CN110873085B

CN110873085B - Synchronous control method for hydraulic oil cylinder of cubic press

Info

Publication number: CN110873085B
Application number: CN201911211860.9A
Authority: CN
Inventors: 闫宁; 陈亦工; 王孝琪; 赵延军; 潘薇; 古龙辉
Original assignee: Zhengzhou Research Institute for Abrasives and Grinding Co Ltd
Current assignee: Jinggong Ruiyi Technology Henan Co ltd; Zhengzhou Research Institute for Abrasives and Grinding Co Ltd
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2021-07-27
Anticipated expiration: 2039-12-02
Also published as: CN110873085A

Abstract

The invention discloses a synchronous control method for hydraulic cylinders of a cubic press, which comprises the steps of returning a working cylinder, placing a synthetic block, idling and pausing, then enabling a reciprocating supercharger to enter a constant volume conversion mode for synchronous liquid charging, then enabling the reciprocating supercharger to enter a constant volume and supercharging ratio overpressure mode for synchronous overpressure, and finally performing pressure maintaining and pressure relief; the invention can ensure the synchronous displacement control precision of the six-cylinder equal-volume oil supply, so that the synchronous control precision reaches 0.1 mm-0.2 mm, the reciprocating supercharger can also be used as an ultrahigh pressure oil source to load the working oil cylinder to the working pressure of 120MPa, and the invention can also realize the accurate control of the six-cylinder synchronous displacement in the processes of liquid filling and overpressure.

Description

Synchronous control method for hydraulic oil cylinder of cubic press

Technical Field

The invention relates to the technical field of hydraulic control, in particular to a synchronous control method for a hydraulic oil cylinder of a cubic press.

Background

The cubic apparatus press is the main equipment for synthesizing artificial diamond in China, and the working principle is as follows: the six working oil cylinders are opposite to each other in pairs on the three coordinate axes of XZY, high-pressure oil is introduced from six directions to pressurize the center of the main machine and push the piston to advance, so that the front end face of the piston generates ultrahigh pressure, the production raw material block forms a sealed square ultrahigh-pressure cavity under the action of a hard alloy anvil at the center of the main machine, and the cavity provides a high-pressure condition for synthesizing artificial diamond. The position precision of the press piston moving to three coordinate centers in the pressurizing process has decisive influence on the production performance, so that whether the pressurizing cylinder in the hydraulic system has higher synchronous precision or not has great significance for reducing the consumption of the expensive hard alloy top hammer and improving the product quality. At present, most of conventional hydraulic systems of cubic presses are shown in fig. 1, an electro-hydraulic control system is adopted to control all components in the hydraulic system, six throttle valves from a throttle valve 23 to a throttle valve 28 are used for adjusting the speed matching of six working cylinders from a working cylinder 3 to a working cylinder 8 and the synchronous precision requirement of the cylinders, and the problems exist that the adjusting processes of the six fixed throttle valves are not unified standard, the six fixed throttle valves are manually adjusted completely by experience, the six fixed throttle valves are influenced by the oil temperature and the compression deformation resistance fluctuation of raw material blocks during working, the repeated precision change of the synchronous displacement of the six working cylinders is large, the displacement speed of the six working cylinders can be adjusted and controlled only in the liquid filling process of the press, and high-pressure oil does not pass through the throttle valves 23 to 28 in an overpressure section of 10-120 MPa, and cannot be adjusted in a synchronous movement mode.

Disclosure of Invention

The invention aims to provide a synchronous control method for hydraulic cylinders of a cubic press, which can respectively supply oil to six working cylinders with equal capacity to push the pistons in the six working cylinders to accurately and synchronously displace, realize accurate synchronous control in both a liquid filling process and an overpressure process, and simultaneously have the advantages of simple structure and high flexibility.

The technical scheme adopted by the invention is as follows:

the utility model provides a cubic press hydraulic cylinder synchronous control method, cubic press hydraulic system include six work hydro-cylinders, are three location jar and three movable cylinder respectively, and the homogeneous one-to-one correspondence is connected with single cylinder oil supply line on every work hydro-cylinder, and the main oil supply line is connected respectively to six way single cylinder oil supply line's oil inlet, and the direction when flowing to work hydro-cylinder by hydraulic oil on the single cylinder oil supply line is equipped with single cylinder switching-over valve and superhigh pressure pilot operated check valve in proper order, includes following step:

A. and (3) returning the working oil cylinder: returning the three positioning cylinders and the three moving cylinder pistons, wherein the positioning cylinder pistons return to a preset position, and the moving cylinder pistons return to the bottom; when the positioning cylinder returns to the right position, the distance from the end surface of the anvil arranged at the front end of the positioning cylinder piston to the center of the coordinate origin of the cubic press is 1/2 of the side length of the hexagonal synthetic block to be processed;

B. placing a synthetic block: placing the hexagonal synthetic block to be processed into the positioning cylinder, and enabling the hexagonal synthetic block to be processed to be tightly attached to the end face of a top hammer arranged at the front end of the positioning cylinder piston;

C. idle-in and pause: the piston of each movable cylinder moves forward to the original point position of the coordinate center of the cubic press until the front end surface of the anvil of the movable cylinder contacts the synthesis block, and the piston moves forward to the right position and stops moving; when all the three moving cylinder pistons advance to the right position, starting to time the pause time;

D. after the pause timing is finished, the working oil cylinder is synchronously filled with liquid through the reciprocating supercharger, and the reciprocating supercharger enters an equal-capacity conversion working mode: the specific process is as follows:

d 1: the reciprocating superchargers are arranged between the main oil supply pipeline and the ultrahigh pressure hydraulic control one-way valve, the reciprocating superchargers correspond to the working oil cylinders one by one, then the electromagnetic directional valve between the main oil supply return pipeline and the single cylinder oil supply pipeline is powered off, the electromagnetic directional valve between the main oil supply pipeline and the reciprocating superchargers is powered on and sucked, and all pressure oil of the main oil pump enters P ports of six identical electromagnetic valves of the reciprocating superchargers;

d 2: cutting off oil supply pipelines of the six working oil cylinders from the main oil pump to separate the oil supply pipelines of the six working oil cylinders from each other;

d 3: the oil discharge ports of the high-pressure plungers of the six reciprocating superchargers are connected to the outlet of the ultrahigh-pressure one-way valve in parallel, the T ports of the electromagnetic valves of the six reciprocating superchargers are connected to the inlet of the ultrahigh-pressure hydraulic control one-way valve in parallel, and the oil discharged by the low-pressure pistons of the reciprocating superchargers flows out of the T ports of the electromagnetic valves of the reciprocating superchargers and is merged into the inlet of the ultrahigh-pressure hydraulic control one-way valve;

d 4: high-pressure and low-pressure oil output of the reciprocating supercharger is simultaneously and quantitatively injected into the working oil cylinders, so that the six working oil cylinder pistons rapidly and synchronously move until the charging pressure of the working oil cylinders reaches a preset hydraulic threshold;

d 5: when the liquid filling pressure of the six working oil cylinders reaches a preset hydraulic threshold, the liquid filling action is finished, and the six working oil cylinders are switched to overpressure operation;

