened, and the servo pump P13 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2;

the electromagnetic directional valve YA14 is powered on, the cartridge valve C28 is closed, the cartridge valve C27 is opened, and the servo pump P14 supplies oil to the main pressure oil path PA2 and the main pressure oil path PB 2; the rotational speed of each servo pump was increased to 1000rpm.

The electromagnetic reversing valve YA27 is in a power-off state, the hydraulic control port of the cartridge valve C52 is closed by pressure building, and the main pressure oil paths PA1, PA2, PB1 and PB2 are subjected to pressure building;

the electromagnetic reversing valve YA26 is electrified, the port A is communicated with the port T, so that the cartridge valve C51 is opened, the pressure oil in the main pressure oil way PA1 or PA2 pushes the cartridge valve C50 to enter the main oil way PC1, and the oil pressure of the main oil way PC1 is sent to the control system by the pressure sensor BP 2.

The electromagnetic reversing valve YA15 is powered on, the cartridge valve C42 is opened, and the pressure oil in the main oil cylinder oil way PC1 enters the upper cavity of the first group of four main oil cylinders;

The electromagnetic reversing valve YA17 is powered on, the cartridge valve C43 is opened, and the pressure oil in the main oil cylinder oil way PC1 enters the upper cavity of the second group of four main oil cylinders;

the electromagnetic reversing valve YA19 is powered on, the cartridge valve C44 is opened, and the pressure oil in the main oil cylinder oil way PC1 enters the upper cavity of the third group of four main oil cylinders;

the electromagnetic reversing valve YA21 is powered on, the cartridge valve C45 is opened, and the pressure oil in the main oil cylinder oil way PC1 enters the upper cavity of the fourth group of four main oil cylinders;

the electro-hydraulic reversing valve YA23 is powered on, and the pressure of a control oil way AK under the liquid filling valve is relieved;

the electromagnetic ball valve YA24 is powered on, the cartridge valve C54 is opened, pressure oil in the accumulator AC1 enters the control oil way BK on the liquid filling valve through the cartridge valve C54, and all the liquid filling valves are actively opened; the oil in the upper oil tank is quickly fed into the upper cavity of each main oil cylinder.

The electromagnetic directional valve YA25 is in a power-off state, and the cartridge valve C53 is closed.

The electromagnetic reversing valve YA28 is in a power-off state, and the cartridge valve C31 is closed; the electromagnetic ball valve YA29 is powered on, and the cartridge valve C29 is opened; the electromagnetic reversing valve YA30 is powered on, the cartridge valve C32 is opened, and the return cylinder returns oil to the oil tank in the process of quickly descending the sliding block.

The sliding block rapidly descends under the action of dead weight, so that the heating upper die is rapidly close to the top of the composite material molding sheet;

the electromagnetic reversing valve YA31 is electrified, the port A is communicated with the port T, the hydraulic control port of the cartridge valve C33 is controlled by the pressure regulating valve F16, the set pressure of the pressure regulating valve F16 is 3-8MPa, and the impact of the sliding block during slow descending is relieved.

Step 6: sliding block slowly descends

After the sliding block reaches a speed change point, the electro-hydraulic reversing valve YA23 is powered off, the upper control oil way BK of the liquid filling valve is depressurized, the lower control oil way AK of the liquid filling valve is pressurized, the lower hydraulic control port of each liquid filling valve is pressurized, and each liquid filling valve is actively closed; the upper cavity of each main oil cylinder only receives oil from the main oil cylinder oil way PC1, so that the speed is reduced;

the electromagnetic reversing valve YA30 is powered off, the cartridge valve C32 is closed, the pressure of each return cylinder is controlled to be 3-8Mpa by the set pressure of the pressure regulating valve F16, supporting force is provided for the sliding block, and the sliding block slowly moves downwards to heat and upper die press the upper surface of the composite material die pressing sheet; the rotational speed of each servo pump was increased to 2000rpm.

In the slow down process, the die opening lugs at the four corners of the sliding block are respectively abutted against the upper ends of the plungers of the corresponding leveling die opening cylinders, and the sliding block is leveled in the forced withdrawal process of the plungers of the leveling die opening cylinders so as to avoid inclination. Displacement sensors are respectively arranged at the four corners of the sliding block to monitor the displacement amounts of the four corners of the sliding block.