E. the six cylinders synchronously generate overpressure, and the reciprocating supercharger enters an overpressure working mode with constant volume and pressure ratio: when the charging pressure of the working oil cylinder reaches a preset hydraulic threshold, the supercharger starts oil pumping, high-pressure oil is injected into the six cylinders through the six-way flow divider valve, and the piston anvil is pushed to further extrude a synthesized block until the pressure of the working oil cylinder reaches the preset ultrahigh pressure threshold; the specific process is as follows:

e 1: pressure oil of a main oil pump enters P ports of six reciprocating supercharger electromagnetic valves;

e 2: cutting off oil supply pipelines of the six working oil cylinders from the main oil pump to isolate the oil supply pipelines of the six working oil cylinders from each other;

e 3: the oil discharge ports of the high-pressure plungers of the six reciprocating superchargers are connected in parallel and then connected to the outlet of the ultrahigh-pressure one-way valve, the T ports of the electromagnetic valves of the six reciprocating superchargers are connected in parallel to the inlet of the ultrahigh-pressure hydraulic control one-way valve, at the moment, the six single-cylinder reversing valves in the single-cylinder oil supply pipeline are all electrified and sucked, and the oil discharged by the low-pressure pistons of the reciprocating superchargers flows out of the T ports of the electromagnetic valves of the reciprocating superchargers and returns to an oil tank;

e 4: the high-pressure oil output pressurized by the reciprocating supercharger is quantitatively injected into the working oil cylinders, so that the pistons of the six working oil cylinders synchronously move;

e 5: the interval on-off reversing of the electromagnetic valve of the reciprocating booster is controlled by an electro-hydraulic control system, so that the piston of the reciprocating booster swings left and right, and the oil pressurized in a reciprocating manner continuously flows into the corresponding working oil cylinder until the pressure of the oil cylinder is increased to a preset ultrahigh pressure threshold value and then stops;

F. pressure maintaining and pressure relief: maintaining ultrahigh pressure synthesis pressure, simultaneously introducing large current into the synthesis block for heating, synthesizing diamond at high temperature and high pressure, then stopping heating after the high temperature and high pressure synthesis is finished, opening the ultrahigh pressure servo relief valve, and releasing the pressure of the six working oil cylinders.

Further, the specific process of the step d3 is as follows:

d 3.1: the pressure oil enters a left oil port of the reciprocating supercharger and pushes a piston of the reciprocating supercharger to move right, the piston of the reciprocating supercharger moving right flows out the oil pressure of a right cavity of the piston of the reciprocating supercharger and flows to an oil supply pipeline of the corresponding working oil cylinder, and then the oil flows upwards to enter the corresponding working oil cylinder through the ultrahigh pressure hydraulic control one-way valve;

d 3.2: the pressure oil flowing in by the ultrahigh pressure hydraulic control one-way valve pushes the corresponding working oil cylinder piston to move forwards synchronously, and simultaneously, the pressure oil discharged by the high-pressure plunger at the right end of the reciprocating supercharger flows into the corresponding working oil cylinder through the oil pipe and is combined with the oil discharged by the piston of the reciprocating supercharger to push the piston to move forwards together, namely the pressure oil discharged by the high-pressure plunger at the right end of the reciprocating supercharger flows into the corresponding working oil cylinder through the oil pipe and is combined with the pressure oil flowing in by the ultrahigh pressure hydraulic control one-way valve to push the working oil cylinder piston to move forwards together;

d 3.3: when the piston of the reciprocating supercharger moves right in place, the electromagnetic valve of the reciprocating supercharger reverses, and pressure oil in the reciprocating supercharger enters the oil port at the right end of the reciprocating supercharger and pushes the piston of the reciprocating supercharger to move left;

d 3.4: the left-going piston flows out and flows oil in a left cavity of the piston of the reciprocating supercharger to an oil supply pipeline of the corresponding working oil cylinder, and then the oil goes upward to enter the corresponding working oil cylinder through the ultrahigh-pressure hydraulic control one-way valve;

d 3.5: the pressure oil flowing into the ultrahigh pressure hydraulic control one-way valve pushes the corresponding working oil cylinder piston to synchronously advance, and meanwhile, the oil pressed out by the left high pressure plunger of the reciprocating supercharger enters the corresponding working oil cylinder through the corresponding oil cylinder and is converged with the pressure oil flowing into the ultrahigh pressure hydraulic control one-way valve to synchronously advance together with the piston of the working oil cylinder until the charging pressure of the working oil cylinder reaches a preset hydraulic threshold;

furthermore, in the step d3.3, the reciprocating supercharger moves right to the right position, a travel switch arranged on the end head of the reciprocating supercharger sends a signal to the electro-hydraulic control system, the electro-hydraulic control system controls the piston to stop, or the electro-hydraulic control system sets the time according to the preset time

Further, the specific process of step e3 is as follows:

e 3.1: the pressure oil enters a left oil port of the reciprocating supercharger and pushes a piston of the reciprocating supercharger to move right;

e 3.2: under the pushing of the right-going piston, oil in the right cavity of the piston of the reciprocating supercharger is extruded out and flows to an oil supply pipeline of the corresponding working oil cylinder;

e 3.3: the oil pressed out from the right cavity of the piston of the reciprocating supercharger enters an oil tank through an oil supply pipeline corresponding to the working oil cylinder;

e 3.4: pressurized oil discharged by a high-pressure plunger at the right end of the reciprocating supercharger flows into a corresponding working oil cylinder through an oil pipe to push a piston to move forwards, the advancing piston compresses the hexagonal composite block to be processed, and the oil pressure in the working oil cylinder rises along with the increase of compression load;

e 3.5: when the piston of the reciprocating supercharger moves right in place, the electromagnetic valve of the reciprocating supercharger reverses, and pressure oil in the reciprocating supercharger enters the oil port at the right end of the reciprocating supercharger and pushes the piston of the reciprocating supercharger to move left;

e 3.6: under the pushing of the left-going piston, oil in a left cavity of the piston of the reciprocating supercharger is extruded out and enters an oil supply pipeline of the corresponding working oil cylinder;

e 3.7: the oil pressed out from the left cavity of the reciprocating supercharger enters an oil tank through an oil supply pipeline corresponding to the working oil cylinder;

e 10: high-pressure oil pressurized and extruded by a high-pressure plunger at the left end of the reciprocating booster enters a corresponding working oil cylinder to carry out overpressure so as to push the piston to move forwards synchronously.

Furthermore, in the step e3.5, the reciprocating supercharger moves right to the right position, a travel switch arranged on the end head of the reciprocating supercharger sends a signal to the electro-hydraulic control system, and the electro-hydraulic control system controls the piston to stop, or the electro-hydraulic control system sets the time according to the preset time.

Further, the pause time in the step C is 1 s-10 s.

Further, the method for cutting off the oil supply lines of the six working cylinders from the main oil pump in the steps d2 and e2 is to install a check valve between each cylinder line and the main oil pump, wherein the check valve flows to the working cylinders from the main oil pump.

Furthermore, in the step C, a travel switch or a displacement sensor is arranged on the end face of the movable cylinder top hammer.

Further, the preset hydraulic threshold is 5 MPa-10 MPa.

Further, the preset ultrahigh pressure threshold value is 40-120 MPa

The invention has the following beneficial effects:

(1) the reciprocating superchargers are adopted to carry out liquid filling control on the working oil cylinders in a one-to-one correspondence manner, the fluctuation of the piston motion load and the change of the oil temperature of the six working oil cylinders are utilized by utilizing the high volume efficiency and the incompressibility of hydraulic oil of the reciprocating superchargers, the displacement change of the reciprocating superchargers is not influenced, namely the synchronous motion precision of the six cylinders is not influenced, the synchronous displacement control precision of the six cylinders for equal volume oil supply is ensured, the synchronous control precision can reach 0.1 mm-0.2 mm, and the reciprocating superchargers can also be used as ultrahigh pressure oil sources to load the oil pressure of the working oil cylinders to the working pressure of 120 MPa; meanwhile, the six-cylinder synchronous displacement control device can control the six-cylinder synchronous displacement in the liquid filling process of the cubic press, and can also accurately control the six-cylinder synchronous displacement in the overpressure process;

(2) in the liquid filling stage of the press, oil discharged by a high-pressure plunger of a reciprocating supercharger is connected in parallel to an outlet of an ultrahigh-pressure one-way valve, oil discharged by a low-pressure piston of the reciprocating supercharger flows out of a T port of an electromagnetic valve of the reciprocating supercharger and is connected in parallel to an inlet of the ultrahigh-pressure one-way valve, and high-pressure and low-pressure oil discharged by the reciprocating supercharger is simultaneously injected into a working oil cylinder in a high-precision and quantitative mode, so that the piston of the oil cylinder can move quickly and accurately;

(2) by mutually separating the oil supply pipelines of the six working oil cylinders in the liquid filling process, when the reciprocating supercharger provides pressure oil for the single-cylinder oil supply pipeline, the six single-cylinder oil supply pipelines can be mutually separated, the equivalent oil supply of the six cylinders is ensured, and the precision of the synchronous control of the six cylinders is further ensured.

Drawings

FIG. 1 is an electrical schematic diagram of a prior art cubic press hydraulic system;

FIG. 2 is a flow chart of the present invention;

fig. 3 is an electrical schematic of a pilot operated system used in an embodiment.

Detailed Description

The invention discloses a synchronous control method for hydraulic cylinders of a cubic press.A hydraulic system of the cubic press comprises six working cylinders, namely three positioning cylinders and three movable cylinders, wherein each working cylinder is uniformly and correspondingly connected with a single-cylinder oil supply pipeline, oil inlets of the six single-cylinder oil supply pipelines are respectively connected with a main oil supply pipeline, and a single-cylinder reversing valve and an ultrahigh-pressure hydraulic control one-way valve are sequentially arranged on the single-cylinder oil supply pipeline in the direction from the hydraulic oil flowing to the working cylinders; as shown in fig. 2, the process of the method of the present invention comprises the following steps:

D. after the pause timing is finished, the working oil cylinder is synchronously filled with liquid through the reciprocating supercharger, and the reciprocating supercharger enters an equal-capacity conversion working mode; the specific process is as follows:

E. the six cylinders synchronously generate overpressure, and the reciprocating supercharger enters an overpressure working mode with constant volume and pressure ratio: when the charging pressure of the working oil cylinder reaches a preset hydraulic threshold, high-pressure oil is injected into the six cylinders through the six-way flow divider valve, and the piston top hammer is pushed to further extrude the synthesized block until the pressure of the working oil cylinder reaches a preset ultrahigh pressure threshold; the specific process is as follows:

e 3: the oil discharge ports of the high-pressure plungers of the six reciprocating superchargers are connected in parallel to the outlet of the ultrahigh-pressure one-way valve, the T ports of the electromagnetic valves of the six reciprocating superchargers are connected in parallel to the inlet of the ultrahigh-pressure hydraulic control one-way valve, at the moment, the six single-cylinder reversing valves in the single-cylinder oil supply pipeline are all electrified and sucked, and the oil discharged by the low-pressure pistons of the reciprocating superchargers flows out of the T ports of the electromagnetic valves of the reciprocating superchargers;

when the charging pressure is below 10MPa, the oil supply pressure of the main oil pump can meet the requirement, and the reciprocating booster is not needed for boosting, so that the quantitative oil discharge and the high-pressure oil discharge of the piston of the reciprocating booster can be combined and injected into the working oil cylinder, and the flow and the pressure are both 1:1 conversion; in the overpressure working section, the final pressure needs to reach the ultrahigh pressure of more than 100MPa, so that the reciprocating supercharger needs to rely on the oil discharge overpressure of the high-pressure plunger, the oil of the piston of the reciprocating supercharger needs to return to an oil tank, the conversion of the pressure of 7:1 and the flow of 1:7 is realized, and the supercharging effect is ensured;

The invention adopts the method that the high-pressure plunger oil discharge of the reciprocating booster is connected in parallel to the outlet of the ultrahigh-pressure one-way valve, the low-pressure piston oil discharge of the reciprocating booster flows out of the T port of the electromagnetic valve of the reciprocating booster and is connected in parallel to the inlet of the ultrahigh-pressure one-way valve, and the high-pressure oil discharge and the low-pressure oil discharge of the reciprocating booster are simultaneously injected into the working oil cylinder in a high-precision quantitative manner, so that the piston of the oil cylinder moves quickly and accurately; meanwhile, a method of adding a reciprocating supercharger and a method of mutually separating six oil supply pipelines during liquid filling are adopted to ensure the synchronous control of the six working oil cylinders during liquid filling.

The process flow of the present invention is further explained below with reference to specific examples. It should be noted that the embodiment is only one implementation manner of the present invention, and is a reference example for better explaining the method, and does not limit the structure of the control system used in the present invention.

As shown in fig. 3, the hydraulic control system used in this embodiment includes a working cylinder, a main oil supply pipeline, a single-cylinder oil supply pipeline, a pressure boost pipeline, and a pressure relief control pipeline, where the main oil supply pipeline and the single-cylinder oil supply pipeline both supply pressure oil through an oil tank.

The number of the working oil cylinders is six, and the working oil cylinders are respectively a right cylinder 3, a front cylinder 4, an upper cylinder 5, a left cylinder 6, a rear cylinder 7 and a lower cylinder 8, wherein the right cylinder 3, the front cylinder 4 and the upper cylinder 5 are positioning cylinders, and the left cylinder 6, the rear cylinder 7 and the lower cylinder 8 are moving cylinders.