The hydraulic control port of the cartridge valve C34 is controlled by a pressure regulating valve F18, the set pressure of the pressure regulating valve F18 is controlled by a remote pressure regulating valve F19, and the set value of the remote pressure regulating valve F19 can be adjusted between 0 and 25MPa so as to change the pressure of the leveling die opening cylinder I;

The hydraulic control port of the cartridge valve C36 is controlled by a pressure regulating valve F20, the set pressure of the pressure regulating valve F20 is controlled by a remote pressure regulating valve F21, and the set value of the remote pressure regulating valve F21 can be adjusted between 0 and 25MPa so as to change the pressure of the leveling die opening cylinder II;

the hydraulic control port of the cartridge valve C38 is controlled by a pressure regulating valve F22, the set pressure of the pressure regulating valve F22 is controlled by a remote pressure regulating valve F23, and the set value of the remote pressure regulating valve F23 can be adjusted between 0 and 25MPa so as to change the pressure of the leveling die opening cylinder III;

the hydraulic control port of the cartridge valve C40 is controlled by a pressure regulating valve F24, the set pressure of the pressure regulating valve F24 is controlled by a remote pressure regulating valve F25, and the set value of the remote pressure regulating valve F25 can be adjusted between 0 and 25MPa so as to change the pressure of the leveling die opening cylinder four;

the pressure of each leveling die opening cylinder is adjusted, so that the sliding blocks can be leveled respectively, and unbalanced load is prevented in the descending process.

Step 7: slider pressurization

The electromagnetic ball valve YA24 is kept powered, the cartridge valve C54 is kept open, the oil of the accumulator AC1 is continuously supplied to the charging valve, and the charging valve is ensured to be closed; the rotational speed of each servo pump was maintained at 2000rpm;

the main oil cylinder oil way PC1 pressurizes the upper cavities of the first group of four main oil cylinders through a cartridge valve C42, the main oil cylinder oil way PC1 pressurizes the upper cavities of the second group of four main oil cylinders through a cartridge valve C43, the main oil cylinder oil way PC1 pressurizes the upper cavities of the third group of four main oil cylinders through a cartridge valve C44, and the main oil cylinder oil way PC1 pressurizes the upper cavities of the fourth group of four main oil cylinders through a cartridge valve C45;

Under the heating state, sixteen main oil cylinders drive the heating upper die to gradually and downwards clamp, the total pressing force is more than ten thousand tons, and the composite material die pressing sheet material flows in the die cavity and gradually fills the die cavity;

step 8: slider pressure maintaining

When the pressure of the upper cavity of the sliding block is pressurized to 25MPa, the pressure sensor BP2 sends a signal, and the pressure is maintained; since the set pressure of the pressure regulating valve F1 is only 10MPa and the set pressure of the pressure regulating valve F2 is 25MPa, the pressure sensor installed at the pump port of the servo pump P2 transmits a signal when maintaining pressure, and the servo pump P1 with low pressure and large flow is stopped by the servo driver, and only the servo pump P2 with high pressure and small flow is used;

the electromagnetic reversing valve YA1 is powered off, the cartridge valve C2 is opened, and the outlet of the servo pump P1 is communicated with the lower oil tank through the cartridge valve C2; the cartridge valve C1 is closed;

the electromagnetic directional valve YA2 is kept powered, and the servo pump P2 is kept supplying oil to the main pressure oil path PA1 and the main pressure oil path PB1, and the rotating speed is 600rpm;

the electromagnetic reversing valve YA31 is powered off, the P port is communicated with the A port, the hydraulic control port of the cartridge valve C33 is controlled by the pressure regulating valve F17, and the set pressure of the pressure regulating valve F17 is 25MPa;

the electromagnetic directional valves YA3 to YA14 are closed, and the outlets of the servo pumps P3 to P14 are communicated with the lower oil tank;

The electromagnetic directional valves YA15, YA17, YA19, and YA21 are kept energized, and the master cylinder oil passage PC1 keeps the upper chamber pressure of each master cylinder.

Step 9: slider pressure relief

The pressure maintaining is delayed until the electromagnetic reversing valve YA2 is powered off, and the outlet of the high-pressure small-flow servo pump P2 is communicated with the lower oil tank through the cartridge valve C4; the other servo pumps are also closed;

the electromagnetic directional valves YA15, YA17, YA19 and YA21 are powered off, and the cartridge valves C42, C43, C44 and C45 are closed; the electromagnetic ball valve YA24 is powered off, and the cartridge valve C54 is closed;

the proportional overflow valves YAA, YAB, YAC, YAD are powered on, so that the port B and the port A are respectively communicated, the upper cavity of each main oil cylinder is controlled by the proportional overflow valves to control the flow, the pressure is slowly relieved to the lower oil tank, the internal stress generated after the composite material is pressed in large tonnage is absorbed, and the rebound vibration of the sliding block caused by too fast pressure relief is avoided; the accumulator AC2 keeps constant pressure of each control oil port of each proportional overflow valve.

Step 10: mold opening

After the pressure relief of the upper cavity of the sliding block is finished, the pressure sensor BP2 sends a signal, and each servo motor is started at 600rpm;

the electromagnetic directional valve YA2 is powered on, and the high-pressure small-flow servo pump P2 supplies oil to the main pressure oil circuit PA1 and the main pressure oil circuit PB 1;

the electromagnetic directional valve YA4 is powered on, and the high-pressure small-flow servo pump P4 supplies oil to the main pressure oil circuit PA1 and the main pressure oil circuit PB 1;

The electromagnetic directional valve YA6 is powered on, and the high-pressure small-flow servo pump P6 supplies oil to the main pressure oil circuit PA1 and the main pressure oil circuit PB 1;

the electromagnetic directional valve YA8 is powered on, and the high-pressure small-flow servo pump P8 supplies oil to the main pressure oil circuit PA2 and the main pressure oil circuit PB 2;

the electromagnetic ball valve YA24 is powered on, the cartridge valve C54 is opened, pressure oil in the accumulator AC1 enters the control oil way BK on the liquid filling valve through the cartridge valve C54, and all the liquid filling valves are actively opened;

the electromagnetic reversing valve YA32 is powered on, the cartridge valve C35 is opened, pressure oil enters the leveling die opening cylinder I through the cartridge valve C35, a hydraulic control port of the cartridge valve C34 is controlled by the pressure regulating valve F18, the set pressure of the pressure regulating valve F18 is controlled by the remote pressure regulating valve F19, and the set value of the remote pressure regulating valve F19 can be adjusted between 0 MPa and 25MPa so as to change the lower cavity pressure of the leveling die opening cylinder I;

the electromagnetic reversing valves YA33, YA34 and YA35 are powered on in the same way, pressure oil enters the other leveling die-sinking cylinders simultaneously, piston rods of the leveling die-sinking cylinders extend out by 10mm, and the sliding blocks are pushed to stably ascend by 10mm through die-sinking lugs. The pressure of each leveling die opening cylinder is adjusted by adjusting the set pressure of the remote pressure regulating valves F19, F21, F23 and F25, so as to level the upper die;

After the heating upper die is opened, hot air is discharged; simultaneously, air enters into contact with the product to promote the solidification of the product;

in the die sinking process, the plunger of the return cylinder moves upwards, and oil in the lower oil tank is supplied to the lower cavity of the return cylinder through the cartridge valve C30.

And then repeatedly executing the steps 6 to 10 according to the times set by the process, namely slowly descending the sliding block, pressurizing, maintaining pressure, releasing pressure and opening the die until the last opening of the die is completed, so that the density, thickness, flatness and the like of the product meet the requirements.

Step 11: quick return stroke of sliding block

The electromagnetic directional valves YA1 to YA14 are powered, and the servo pumps P1 to P14 supply oil to the main pressure oil paths;

the electro-hydraulic reversing valves YA23 and YA24 are kept powered, and the pressure oil in the accumulator AC1 actively opens all the charging valves;

the electromagnetic reversing valve YA28 is powered on, and the cartridge valve C31 is opened;

the electromagnetic ball valve YA29 is powered on, the cartridge valve C29 is opened, pressure oil enters the lower cavity of each return cylinder, the sliding block is pushed to rapidly ascend, the upper cavity of each main oil cylinder returns oil to the oil tank, and the rotating speed of each servo pump is 1500rpm.