The head of the working piston of the positioning cylinder is respectively provided with a return position positioning snap ring, when in return stroke, the piston touches the positioning snap ring to stop, and the position of the end face of the top hammer on the piston, which is far away from the origin of the coordinate center of the press, is 1/2 of the side length of the hexagonal synthetic block to be synthesized.

During the return stroke, the working piston of the moving cylinder can return to the bottom so as to pull open the space to take and place the hexagonal composite block.

The number of the single-cylinder oil supply pipelines is six, the single-cylinder oil supply pipelines correspond to the working oil cylinders one by one, oil inlets of the working oil cylinders are connected with oil outlets of the corresponding single-cylinder oil supply pipelines, and oil outlets of the working oil cylinders are connected with oil return ports of the main oil supply pipelines through balance pipelines.

The oil inlet of the single-cylinder oil supply pipeline is provided with a single-cylinder check valve, the oil inlet of the single-cylinder check valve is connected with the main oil supply pipeline, the oil outlet of the single-cylinder check valve is connected with the oil inlet of the corresponding single-cylinder oil supply pipeline, the single-cylinder oil supply pipeline comprises a single-cylinder reversing valve, the opening B of the single-cylinder reversing valve is connected with the working oil cylinder through an ultrahigh pressure hydraulic control check valve, the opening P of the single-cylinder reversing valve is connected with the main oil supply pipeline, and the opening T of the single-cylinder reversing valve is connected with the oil tank.

The single-cylinder check valve 23, the single-cylinder reversing valve 16 and the ultrahigh-pressure pilot-controlled check valve 10 form an oil supply pipeline of the right cylinder 3;

the single-cylinder check valve 24, the single-cylinder reversing valve 17 and the ultrahigh pressure hydraulic control check valve 11 form an oil supply pipeline of the front cylinder 4;

the single-cylinder check valve 25, the single-cylinder reversing valve 18 and the ultrahigh-pressure pilot-controlled check valve 12 form an oil supply pipeline of the upper cylinder 5;

the single-cylinder check valve 26, the single-cylinder reversing valve 19 and the ultrahigh-pressure hydraulic control check valve 13 form an oil supply pipeline of the left cylinder 6;

the single-cylinder check valve 27, the single-cylinder reversing valve 20 and the ultrahigh-pressure pilot-controlled check valve 14 form an oil supply pipeline of the rear cylinder 7;

the single-cylinder check valve 28, the single-cylinder reversing valve 21 and the ultrahigh-pressure pilot-controlled check valve 15 form an oil supply pipeline of the lower cylinder 8.

The main oil supply pipeline comprises a main oil pump and a main reversing valve 35, an oil inlet of the main oil pump is connected with an oil tank, an oil outlet of the main oil pump is connected with a port P of the main reversing valve 35, a port A of the main reversing valve 35 is respectively connected with oil inlets from the single-cylinder one-way valve 23 to the single-cylinder one-way valve 28, a port B of the main reversing valve 35 is connected with the balance pipeline, and oil outlets of the main oil pump are respectively connected with six pressurizing pipelines through a pressurizing reversing valve 31; the main oil pump comprises a main oil pump 45 and a main oil pump 46 which are connected in parallel, a main oil supply one-way valve 39 is arranged at an oil outlet of the main oil pump 45, a main oil supply one-way valve 40 is arranged at an oil outlet of the main oil pump 46, an oil outlet of the main oil supply one-way valve 39 is respectively connected with a P port of the pressurization reversing valve 31 and a P port of the main reversing valve 35, and an oil outlet of the main oil supply one-way valve 40 is respectively connected with the P port of the pressurization reversing valve 31 and the P port of the main reversing valve 35.

The number of the pressurization pipelines is six and the pressurization pipelines correspond to the working oil cylinder and the single-cylinder oil supply pipeline one by one. The pressurizing pipeline comprises a reciprocating supercharger, and an electromagnetic valve is arranged in the reciprocating supercharger.

Six reciprocal booster solenoid valve P mouths connect the B mouth of pressure boost switching-over valve 31, and six reciprocal booster high pressure plunger oil drain ports are parallelly connected to the export of superhigh pressure check valve, and six reciprocal booster solenoid valve T mouths are parallelly connected to the entry of superhigh pressure pilot operated check valve, and the low pressure piston oil extraction of reciprocal booster merges the superhigh pressure pilot operated check valve entry through reciprocal booster solenoid valve T mouth outflow.

The oil outlet of the high-pressure plunger of the reciprocating supercharger 51 is connected with the oil inlet of the lower cylinder 8;

the oil outlet of the high-pressure plunger of the reciprocating supercharger 52 is connected with the oil inlet of the left cylinder 6;

the oil outlet of the high-pressure plunger of the reciprocating supercharger 53 is connected with the oil inlet of the front cylinder 4;

the oil outlet of the high-pressure plunger of the reciprocating supercharger 54 is connected with the oil inlet of the rear cylinder 7;

the oil outlet of the high-pressure plunger of the reciprocating supercharger 55 is connected with the oil inlet of the upper cylinder 5;

the oil outlet of the high-pressure plunger of the reciprocating supercharger 56 is connected with the oil inlet of the right cylinder 3.

A pressure sensor 1 and a pressure gauge 2 are arranged on a pipeline between an oil outlet of a high-pressure plunger of the reciprocating booster 54 and an oil inlet of the rear cylinder 7.

The invention adopts six reciprocating superchargers with the same structure and size, namely a reciprocating supercharger 51 to a reciprocating supercharger 56, and the six reciprocating superchargers are respectively connected into hydraulic pipelines of six working oil cylinders, wherein the one-way oil discharge quantity Qi = S multiplied by L of the reciprocating movement of the reciprocating superchargers, wherein S represents the area of a piston, L represents the movement stroke of the piston, and i = 51-56. Because S and L of the six reciprocating superchargers are completely equal, the discharge capacities Q51-Q56 of the six reciprocating superchargers are equal, and the electro-hydraulic control system for controlling the valves of the hydraulic oil cylinder controls the electromagnetic directional valves 14 CT-19 CT from the reciprocating superchargers 51 to the reciprocating superchargers 56 to be switched on and off at the same rhythm, so that pistons of the six reciprocating superchargers can synchronously reciprocate to respectively supply oil to the six working oil cylinders with equal capacity, and the pistons in the six working oil cylinders are pushed to accurately displace synchronously.

The balance pipeline comprises a balance valve 22 and an overflow valve 37, an oil inlet of the balance valve 22 is respectively connected with oil outlets of the six working oil cylinders, and an oil outlet of the balance valve 22 is respectively connected with a port B of the main reversing valve 35 and the overflow valve 37.

And an executing element of the ultrahigh pressure hydraulic control one-way valve adopts a control oil pump to perform oil supply control. The ultrahigh pressure hydraulic control one-way valve oil supply loop comprises a control oil pump 47, a control one-way valve 41 and a control reversing valve 36, wherein an oil inlet of the control oil pump 47 is connected with an oil tank, an oil outlet of the control oil pump 47 is connected with an oil inlet of the control one-way valve 41, an oil outlet of the control one-way valve 41 is connected with a port P of the control reversing valve 36, a port A of the control reversing valve 36 is respectively connected with oil outlets of executing elements of the six ultrahigh pressure hydraulic control one-way valves, and a port B of the control reversing valve 36 is respectively connected with oil inlets of the executing elements of the six ultrahigh pressure hydraulic control one-way valves.

The pressure relief control pipeline comprises a two-position communication valve 9, an unloading reversing valve 29, an ultrahigh pressure servo pressure relief valve 30 and an electromagnetic unloading overflow valve 38, an oil inlet of the two-position communication valve 9 is respectively connected with oil inlets of six working cylinders, an oil outlet of the two-position communication valve 9 is connected with an oil tank through the ultrahigh pressure servo pressure relief valve 30, an oil inlet of an actuating element of the two-position communication valve 9 is connected with a port B of the unloading reversing valve 29, an oil outlet of the actuating element of the two-position communication valve 9 is connected with a port A of the unloading reversing valve 29, a port P of the unloading reversing valve 29 is connected with the oil tank through the electromagnetic unloading overflow valve 38, and a port P of the unloading reversing valve 29 is connected with an oil outlet of a control one-way valve 41.

Factor analysis affecting six-cylinder synchronization:

the cylinder diameters of the six working cylinders are the same in size, so that the accuracy of synchronous advancing of the six-cylinder piston is determined by the accuracy of oil supply of six cylinders with equal flow. By using ohm's law of circuit analysis, the expression formula of the hydraulic oil flow entering the oil cylinder to push the piston to advance is as follows:

Q = P/Ri （1）

in the formula (1), Q represents the flow rate of hydraulic oil, P represents the oil pressure, and Ri represents the hydraulic resistance of the hydraulic circuit of the working cylinder.

Because the oil supply of the six cylinders is the same hydraulic source, namely the pressure P in the six cylinders is the same, the motion synchronization of the six-cylinder pistons can be controlled only by controlling the hydraulic resistances R1-R6 of the six working oil cylinders to be the same.

The hydraulic resistance R analysis of the oil cylinder loop is shown as a formula (2):

R = Rj + Rg + Rm + Rw + Rf + Rb （2）

the parameters in equation (2) are explained as follows:

rj: the throttling resistance of the hydraulic system throttling valve; for adjusting the synchronization;

rg: the pipeline resistance of the hydraulic oil pipe; because the six cylinders are different in position, Rg is different when the lengths of oil pipes are different;

rm: piston frictional resistance, frictional resistance generated by piston gravity and the frictional force generated by the gravity direction and the elasticity of the rubber sealing ring; due to the fact that the six cylinders are different in position and different in corresponding gravity direction and due to the influences of size deviation of the sealing ring and processing size deviation of the sealing groove, Rm of the six cylinders are different;

rw: resistance by piston mass; the six cylinder piston is mounted in a position such that the direction of gravity is different from the direction of piston movement, resulting in a difference in Rw, in particular the upper cylinder 5 is the most different from the lower cylinder 8, whereas the front cylinder 4, the rear cylinder 7, the left cylinder 6 and the right cylinder 3 have Rw = 0.

Rf: resistance generated by extrusion deformation of the synthetic block; the synthetic block is an assembly part with an anisotropic structure, and the six-cylinder piston anvil is extruded to produce different strain stresses in six directions, so that the Rf values of the six cylinders are different, and the Rf value is rapidly increased in the process of increasing the extrusion pressure.

Rb the back pressure resistance of the six-cylinder rod cavity (i.e. front cavity). Rb difference between the six cylinders is not large and synchronization can be adjusted by installing a back pressure valve.

The common six-side constant pressure synchronous regulation on the market at present comprises the following two types:

the first method comprises the following steps: and (4) installing a throttle valve to regulate Rj to control the six-cylinder piston to synchronously advance.

The advantages are that: the hydraulic system is simple.

The method comprises the following steps: (1) the throttling resistance Rj of the six cylinders generates nonlinear change of hydraulic resistance by the change of oil temperature, and can affect the adjusted synchronization precision; (2) the high-pressure oil is only acted in a liquid filling stage, the high-pressure oil does not pass through a throttle valve in an overpressure stage, and Rj = 0.

And the second method comprises the following steps: a back pressure valve is installed to regulate Rb.

The advantages are that: simple structure and certain function at the initial stage of overpressure.

The method comprises the following steps: with increasing pressure in the overpressure, Rf increases rapidly and the effect of Rb is neglected.

The synchronous control process of the present invention is further described below in conjunction with the above-described hydraulic control system. The embodiment comprises the following steps:

A. and (3) return stroke: returning the pistons of the three positioning cylinders to the positioning rings, namely returning to 1/2 positions with the distance between the end surface of a top hammer installed at the front end of the piston of the positioning cylinder and the origin of the coordinate center of the cubic press as the side length of the hexagonal synthetic block to be processed, and returning the pistons of the three moving cylinders to the bottom;

B. placing a synthetic block: placing the hexagonal synthetic block to be processed into a mold, and enabling the hexagonal synthetic block to be processed to be tightly attached to the end face of a top hammer arranged at the front end of the pistons of the three positioning cylinders;

C. idle-in and pause:

air admission: the pistons of the three moving cylinders move forward to the original point position of the coordinate center of the cubic press, when the front end surface of the anvil of the moving cylinder contacts the synthetic block, a travel switch or a displacement sensor corresponding to the end surface of the anvil of the moving cylinder sends a signal, and an electro-hydraulic control system of the cubic press enables the piston corresponding to the moving cylinder to stop moving forward;

pausing: when all the three moving cylinder pistons move forward in place and stop moving, starting pause timing, wherein the pause time is 1-10 s;

D. after the pause timing is finished, the working oil cylinder is synchronously filled with liquid through the reciprocating supercharger, and the reciprocating supercharger enters an equal-capacity conversion working mode; after the time is suspended, the pistons of the six working oil cylinders move forwards simultaneously to extrude the composite block.

The specific process is as follows:

d 1: the electromagnet 12CT in the pressure boosting reversing valve 31 is electrified and attracted, pressure oil of the main oil pump 45 and the main oil pump 46 respectively enters a port P of an electromagnetic valve of a reciprocating booster 51 to a port P of an electromagnetic valve of a reciprocating booster 56 through the pressure boosting reversing valve 31, and the pressure oil enters a left port of the reciprocating booster through a port A of the electromagnetic valve of the reciprocating booster and pushes a piston of the reciprocating booster to move right;

d 2: the right-going reciprocating booster piston extrudes the oil in the right cavity of the reciprocating booster piston through a B port and a T port of the solenoid valve of the reciprocating booster and flows to an oil pipe connected with the B port of the single-cylinder reversing valve 16 to the single-cylinder reversing valve 21;

d 3: the electromagnets of the single-cylinder reversing valve 16 to the single-cylinder reversing valve 21 are attracted, meanwhile, the openings B of the single-cylinder reversing valve 16 to the single-cylinder reversing valve 21 are respectively blocked by the single-cylinder one-way valve 23 to the single-cylinder one-way valve 28, and the pressure oil pressed out by the reciprocating supercharger moves upwards to pass through the ultrahigh pressure hydraulic control one-way valve 10 to the ultrahigh pressure hydraulic control one-way valve 15 and enters the corresponding working oil cylinder;

d 4: the pressure oil flowing in by the ultrahigh pressure hydraulic control one-way valve pushes the corresponding working oil cylinder piston to move forwards synchronously, and simultaneously, the pressure oil discharged by the high-pressure plunger at the right end of the reciprocating supercharger flows into the corresponding working oil cylinder through the oil pipe and is converged with the oil discharged by the piston of the reciprocating supercharger to push the piston to move forwards together, namely the pressure oil discharged by the high-pressure plunger at the right end of the reciprocating supercharger flows into the corresponding working oil cylinder through the oil pipe and is converged with the pressure oil flowing in by the ultrahigh pressure hydraulic control one-way valve to push the piston of the working oil cylinder to move forwards together;

d 5: when the piston of the reciprocating supercharger moves right in place, the electromagnet in the reciprocating supercharger is electrified and attracted, the electromagnetic valve of the reciprocating supercharger is reversed, pressure oil in the reciprocating supercharger enters the oil port at the right end of the reciprocating supercharger from the port P of the electromagnetic valve of the reciprocating supercharger to the port B of the electromagnetic valve of the reciprocating supercharger, and the piston of the reciprocating supercharger is pushed to move left; the reciprocating supercharger moves right to the right position, a travel switch arranged at the end head of the reciprocating supercharger sends a signal to an electro-hydraulic control system, and the electro-hydraulic control system controls a piston to stop or is set by the electro-hydraulic control system through preset time;

d 6: the left-going reciprocating booster piston extrudes oil in a left cavity of the reciprocating booster piston, the extruded pressure oil passes through an opening A of the reciprocating booster electromagnetic valve to an opening T of the reciprocating booster electromagnetic valve, then enters the working oil cylinder through the corresponding ultrahigh pressure hydraulic control one-way valve, and then is converged with the oil extruded by the left high-pressure plunger of the reciprocating booster to push the piston of the corresponding working oil cylinder to synchronously move forward until the charging pressure of the working oil cylinder reaches a preset hydraulic threshold; the preset hydraulic threshold value is 5 MPa-10 MPa; preferably 5MPa, 8MPa or 10 MPa;

d 7: when the liquid filling pressure of the six working oil cylinders reaches a preset hydraulic threshold, the liquid filling action is finished, and the six working oil cylinders are switched to overpressure operation.

In the liquid charging stage of the press, oil discharged by a high-pressure plunger of the reciprocating supercharger is connected in parallel to an outlet of the ultrahigh-pressure one-way valve, oil discharged by a low-pressure piston of the reciprocating supercharger flows out of a T port of an electromagnetic valve of the reciprocating supercharger and is connected in parallel to an inlet of the ultrahigh-pressure one-way valve, high-pressure oil and low-pressure oil of the reciprocating supercharger are simultaneously discharged into a working oil cylinder in a high-precision and quantitative mode, the oil cylinder piston can move quickly and accurately, and at the moment, the reciprocating supercharger works in an equal-volume conversion mode. When the T port of the electromagnetic valve of the reciprocating supercharger discharges oil to the oil tank, the reciprocating supercharger works in a supercharging mode with constant volume and supercharging ratio.

The invention utilizes the characteristics of quantitative oil discharge and large flow of a low-pressure piston of the reciprocating booster to introduce large flow of oil into a working oil cylinder so as to realize the quick synchronous control of a press in a liquid charging section.

The present embodiment takes the following parameters as an example to perform verification of the result: the pressure ratio of the reciprocating supercharger is 1:7, the reciprocating supercharger works in a constant volume conversion mode in a liquid filling stage, the oil flow for pushing the low-pressure piston is 7L, the pressure is 10MPa, and the oil discharge of the low-pressure piston is 7L-1L = 6L; the output flow of the pressurized oil discharge of the high-pressure plunger is 1L, the combined flow output is 1L +6L =7L, the output pressure is 1:1, the conversion can reach 10MPa, and the quick synchronous liquid filling is realized.

E. The six cylinders synchronously generate overpressure, and the reciprocating supercharger enters an overpressure working mode with constant volume and pressure ratio: when the charging pressure of the working oil cylinder reaches a preset hydraulic threshold, high-pressure oil is injected into the six cylinders through the six-way flow divider valve, the piston anvil is pushed to further extrude the synthesized block until the pressure of the working oil cylinder reaches a preset ultrahigh pressure threshold, wherein the ultrahigh pressure threshold is 40-120 MPa, and preferably 40, 100 or 120 MPa.

The specific process is as follows:

e 1: the single-cylinder reversing valve 16 to the single-cylinder reversing valve 21 are powered off, the electromagnet of the pressurization reversing valve 31 is powered on and attracted, and pressure oil of the main oil pump enters the P ports of the six reciprocating booster electromagnetic valves through the pressurization reversing valve 31;

e 2: pressure oil enters a left oil port of the reciprocating supercharger through an electromagnetic valve port A of the reciprocating supercharger and pushes a piston of the reciprocating supercharger to move right;

e 3: the oil in the right cavity of the piston of the reciprocating supercharger is pushed by the right piston and is extruded out through a port B of the electromagnetic valve of the reciprocating supercharger and a port T of the electromagnetic valve of the reciprocating supercharger;

e 4: the oil pressed out from the T port of the electromagnetic valve of the reciprocating supercharger flows to the B port of the corresponding single-cylinder reversing valve and returns to the oil tank through the T port of the single-cylinder reversing valve;

e 5: pressurized oil discharged by a high-pressure plunger at the right end of the reciprocating supercharger flows into a corresponding working oil cylinder through an oil pipe to push a piston to move forwards, a hexagonal composite block is compressed, and the oil pressure in the working oil cylinder rises along with the increase of compression load;

e 6: when the piston of the reciprocating supercharger moves right in place, the electromagnet of the reciprocating supercharger is powered on and closed, the electromagnetic valve of the reciprocating supercharger is reversed, pressure oil enters the oil port at the right end of the reciprocating supercharger and pushes the piston of the reciprocating supercharger to move left after passing through the P port of the electromagnetic valve of the reciprocating supercharger to the B port; the reciprocating supercharger moves right to the right position, a travel switch arranged at the end head of the reciprocating supercharger sends a signal to an electro-hydraulic control system, and the electro-hydraulic control system controls a piston to stop or is set by the electro-hydraulic control system through preset time;

e 7: the oil in the left cavity of the reciprocating booster piston is pressed out and passes through an A port to a T port of the reciprocating booster electromagnetic valve, and then the oil pressed out from the T port of the reciprocating booster electromagnetic valve returns to the oil tank through a corresponding single-cylinder reversing valve;

e 8: high-pressure oil pressurized and extruded by a high-pressure plunger at the left end of the reciprocating supercharger enters a corresponding working oil cylinder to carry out overpressure so as to push a piston to move forwards synchronously;

e 9: the interval on-off reversing of the electromagnetic valve of the reciprocating booster is controlled by the electro-hydraulic control system, so that the piston of the reciprocating booster swings left and right, and the oil pressurized in a reciprocating manner continuously flows into the corresponding working oil cylinder until the pressure of the oil cylinder is increased to the synthetic working pressure of 120MPa, and then the oil cylinder stops.

When the charging pressure is below 10MPa, the oil supply pressure of the main oil pump can meet the requirement, and the reciprocating booster is not needed for boosting, so that the quantitative oil discharge and the high-pressure oil discharge of the piston of the reciprocating booster can be combined and injected into the working oil cylinder, and the flow and the pressure are both 1:1 conversion; in the overpressure working section, the final pressure needs to reach the ultrahigh pressure of more than 100MPa, so that the reciprocating supercharger needs to rely on the oil discharge overpressure of the high-pressure plunger, the oil discharge of the piston of the reciprocating supercharger needs to return to an oil tank, the conversion of the pressure of 7:1 and the flow of 1:7 is realized, and the supercharging effect is ensured.

F. Pressure maintaining and pressure relief:

pressure maintaining: maintaining ultrahigh pressure synthesis pressure, introducing large current into the synthesis block for heating, and synthesizing diamond at high temperature and high pressure;

pressure relief: and (4) after the high-temperature and high-pressure synthesis is finished, stopping heating, and opening the ultrahigh-pressure servo pressure relief valve to release the pressure of the six working oil cylinders.

G. And (3) returning and taking out a synthetic block: when the pressure of the six-cylinder oil pressure relief is reduced to be below 4MPa, the six working oil cylinder pistons return, and the processed synthetic block workpiece is taken out.

The invention is characterized in that:

(1) due to the high volumetric efficiency of the reciprocating supercharger and the incompressibility of hydraulic oil, the fluctuation of the motion load of the pistons of the six oil cylinders and the change of oil temperature, the displacement change of the reciprocating supercharger is not influenced, namely the synchronous motion precision of the six working oil cylinders is not influenced, the synchronous displacement precision of the six cylinders is improved, and the synchronous control precision can reach 0.1 mm-0.2 mm;

(2) the reciprocating supercharger not only plays a role in synchronous displacement control of six-cylinder equal-volume oil supply, but also is an ultrahigh pressure oil source, and can load the oil pressure of the working oil cylinder to 120MPa of working pressure;

(3) the six-cylinder synchronous displacement control device can control the synchronous displacement of the six working cylinders in the liquid filling process of the cubic press, can also accurately control the synchronous displacement of the six cylinders in the overpressure process, and has more flexibility and practicability;

(4) according to the actual size deviation in the XYZ three coordinate directions after the regular and hexagonal raw material synthetic block is pressed, the reciprocating times of the corresponding working oil cylinders and the reciprocating superchargers can be increased and decreased through an electro-hydraulic control system to correct, or the working times of the corresponding reciprocating superchargers can be corrected on line in real time according to synchronous motion deviation detected by displacement sensors arranged on the pistons of the six working oil cylinders, and the control precision is further improved;

(5) each working oil cylinder is provided with an independent reciprocating booster, and the six working oil cylinders can be respectively independently and accurately controlled according to the process requirements to generate different working pressures and displacements;

(6) the electro-hydraulic control system realizes the synchronization control digitization, so that the control operation is simpler and more reliable.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that various changes, modifications and substitutions can be made therein without departing from the spirit and scope of the embodiments of the present invention.

Claims

1. The utility model provides a cubic press hydraulic cylinder synchronous control method, cubic press hydraulic system include six work hydro-cylinders, are three location jar and three movable cylinder respectively, and the homogeneous one-to-one correspondence is connected with single cylinder oil supply line on every work hydro-cylinder, and the main oil supply line is connected respectively to six way single cylinder oil supply line's oil inlet, and the direction when flowing to work hydro-cylinder by hydraulic oil on each way single cylinder oil supply line is equipped with single cylinder switching-over valve and superhigh pressure liquid accuse check valve, its characterized in that in proper order: the method comprises the following steps:

B. placing a hexagonal synthesis block to be processed: placing the hexagonal synthetic block to be processed into the positioning cylinder, and enabling the hexagonal synthetic block to be processed to be tightly attached to the end face of a top hammer arranged at the front end of the positioning cylinder piston;

C. idle-in and pause: advancing each movable cylinder piston to the original point position of the coordinate center of the cubic press until the front end surface of the anvil of the movable cylinder contacts the hexagonal composite block to be processed, and advancing the movable cylinder piston to the proper position and stopping moving; when all the three moving cylinder pistons advance to the right position, starting to time the pause time;

d 2: cutting off the six single-cylinder oil supply pipelines from the main oil pump to separate the six single-cylinder oil supply pipelines from each other;

d 3: oil discharge ports of high-pressure plungers of the six reciprocating superchargers are respectively connected with outlets of single-cylinder reversing valves corresponding to the six reciprocating superchargers, T ports of electromagnetic valves of the six reciprocating superchargers are respectively connected with inlets of ultrahigh-pressure hydraulic control one-way valves corresponding to the six reciprocating superchargers, and low-pressure piston oil discharge of the six reciprocating superchargers flows out to inlets of the ultrahigh-pressure hydraulic control one-way valves corresponding to the six reciprocating superchargers through the T ports of the electromagnetic valves of the reciprocating superchargers;

d 4: high-pressure and low-pressure oil outlet of the six reciprocating superchargers are simultaneously and quantitatively injected into the corresponding working oil cylinders, so that the pistons of the six working oil cylinders rapidly and synchronously move until the charging pressure of the working oil cylinders reaches a preset hydraulic threshold;

E. the six cylinders synchronously generate overpressure, and the reciprocating supercharger enters an overpressure working mode with constant volume and pressure ratio: when the charging pressures of the six working oil cylinders reach a preset hydraulic threshold, the six reciprocating superchargers start pumping oil, high-pressure oil is respectively injected into the six working oil cylinders through the six-way flow divider valve, and a piston anvil is pushed to further extrude the hexagonal composite block to be processed until the pressures of the six working oil cylinders reach a preset ultrahigh pressure threshold; the specific process is as follows:

e 2: cutting off single-cylinder oil supply pipelines corresponding to the six working oil cylinders from the main oil pump, so that the six single-cylinder oil supply pipelines are mutually isolated;

e 3: the oil discharge ports of the high-pressure plungers of the six reciprocating superchargers are connected in parallel and then connected to the outlet of the single-cylinder reversing valve, the T ports of the electromagnetic valves of the six reciprocating superchargers are respectively connected to the inlets of the ultrahigh-pressure hydraulic control one-way valves corresponding to the T ports, at the moment, the six single-cylinder reversing valves in the six single-cylinder oil supply pipelines are all electrified and sucked, and the oil discharged by the low-pressure pistons of the six reciprocating superchargers flows out from the T ports of the electromagnetic valves of the reciprocating superchargers and is connected with the T ports of the corresponding six single-cylinder reversing valves and returns to an oil tank;

e 5: the alternate on-off reversing of six reciprocating booster electromagnetic valves is controlled by an electro-hydraulic control system, so that a low-pressure piston of a reciprocating booster swings left and right, and further reciprocating boosted oil continuously flows into a corresponding working oil cylinder until the pressure of the working oil cylinder is increased to a preset ultrahigh pressure threshold value and then stops;

F. pressure maintaining and pressure relief: maintaining ultrahigh pressure synthesis pressure, simultaneously introducing large current into the hexagonal synthesis block to be processed for heating, synthesizing diamond at high temperature and high pressure, then stopping heating after the high temperature and high pressure synthesis is finished, opening the ultrahigh pressure servo relief valve, and releasing the pressure of the six working oil cylinders.

2. The synchronous control method for the hydraulic oil cylinders of the cubic press according to claim 1, is characterized in that: the specific process of the step d3 is as follows:

d 3.1: the pressure oil enters a left oil port of the reciprocating supercharger and pushes a piston of the reciprocating supercharger to move right, the piston of the reciprocating supercharger moving right flows out the oil pressure of a right cavity of the piston of the reciprocating supercharger and flows to a corresponding single-cylinder oil supply pipeline, and then the oil goes upward to enter a corresponding working oil cylinder through the ultrahigh pressure hydraulic control one-way valve;

d 3.2: the pressure oil flowing out of the ultrahigh pressure hydraulic control one-way valve pushes the corresponding working oil cylinder piston to move forwards synchronously, and meanwhile, the pressure oil discharged by the high-pressure plunger at the right end of the reciprocating supercharger flows into the corresponding working oil cylinder through the oil pipe and is combined with the oil discharged by the piston of the reciprocating supercharger to push the working oil cylinder piston to move forwards together, namely the pressure oil discharged by the high-pressure plunger at the right end of the reciprocating supercharger flows into the corresponding working oil cylinder through the oil pipe and is combined with the pressure oil flowing in by the ultrahigh pressure hydraulic control one-way valve to push the working oil cylinder piston to move forwards together;

d 3.4: the piston of the reciprocating supercharger moves leftwards to discharge the oil pressure of the left cavity of the piston of the reciprocating supercharger and flow the oil pressure into a corresponding single-cylinder oil supply pipeline, and then the oil pressure moves upwards to enter a corresponding working oil cylinder through the ultrahigh-pressure hydraulic control one-way valve;

d 3.5: the pressure oil flowing out of the ultrahigh pressure hydraulic control one-way valve pushes the corresponding working oil cylinder piston to synchronously advance, and meanwhile, the oil pressed out of the left high pressure plunger of the reciprocating supercharger enters the corresponding working oil cylinder and is converged with the pressure oil flowing out of the ultrahigh pressure hydraulic control one-way valve to push the working oil cylinder piston to synchronously advance until the charging pressure of the working oil cylinder reaches a preset hydraulic threshold value.

3. The synchronous control method for the hydraulic oil cylinders of the cubic press according to claim 2, is characterized in that: in the step d3.3, the reciprocating supercharger moves right to the right position, a travel switch arranged on the end head of the reciprocating supercharger sends a signal to an electro-hydraulic control system, and the electro-hydraulic control system controls the piston of the reciprocating supercharger to stop or is set by the electro-hydraulic control system through preset time.

4. The synchronous control method for the hydraulic oil cylinders of the cubic press according to claim 1, is characterized in that: the specific process of the step e3 is as follows:

e 3.2: under the pushing of the piston of the reciprocating supercharger moving to the right, the oil in the right cavity of the piston of the reciprocating supercharger is pressed out and flows to the corresponding single-cylinder oil supply pipeline;

e 3.3: the oil pressed out from the right cavity of the piston of the reciprocating supercharger enters an oil tank through a corresponding single-cylinder oil supply pipeline;

e 3.4: pressurized oil discharged by a high-pressure plunger at the right end of the reciprocating supercharger flows into a corresponding working oil cylinder through an oil pipe to push a working oil cylinder piston to move forwards, the working oil cylinder piston compresses the hexagonal composite block to be processed, and the oil pressure in the working oil cylinder rises along with the increase of compression load;

e 3.6: under the pushing of the piston of the reciprocating supercharger moving left, the oil in the piston left cavity of the reciprocating supercharger is extruded out and enters the corresponding single-cylinder oil supply pipeline;

e 3.7: the oil pressed out from the left cavity of the reciprocating supercharger enters the oil tank through a corresponding single-cylinder oil supply pipeline;

e 10: high-pressure oil pressurized and extruded by a high-pressure plunger at the left end of the reciprocating booster enters the corresponding working oil cylinder to carry out overpressure so as to push the piston of the working oil cylinder to move forwards synchronously.

5. The synchronous control method for the hydraulic oil cylinders of the cubic press according to claim 4, is characterized in that: in the step e3.5, the reciprocating supercharger moves right to the right position, a travel switch arranged on the end head of the reciprocating supercharger sends a signal to an electro-hydraulic control system, and the electro-hydraulic control system controls the piston of the reciprocating supercharger to stop or is set by the electro-hydraulic control system through preset time.

6. The synchronous control method for the hydraulic oil cylinders of the cubic press according to claim 1, is characterized in that: the pause time in the step C is 1 s-10 s.

7. The synchronous control method for the hydraulic oil cylinders of the cubic press according to claim 1, is characterized in that: the method for cutting off the six single-cylinder oil supply pipelines from the main oil pump in the steps d2 and e2 is to install a one-way valve between each single-cylinder oil supply pipeline and the main oil pump, wherein the flow direction of the one-way valve is that the main oil pump flows to the working oil cylinder.

8. The synchronous control method for the hydraulic oil cylinders of the cubic press according to claim 1, is characterized in that: in the step C, the detection method that the front end face of the movable cylinder top hammer is contacted with the hexagonal synthetic block to be processed adopts the mode that a travel switch or a displacement sensor is arranged on the end face of the movable cylinder top hammer.

9. The synchronous control method for the hydraulic oil cylinders of the cubic press according to any one of claims 1 or 2, which is characterized in that: the preset hydraulic threshold is 5 MPa-10 MPa.

10. The synchronous control method for the hydraulic oil cylinders of the cubic press according to any one of claims 1 or 4, which is characterized in that: the preset ultrahigh pressure threshold is 40-120 MPa.