Step 12: sliding block slow return stroke

Before the slide block approaches the top dead center, the rotating speed of each servo pump is reduced to 500rpm;

the electromagnetic ball valve YA29 is powered off, the cartridge valve C29 is pushed away by pressure oil, the pressure oil enters the lower cavity of each return cylinder, and the sliding block is pushed to slowly ascend to the top dead center.

For products requiring processing of process holes such as air-defense airtight doors, the step ST1 is executed when the pressure is maintained for the first time,

step ST1: art cylinder ejection

The electromagnetic directional valve YA2 is kept powered, and the high-pressure small-flow servo pump P2 is kept supplying oil to the main pressure oil path PA1 and the main pressure oil path PB 1;

the left coil YA37 of the three-position four-way electromagnetic reversing valve is powered on, the P port is communicated with the A port, the B port is communicated with the T port, high-pressure oil in the main pressure oil way PB2 enters the lower cavity of the process cylinder, the upper cavity of the process cylinder returns oil from the lower oil tank, the piston rod of the process cylinder is ejected upwards, and process holes, such as mounting holes of a door handle and a door hinge, are extruded on the composite material pressed product. The material density around the process hole is larger, which is beneficial to improving the strength of the process hole part.

At the end of the last dwell time, steps ST2 and ST3 are performed,

step ST2: withdrawal of the craft cylinder

The right coil YA38 of the three-position four-way electromagnetic reversing valve is electrified, the port P is communicated with the port B, the port A is communicated with the port T, high-pressure oil in the main pressure oil way PB2 enters the upper cavity of the process cylinder, the lower cavity of the process cylinder returns oil to the oil tank downwards, the piston rod of the process cylinder is retracted, and a process hole is reserved on the composite material product.

Step ST3: pressure relief of process cylinder

The right coil YA38 of the rear three-position four-way electromagnetic reversing valve is powered off, the P port is closed, the A port and the B port are communicated with the T port, and the upper cavity and the lower cavity of the process cylinder are relieved.

Multiple sets of process cylinders can be arranged according to product needs so as to leave multiple sets of process holes on the product.

When the pressure of the accumulator AC1 is lower than a set value, the pressure sensor BP3 sends a signal, the electromagnetic reversing valve YA25 is powered on, the cartridge valve C53 is opened, and the pressure oil is filled into the accumulator AC1, so that the working procedures of feeding, high pressure and the like can be utilized.

The servo pump P15 can be kept in an operation state all the time, when the pressure of a control oil way of the proportional relief valve YAA, YAB, YAC, YAD is lower than a set value, the pressure sensor BP4 sends a signal, the electromagnetic reversing valve YA36 is powered, the cartridge valve C54 is closed, and pressure oil is filled into the accumulator AC 2.

The foregoing description is only of a preferred embodiment of the invention and is not intended to limit the scope of the invention. In addition to the embodiments described above, other embodiments of the invention are possible. All technical schemes formed by equivalent substitution or equivalent transformation fall within the protection scope of the invention. The technical features of the present invention that are not described may be implemented by or using the prior art, and are not described herein.

Claims

1. The utility model provides a combined material goods thermoforming servo hydraulic press, includes the fuselage, the fuselage includes workstation and entablature that are parallel to each other, be equipped with stand, its characterized in that between four bights of workstation and entablature respectively: the upper beam is provided with a plurality of main cylinders which are uniformly distributed in a rectangular array, the lower ends of plungers of the main cylinders are respectively and fixedly connected with the sliders, the middle parts of the left side and the right side of the sliders are respectively and fixedly provided with slider lugs, the slider lugs are respectively connected with the upper ends of plungers of return cylinders, and the cylinder bodies of the return cylinders are respectively fixed on the workbench and positioned in the middle parts between the front upright post and the rear upright post;

leveling die opening cylinders are symmetrically arranged on the front side and the rear side of the two return cylinders respectively, the cylinder bodies of the leveling die opening cylinders are fixed on the workbench, and the plunger tops of the leveling die opening cylinders are positioned below the die opening support lugs of the sliding blocks;

the upper cavity oil ports of the main oil cylinders are respectively connected with an upper oil tank through liquid filling valves, the lower liquid control ports of the liquid filling valves are respectively connected with a liquid filling valve lower control oil path AK, the upper liquid control ports of the liquid filling valves are respectively connected with a liquid filling valve upper control oil path BK, and the upper cavity oil ports of the main oil cylinders are also respectively connected with a main oil cylinder oil path PC1 through main oil cylinder control valve groups; the oil ports of the lower cavities of the two return cylinders are connected with a main pressure oil circuit through a return control valve group; the lower cavity oil ports of the leveling die opening cylinders are respectively connected with a main pressure oil circuit through a die opening control valve group;

The inlet of the cartridge valve C53 is connected with a main pressure oil way, the outlet of the cartridge valve C53 is connected with the accumulator AC1 and the inlet of the cartridge valve C54 through a one-way valve D1, the outlet of the cartridge valve C54 is connected with the P port of the electro-hydraulic reversing valve YA23, the T port of the electro-hydraulic reversing valve YA23 is connected with an oil tank, the A port of the electro-hydraulic reversing valve YA23 is connected with the lower control oil way AK of the liquid filling valve, and the B port of the electro-hydraulic reversing valve YA23 is connected with the upper control oil way BK of the liquid filling valve;

2. The composite article thermoforming servo hydraulic press as claimed in claim 1, wherein: sixteen main cylinders are arranged in the upper cross beam and are uniformly arranged in four rows and four columns.

3. The composite article thermoforming servo hydraulic press as claimed in claim 1, wherein: the inlets of the cartridge valve C51 and the cartridge valve C52 are respectively connected with a main pressure oil circuit, the outlet of the cartridge valve C51 is connected with the inlet of the cartridge valve C50, and the outlet of the cartridge valve C50 is connected with the main oil cylinder oil circuit PC 1; the outlet of the cartridge valve C52 is connected with a lower oil tank of the hydraulic system;

4. The composite article thermoforming servo hydraulic press as claimed in claim 1, wherein: the upper cavity oil ports of the four adjacent main cylinders are controlled by the same group of main cylinder control valve groups, the first main cylinder control valve group comprises a cartridge valve C42 and a proportional overflow valve YAA, the inlet of the cartridge valve C42 is connected with the main cylinder oil path PC1, the outlet of the cartridge valve C42 is connected with the upper cavity oil ports of all the main cylinders of the group and the B port of the proportional overflow valve YAA, and the A port of the proportional overflow valve YAA is connected with an oil tank;

5. The composite article thermoforming servo hydraulic press as claimed in claim 1, wherein: the return control valve group comprises cartridge valves C29 to C33, the inlet of the cartridge valve C31 is connected with a main pressure oil way, the outlet of the cartridge valve C31 is connected with the inlets of the cartridge valve C29, the cartridge valve C32 and the cartridge valve C33, the outlet of the cartridge valve C29 is connected with the outlet of the cartridge valve C30 and the lower cavity oil ports of the return cylinders, the inlet of the cartridge valve C30 is connected with a lower oil tank, and the outlets of the cartridge valve C32 and the cartridge valve C33 are connected with a lower oil tank;

6. The composite article thermoforming servo hydraulic press as claimed in claim 1, wherein: the die opening control valve group comprises first to fourth die opening control valve groups, the first die opening control valve group comprises a cartridge valve C34 and a cartridge valve C35, an inlet of the cartridge valve C35 is connected with a main pressure oil circuit, an outlet of the cartridge valve C35 is connected with a lower cavity oil port of the leveling die opening cylinder I and an inlet of the cartridge valve C34, and an outlet of the cartridge valve C34 is connected with an oil tank;

7. The composite article thermoforming servo hydraulic press as claimed in claim 1, wherein: the heating lower die is provided with a process cylinder in a processing process hole of a pressed product, a main pressure oil way is connected with a P port of a three-position four-way electromagnetic reversing valve through a pressure regulating valve F26, a T port of the three-position four-way electromagnetic reversing valve is connected with an oil tank, an A port of the three-position four-way electromagnetic reversing valve is connected with a lower cavity oil port of the process cylinder, a B port of the three-position four-way electromagnetic reversing valve is connected with an upper cavity oil port of the process cylinder, and the middle position function of the three-position four-way electromagnetic reversing valve is Y-shaped.

8. A method for pressing a composite material civil air defense airtight door by a hydraulic press, which is characterized by adopting the composite material product thermoforming servo hydraulic press as claimed in claim 1, and sequentially comprising the following steps: