Multi-stage booster safety coupling hydraulic system for liquid-filled forming hydraulic press

Abstract

The present invention discloses a multi-stage pressurization safety coupling hydraulic system of a liquid-filled forming hydraulic press, which mainly includes a first electromagnetic cartridge valve, a first check valve, a second electromagnetic cartridge valve, a third electromagnetic cartridge valve, a fourth electromagnetic cartridge valve, a second check valve, a fifth electromagnetic cartridge valve, a safety valve, a pressure regulating cartridge valve, a third check valve, a sixth electromagnetic cartridge valve, a seventh electromagnetic cartridge valve, a first check valve, a second check valve, a first pressure sensor, and a second pressure sensor. The present invention can realize multi-stage speed pressurization of a slider of a liquid-filled forming hydraulic press, thereby improving production efficiency; at the same time, it has multi-stage support and multiple safety coupling hydraulic oil circuits, which improves the safety level of the system.

Description

Technical Field

[0001] The invention relates to a hydraulic system of a liquid-filled forming hydraulic press, in particular to a multi-stage pressurized safety coupling hydraulic system of a liquid-filled forming hydraulic press. Background Art

[0002] The liquid-filled molding hydraulic press is in a long-term mold-closing and pressure-maintaining state when working. Increasing the running speed of the slider before mold closing and the pressurization speed after mold closing are effective means to improve production efficiency. Not only is the mold closed for a long time, but the mold is also filled with ultra-high-pressure liquid media for workpiece forming. The reliable stability of the system is particularly important for safe production. Summary of the invention

[0003] The purpose of the present invention is to provide a multi-stage pressurization safety coupling hydraulic system for a liquid-filled molding hydraulic press, which can achieve multi-stage hydraulic cylinder pressurization to improve production efficiency; at the same time, the oil circuit that drives the hydraulic cylinder to move has multi-stage support and safety coupling, so that production safety is reliably guaranteed.

[0004] The technical solution of the present invention is as follows:

[0005] The present invention mainly includes a first electromagnetic cartridge valve, a first check valve, a second electromagnetic cartridge valve, a third electromagnetic cartridge valve, a fourth electromagnetic cartridge valve, a second check valve, a fifth electromagnetic cartridge valve, a safety valve, a pressure regulating cartridge valve, a third check valve, a sixth electromagnetic cartridge valve, a seventh electromagnetic cartridge valve, a first check valve, a second check valve, a first pressure sensor, and a second pressure sensor; wherein, an oil source oil inlet PS is connected to an A port of the first electromagnetic cartridge valve, an oil inlet of the first check valve, and an A port of the second electromagnetic cartridge valve, an oil outlet of the first check valve is connected to a P port of a pilot electromagnetic valve of the first electromagnetic cartridge valve, a B port of the second electromagnetic cartridge valve is connected to an A port of the third electromagnetic cartridge valve, and an A port of the fourth electromagnetic cartridge valve, an oil outlet of a pilot relief valve of the third electromagnetic cartridge valve is connected to an A port of the pilot electromagnetic valve of the first electromagnetic cartridge valve, a B port of the fourth electromagnetic cartridge valve is connected to an oil inlet of the second check valve, and an A port of the fifth electromagnetic cartridge valve, and a second pressure sensor. The oil outlet of the one-way valve is connected to the P port of the pilot solenoid valve of the fourth solenoid cartridge valve, the B port of the fifth cartridge valve is connected to the oil inlet of the safety valve and the return oil port BC of the hydraulic cylinder, the B port of the first solenoid cartridge valve is connected to the A port of the pressure regulating cartridge valve, the A port of the sixth solenoid cartridge valve, and the A port of the seventh solenoid cartridge valve, the oil inlet of the third one-way valve is connected to the X port of the pressure regulating cartridge valve, the oil outlet of the third one-way valve is connected to the B port of the pilot solenoid valve of the fourth solenoid cartridge valve, and the The B port of the magnetic cartridge valve is connected to the B port of the second one-way cartridge valve, the detection port of the first pressure sensor, and the first-stage hydraulic cylinder pressing oil port A1, the B port of the seventh solenoid cartridge valve is connected to the A port of the first one-way cartridge valve, the B port of the first one-way cartridge valve is connected to the A port of the second one-way cartridge valve, the detection port of the second pressure sensor, and the second-stage hydraulic cylinder pressing oil port A2, and the hydraulic oil tank is connected to the B port of the third solenoid cartridge valve, the oil outlet of the safety valve, and the B port of the pressure regulating cartridge valve.

[0006] Furthermore, the multi-stage pressurized safety coupling hydraulic system of the liquid-filled forming hydraulic press of the present invention is set as follows for the hydraulic cylinder control mode:

[0007] a) Slide quickly goes down: the pilot solenoid valves of the first, third, fourth and fifth solenoid valves are powered on, and the pilot solenoid valves of the second, sixth and seventh solenoid valves are powered off; the oil ports A to B of the first, third and sixth solenoid valves are in a conducting state, the oil ports B to A of the fourth and fifth solenoid valves are in a conducting state, and the second and seventh solenoid valves are in a cut-off state; the hydraulic oil from the oil source enters from the oil port PS, passes through the first and sixth solenoid valves, and enters the action chamber of the first-stage pressing hydraulic cylinder from the oil port A1, and the oil path entering the oil port A2 is cut off; the hydraulic oil discharged from the action chamber of the return hydraulic cylinder enters the oil port BC, passes through the fifth, fourth and third solenoid valves, and flows back to the hydraulic oil tank. The slide quickly descends by its own weight.

[0008] b) Slider first-level process: the first solenoid cartridge valve, the fourth solenoid cartridge valve, and the fifth solenoid cartridge valve pilot solenoid valve are energized, and the second solenoid cartridge valve, the third solenoid cartridge valve, the sixth solenoid cartridge valve, and the seventh solenoid cartridge valve pilot solenoid valve are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve and the sixth solenoid cartridge valve are in the conduction state, the third solenoid cartridge valve is in the pressure regulating state, the oil port B to the oil port A of the fourth solenoid cartridge valve and the fifth solenoid cartridge valve are in the conduction state, and the second solenoid cartridge valve and the seventh solenoid cartridge valve are in the cut-off state ; The hydraulic oil from the oil source enters from the oil port PS, passes through the first electromagnetic cartridge valve and the sixth electromagnetic cartridge valve, and enters the working chamber of the first-stage pressing hydraulic cylinder from the oil port A1, and the oil path entering the oil port A2 is cut off; the hydraulic oil discharged from the working chamber of the return hydraulic cylinder enters the oil port BC, passes through the fifth electromagnetic cartridge valve, the fourth electromagnetic cartridge valve, and the third electromagnetic cartridge valve to flow back to the hydraulic oil tank, and the pressure of the working chamber of the return hydraulic cylinder is adjusted by the third electromagnetic cartridge valve, thereby forming a supporting force; the pressing pressure is adjusted by the pilot proportional relief valve of the pressure regulating cartridge valve. The full flow of the system hydraulic oil enters the working chamber of the first-stage pressing hydraulic cylinder, and the slider works at the fastest speed.

[0009] c) Slider secondary operation: When the first pressure sensor detects that the first-stage pressing pressure reaches the set value, the first solenoid cartridge valve, the fourth solenoid cartridge valve, the fifth solenoid cartridge valve, and the seventh solenoid cartridge valve pilot solenoid valve are energized, and the second solenoid cartridge valve, the third solenoid cartridge valve, and the sixth solenoid cartridge valve pilot solenoid valve are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve, the sixth solenoid cartridge valve, and the seventh solenoid cartridge valve are in a conducting state, the third solenoid cartridge valve is in a pressure regulating state, the oil port B to the oil port A of the fourth solenoid cartridge valve and the fifth solenoid cartridge valve are in a conducting state, and the second solenoid cartridge valve is in a cut-off state; the hydraulic oil from the oil source enters from the oil port PS, because the sixth solenoid cartridge valve, the first one-way The cartridge valve is in a one-way conduction state where port A is connected to port B and port B is not connected to port A, so the hydraulic oil enters the lower pressure side of ports A1 and A2 first after passing through the first solenoid cartridge valve. When the pressure on both sides is balanced, the hydraulic oil enters the action chambers of the first and second pressing hydraulic cylinders from the sixth and seventh solenoid cartridge valves and the first one-way cartridge valve respectively; the hydraulic oil discharged from the action chamber of the return hydraulic cylinder enters port BC, flows back to the hydraulic oil tank through the fifth, fourth and third solenoid cartridge valves, and adjusts the pressure of the action chamber of the return hydraulic cylinder through the third solenoid cartridge valve, thereby forming a supporting force; the pressing pressure is adjusted by the pilot proportional relief valve of the pressure regulating cartridge valve. The system hydraulic oil enters the action chambers of the first and second pressing hydraulic cylinders at the same time, and the slider force increase speed reaches the fastest.

[0010] d) Slider return stroke: The pilot solenoid valve of the second solenoid cartridge valve is energized, and the pilot solenoid valves of the first solenoid cartridge valve, the third solenoid cartridge valve, the fourth solenoid cartridge valve, the fifth solenoid cartridge valve, the sixth solenoid cartridge valve, and the seventh solenoid cartridge valve are de-energized; the oil port A to the oil port B of the second solenoid cartridge valve, the fourth solenoid cartridge valve, and the fifth solenoid cartridge valve are in a conducting state, the first solenoid cartridge valve and the third solenoid cartridge valve are in a cut-off state, and the sixth solenoid cartridge valve and the first one-way cartridge valve are in a one-way cut-off state where the oil port B is not connected to the oil port A; the hydraulic oil from the oil source enters from the oil port PS, passes through the second solenoid cartridge valve, the fourth solenoid cartridge valve, and the fifth solenoid cartridge valve, and enters the working chamber of the return hydraulic cylinder from the oil port BC; the hydraulic oil discharged from the working chamber of the primary and secondary pressing hydraulic cylinders flows back to the hydraulic oil tank through the filling valve. The slider is lifted.

[0011] Furthermore, the multi-stage booster safety coupling hydraulic system of the liquid-filled forming hydraulic press of the present invention is characterized in that the hydraulic system has multi-stage safety support and oil circuit safety coupling:

[0012] a) The fourth solenoid cartridge valve and the fifth solenoid cartridge valve form a multi-level safety support for the return hydraulic cylinder action chamber. The hydraulic press slide will lose its safety support only when both valves fail.

[0013] b) The fourth solenoid cartridge valve, the second non-return valve, the pressure regulating cartridge valve and the third non-return valve form a pressing safety coupling circuit. During the pressing process of the slider, the pressure regulating cartridge valve can only build up pressure when the pilot solenoid valve of the fourth solenoid cartridge valve is energized. The pressing safety coupling circuit avoids overpressure in the return action chamber and pipeline during pressing.

[0014] c) The first solenoid cartridge valve, the first non-return valve and the third solenoid cartridge valve form a return safety coupling circuit. During the return process of the slider, the oil outlet of the pilot relief valve of the third solenoid cartridge valve is cut off, and the third solenoid cartridge valve is in a reliable cut-off state. The return safety coupling circuit realizes the switching between the pressure of the return action chamber during the return stroke and the supporting pressure during the pressing stroke, and reduces the risk of return stall due to valve failure.

[0015] d) The sixth solenoid valve, the first one-way valve and the second one-way valve constitute a safety coupling circuit for balancing the pressure of the working chambers of the first-stage and second-stage pressing hydraulic cylinders during pressurization and pressure relief. When the first-stage pressing is switched to the second-stage pressing, the sixth solenoid valve and the first one-way valve are in a one-way conduction state from oil port A to oil port B, and the hydraulic oil preferentially enters the side with lower pressure between oil ports A1 and A2. At the same time, the hydraulic oil on the high-pressure side will not leak back to the low-pressure side. When the pressures on both sides are balanced, the first-stage and second-stage hydraulic cylinders are pressed synchronously. When unloading, the pilot solenoid valve of the sixth solenoid valve is energized, and the oil port B of the sixth solenoid valve is connected to the oil port A. The pilot proportional relief valve of the pressure regulating valve adjusts the pressure relief pressure. The hydraulic oil in the working chamber of the second-stage pressing hydraulic cylinder passes through the second one-way valve and merges with the hydraulic oil in the working chamber of the first-stage pressing hydraulic cylinder to relieve pressure, thereby achieving synchronous pressure relief and avoiding overpressure in the working chamber and pipeline of the hydraulic cylinder caused by asynchronous pressure relief.

[0016] The multi-stage supercharging technology described above is not limited to two stages, and can be expanded to multiple stages.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The multi-stage boosting principle of the present invention realizes the step-by-step increase of the pressing force and synchronous pressure relief. The pressure in the hydraulic cylinder action chamber is automatically balanced without impact when switching between each stage and when the pressure is relieved. The system is safe, reliable and efficient.

[0019] 2. The oil circuit of the hydraulic system of the present invention has multiple action-related couplings, which can provide reliable safety guarantees in each working process of the slider, such as fast descent, pressing, return and hovering. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the hydraulic system principle of the present invention.

[0021] Figure 2 It is a schematic diagram of the principle of an example of the present invention.

[0022] Figure 1 In: 1-first solenoid cartridge valve, 2-first one-way valve, 3-second solenoid cartridge valve, 4-third solenoid cartridge valve, 5-fourth solenoid cartridge valve, 6-second one-way valve, 7-fifth solenoid cartridge valve, 8-safety valve, 9-pressure regulating cartridge valve, 10-third one-way valve, 11-sixth solenoid cartridge valve, 12-seventh solenoid cartridge valve, 13-first one-way cartridge valve, 14-second one-way cartridge valve, 15-first pressure sensor, 16-second pressure sensor.

[0023] Figure 2 Middle: 201-side cylinder, 202-main cylinder, 203-filling valve, 204-slider, 205-oil source. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] See also Figure 1 The present invention mainly includes: a first electromagnetic cartridge valve 1, a first check valve 2, a second electromagnetic cartridge valve 3, a third electromagnetic cartridge valve 4, a fourth electromagnetic cartridge valve 5, a second check valve 6, a fifth electromagnetic cartridge valve 7, a safety valve 8, a pressure regulating cartridge valve 9, a third check valve 10, a sixth electromagnetic cartridge valve 11, a seventh electromagnetic cartridge valve 12, a first check valve 13, a second check valve 14, a first pressure sensor 15, and a second pressure sensor 16; wherein, the oil source inlet PS is connected to the A of the first electromagnetic cartridge valve 1 The oil port of the first one-way valve 2 is connected to the oil inlet of the first one-way valve 2 and the A port of the second solenoid cartridge valve 3. The oil outlet of the first one-way valve 2 is connected to the P port of the pilot solenoid valve of the first solenoid cartridge valve 1. The B port of the second solenoid cartridge valve 3 is connected to the A port of the third solenoid cartridge valve 4 and the A port of the fourth solenoid cartridge valve 5. The oil outlet of the pilot relief valve of the third solenoid cartridge valve 4 is connected to the A port of the pilot solenoid valve of the first solenoid cartridge valve 1. The B port of the fourth solenoid cartridge valve 5 is connected to the oil inlet of the second one-way valve 6 and the A port of the fifth solenoid cartridge valve 7. The oil outlet of the second check valve 6 is connected to the P port of the pilot solenoid valve of the fourth solenoid cartridge valve 5, the B port of the fifth cartridge valve 7 is connected to the oil inlet of the safety valve 8 and the return oil port BC of the hydraulic cylinder, the B port of the first solenoid cartridge valve 1 is connected to the A port of the pressure regulating cartridge valve 9, the A port of the sixth solenoid cartridge valve 11, and the A port of the seventh solenoid cartridge valve 12, the oil inlet of the third check valve 10 is connected to the X port of the pressure regulating cartridge valve 9, the oil outlet of the third check valve 10 is connected to the B port of the pilot solenoid valve of the fourth solenoid cartridge valve 5, the The B port of the cartridge valve 11 is connected to the B port of the second one-way cartridge valve 14, the detection port of the first pressure sensor 15, and the first-stage hydraulic cylinder pressing oil port A1, the B port of the seventh solenoid cartridge valve 12 is connected to the A port of the first one-way cartridge valve 13, the B port of the first one-way cartridge valve 13 is connected to the A port of the second one-way cartridge valve 14, the detection port of the second pressure sensor 16, and the second-stage hydraulic cylinder pressing oil port A2, and the hydraulic oil tank is connected to the B port of the third solenoid cartridge valve 4, the oil outlet of the safety valve 8, and the B port of the pressure regulating cartridge valve 9.

[0026] See also Figure 2 The multi-stage pressurized safety coupling hydraulic system of the liquid-filled forming hydraulic press of the present invention is set as follows for the hydraulic cylinder control mode:

[0027] a) Slider 204 moves down quickly: the pilot solenoid valves of the first solenoid cartridge valve 1, the third solenoid cartridge valve 4, the fourth solenoid cartridge valve 5, and the fifth solenoid cartridge valve 7 are energized, and the pilot solenoid valves of the second solenoid cartridge valve 3, the sixth solenoid cartridge valve 11, and the seventh solenoid cartridge valve 12 are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve 1, the third solenoid cartridge valve 4, and the sixth solenoid cartridge valve 11 are in a conducting state, and the oil port B to the oil port A of the fourth solenoid cartridge valve 5 and the fifth solenoid cartridge valve 7 are in a conducting state. The hydraulic oil from the oil source 205 enters from the oil port PS, passes through the first electromagnetic cartridge valve 1 and the sixth electromagnetic cartridge valve 11, and enters the rodless chamber of the side cylinder 201 from the oil port A1, and the oil path to the oil port A2 is cut off; the hydraulic oil discharged from the rod chamber of the side cylinder 201 enters the oil port BC, passes through the fifth electromagnetic cartridge valve 7, the fourth electromagnetic cartridge valve 5, and the third electromagnetic cartridge valve 4, and flows back to the hydraulic oil tank. The slider 204 is quickly lowered by its own weight.

[0028] b) Slider 204 first-level process: the pilot solenoid valves of the first solenoid cartridge valve 1, the fourth solenoid cartridge valve 5, and the fifth solenoid cartridge valve 7 are energized, and the pilot solenoid valves of the second solenoid cartridge valve 3, the third solenoid cartridge valve 4, the sixth solenoid cartridge valve 11, and the seventh solenoid cartridge valve 12 are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve 1 and the sixth solenoid cartridge valve 11 are in the conduction state, the third solenoid cartridge valve 4 is in the pressure regulating state, the oil port B to the oil port A of the fourth solenoid cartridge valve 5 and the fifth solenoid cartridge valve 7 are in the conduction state, the second solenoid cartridge valve 3 and the seventh solenoid cartridge valve 1 2 is the cut-off state; the hydraulic oil from the oil source 205 enters from the oil port PS, passes through the first electromagnetic cartridge valve 1 and the sixth electromagnetic cartridge valve 11, and enters the rodless chamber of the side cylinder 201 from the oil port A1, and the oil path entering the oil port A2 is cut off; the hydraulic oil discharged from the rod chamber of the side cylinder 201 enters the oil port BC, passes through the fifth electromagnetic cartridge valve 7, the fourth electromagnetic cartridge valve 5, and the third electromagnetic cartridge valve 4 and flows back to the hydraulic oil tank, and the pressure of the rod chamber of the side cylinder 201 is adjusted by the third electromagnetic cartridge valve 4, thereby forming a supporting force; the pressing pressure is adjusted by the pilot proportional relief valve of the pressure regulating cartridge valve 9. The full flow of the system hydraulic oil enters the rodless chamber of the side cylinder 201, and the slider 204 works at the fastest speed.

[0029] c) Secondary operation of the slider 204: When the first pressure sensor 15 detects that the rodless chamber pressure of the side cylinder 201 reaches the set value, the pilot solenoid valves of the first solenoid cartridge valve 1, the fourth solenoid cartridge valve 5, the fifth solenoid cartridge valve 7, and the seventh solenoid cartridge valve 12 are energized, and the pilot solenoid valves of the second solenoid cartridge valve 3, the third solenoid cartridge valve 4, and the sixth solenoid cartridge valve 11 are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve 1, the sixth solenoid cartridge valve 11, and the seventh solenoid cartridge valve 12 are in a conducting state, the third solenoid cartridge valve 4 is in a pressure regulating state, the oil port B to the oil port A of the fourth solenoid cartridge valve 5 and the fifth solenoid cartridge valve 7 are in a conducting state, and the second solenoid cartridge valve 3 is in a cut-off state; the hydraulic oil from the oil source 205 enters from the oil port PS, because the sixth solenoid cartridge valve Valve 11 and first one-way cartridge valve 13 are in a one-way conduction state where port A is connected to port B and port B is not connected to port A, so the hydraulic oil enters the lower pressure side of ports A1 and A2 first after passing through the first electromagnetic cartridge valve 1. When the pressure on both sides is balanced, the hydraulic oil enters the rodless chamber of the side cylinder 201 and the working chamber of the main cylinder 202 from the sixth electromagnetic cartridge valve 11, the seventh electromagnetic cartridge valve 12 and the first one-way cartridge valve 13 respectively; the hydraulic oil discharged from the rod chamber of the side cylinder 201 enters the oil port BC, flows back to the hydraulic oil tank through the fifth electromagnetic cartridge valve 7, the fourth electromagnetic cartridge valve 5 and the third electromagnetic cartridge valve 4, and adjusts the rod chamber pressure of the side cylinder 201 through the third electromagnetic cartridge valve 4, thereby forming a supporting force; the pressing pressure is adjusted by the pilot proportional relief valve of the pressure regulating cartridge valve 9. The system hydraulic oil enters the rodless chamber of the side cylinder 201 and the working chamber of the main cylinder 202 at the same time, and the force increase speed of the slider 204 reaches the fastest.

[0030] d) Return stroke of the slider 204: the pilot solenoid valve of the second solenoid cartridge valve 3 is energized, and the pilot solenoid valves of the first solenoid cartridge valve 1, the third solenoid cartridge valve 4, the fourth solenoid cartridge valve 5, the fifth solenoid cartridge valve 7, the sixth solenoid cartridge valve 11, and the seventh solenoid cartridge valve 12 are de-energized; the oil port A to the oil port B of the second solenoid cartridge valve 3, the fourth solenoid cartridge valve 5, and the fifth solenoid cartridge valve 7 are in a conducting state, the first solenoid cartridge valve 1 and the third solenoid cartridge valve 4 are in a cut-off state, and the sixth solenoid cartridge valve 11 and the first one-way cartridge valve 13 are in a one-way cut-off state where the oil port B is not connected to the oil port A; the hydraulic oil from the oil source 205 enters from the oil port PS, passes through the second solenoid cartridge valve 3, the fourth solenoid cartridge valve 5, and the fifth solenoid cartridge valve 7, and enters the rod chamber of the side cylinder 201 from the oil port BC; the hydraulic oil discharged from the rodless chamber of the side cylinder 201 and the working chamber of the master cylinder 202 flows back to the hydraulic oil tank through the filling valve 203. The slide block 204 is lifted.

[0031] The multi-stage pressurization safety coupling hydraulic system of the liquid-filled forming hydraulic press of the present invention has multi-stage safety support and oil circuit safety coupling:

[0032] a) The fourth electromagnetic cartridge valve 5 and the fifth electromagnetic cartridge valve 7 form a multi-stage safety support for the rod chamber of the side cylinder 201. The hydraulic press slider 204 will lose the safety support only when both valves fail.

[0033] b) The fourth electromagnetic cartridge valve 5, the second non-return valve 6, the pressure regulating cartridge valve 9 and the third non-return valve 10 form a pressing safety coupling circuit. During the pressing process of the slider 204, the pressure regulating cartridge valve 9 can only build up pressure when the pilot electromagnetic valve of the fourth electromagnetic cartridge valve 5 is energized. The pressing safety coupling circuit avoids overpressure in the rod chamber and pipeline of the side cylinder 201 during pressing.

[0034] c) The first solenoid cartridge valve 1, the first non-return valve 2 and the third solenoid cartridge valve 4 form a return safety coupling circuit. During the return process of the slider 204, the oil outlet of the pilot relief valve of the third solenoid cartridge valve 4 is cut off, and the third solenoid cartridge valve 4 is in a reliable cut-off state. The return safety coupling circuit realizes the switching between the pressure of the rod chamber of the side cylinder 201 during the return and the supporting pressure during pressing, and reduces the risk of return stall due to valve failure.

[0035] d) The sixth solenoid valve 11, the first one-way valve 13, and the second one-way valve 14 form a pressure balance safety coupling circuit for the action chambers of the side cylinder 201 and the main cylinder 202 during pressurization and pressure relief. When the first-stage compression is switched to the second-stage compression, the sixth solenoid valve 11 and the first one-way valve 13 are in a one-way conduction state from the oil port A to the oil port B, and the hydraulic oil preferentially enters the side with lower pressure between the oil ports A1 and A2. At the same time, the hydraulic oil on the high-pressure side will not leak back to the low-pressure side. When the pressures on both sides are balanced, the hydraulic oil on the high-pressure side will not leak back to the low-pressure side. After balancing, the side cylinder 201 and the main cylinder 202 are pressed synchronously; when unloading pressure, the pilot solenoid valve of the sixth solenoid cartridge valve 11 is energized, the oil port B to the oil port A of the sixth solenoid cartridge valve 11 is connected, and the pilot proportional relief valve of the pressure regulating cartridge valve 9 adjusts the pressure relief pressure, and the hydraulic oil in the working chamber of the main cylinder 202 passes through the second one-way cartridge valve 14 and merges with the hydraulic oil in the rodless chamber of the side cylinder 201 for pressure relief, thereby achieving synchronous pressure relief and avoiding overpressure in the rodless chamber of the side cylinder 201, the working chamber of the main cylinder 202 and the pipeline caused by asynchronous pressure relief.

[0036] The multi-stage supercharging technology described above is not limited to two stages, and can be expanded to multiple stages.

Claims

1. The multi-stage pressurized safety coupling hydraulic system of the liquid filling forming hydraulic press is characterized by: The invention mainly comprises a first electromagnetic cartridge valve (1), a first non-return valve (2), a second electromagnetic cartridge valve (3), a third electromagnetic cartridge valve (4), a fourth electromagnetic cartridge valve (5), a second non-return valve (6), a fifth electromagnetic cartridge valve (7), a safety valve (8), a pressure regulating cartridge valve (9), a third non-return valve (10), a sixth electromagnetic cartridge valve (11), a seventh electromagnetic cartridge valve (12), a first non-return cartridge valve (13), a second non-return cartridge valve (14), a first pressure sensor (15), and a second pressure sensor (16); wherein the oil source inlet PS is connected to the first electromagnetic cartridge valve ( The A port of the first solenoid cartridge valve (1) is connected to the oil inlet of the first one-way valve (2) and the A port of the second solenoid cartridge valve (3); the oil outlet of the first one-way valve (2) is connected to the P port of the pilot solenoid valve of the first solenoid cartridge valve (1); the B port of the second solenoid cartridge valve (3) is connected to the A port of the third solenoid cartridge valve (4) and the A port of the fourth solenoid cartridge valve (5); the oil outlet of the pilot relief valve of the third solenoid cartridge valve (4) is connected to the A port of the pilot solenoid valve of the first solenoid cartridge valve (1); the B port of the fourth solenoid cartridge valve (5) is connected to the oil inlet of the second one-way valve (6) and the A port of the fifth solenoid cartridge valve (7); The oil outlet of the second check valve (6) is connected to the P port of the pilot solenoid valve of the fourth solenoid cartridge valve (5); the B port of the fifth solenoid cartridge valve (7) is connected to the oil inlet of the safety valve (8) and the return oil port BC of the hydraulic cylinder; the B port of the first solenoid cartridge valve (1) is connected to the A port of the pressure regulating cartridge valve (9), the A port of the sixth solenoid cartridge valve (11), and the A port of the seventh solenoid cartridge valve (12); the oil inlet of the third check valve (10) is connected to the X port of the pressure regulating cartridge valve (9); the oil outlet of the third check valve (10) is connected to the B port of the pilot solenoid valve of the fourth solenoid cartridge valve (5); The B port of the sixth solenoid cartridge valve (11) is connected to the B port of the second one-way cartridge valve (14), the detection port of the first pressure sensor (15), and the first-stage hydraulic cylinder pressure oil port A1; the B port of the seventh solenoid cartridge valve (12) is connected to the A port of the first one-way cartridge valve (13); the B port of the first one-way cartridge valve (13) is connected to the A port of the second one-way cartridge valve (14), the detection port of the second pressure sensor (16), and the second-stage hydraulic cylinder pressure oil port A2; the hydraulic oil tank is connected to the B port of the third solenoid cartridge valve (4), the oil outlet of the safety valve (8), and the B port of the pressure regulating cartridge valve (9).

2. The multi-stage pressurized safety coupling hydraulic system of the liquid-filled forming hydraulic press according to claim 1 is characterized in that: The hydraulic system settings for the hydraulic cylinder control mode are as follows: a) The slider moves downward quickly: the pilot solenoid valves of the first solenoid cartridge valve (1), the third solenoid cartridge valve (4), the fourth solenoid cartridge valve (5), and the fifth solenoid cartridge valve (7) are energized, and the pilot solenoid valves of the second solenoid cartridge valve (3), the sixth solenoid cartridge valve (11), and the seventh solenoid cartridge valve (12) are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve (1), the third solenoid cartridge valve (4), and the sixth solenoid cartridge valve (11) are in a conducting state, and the oil port B to the oil port A of the fourth solenoid cartridge valve (5) and the fifth solenoid cartridge valve (7) are in a conducting state. In the open state, the second solenoid cartridge valve (3) and the seventh solenoid cartridge valve (12) are in the closed state; the hydraulic oil from the oil source enters from the oil port PS, passes through the first solenoid cartridge valve (1) and the sixth solenoid cartridge valve (11), and enters the working chamber of the first-stage pressing hydraulic cylinder from the oil port A1, and the oil path entering the oil port A2 is closed; the hydraulic oil discharged from the working chamber of the return hydraulic cylinder enters the oil port BC, passes through the fifth solenoid cartridge valve (7), the fourth solenoid cartridge valve (5), and the third solenoid cartridge valve (4), and flows back to the hydraulic oil tank; the slide block is rapidly lowered by its own weight; b) Slider first-stage process: the pilot solenoid valves of the first solenoid cartridge valve (1), the fourth solenoid cartridge valve (5), and the fifth solenoid cartridge valve (7) are energized, and the pilot solenoid valves of the second solenoid cartridge valve (3), the third solenoid cartridge valve (4), the sixth solenoid cartridge valve (11), and the seventh solenoid cartridge valve (12) are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve (1) and the sixth solenoid cartridge valve (11) are in a conducting state, the third solenoid cartridge valve (4) is in a pressure regulating state, the oil port B to the oil port A of the fourth solenoid cartridge valve (5) and the fifth solenoid cartridge valve (7) are in a conducting state, and the second solenoid cartridge valve (3) and the seventh solenoid cartridge valve (12) are in a cut-off state; the oil source The hydraulic oil enters from the oil port PS, passes through the first electromagnetic cartridge valve (1) and the sixth electromagnetic cartridge valve (11), and enters the working chamber of the first-stage pressing hydraulic cylinder from the oil port A1, and the oil path entering the oil port A2 is cut off; the hydraulic oil discharged from the working chamber of the return hydraulic cylinder enters the oil port BC, passes through the fifth electromagnetic cartridge valve (7), the fourth electromagnetic cartridge valve (5), and the third electromagnetic cartridge valve (4) and flows back to the hydraulic oil tank, and the pressure of the working chamber of the return hydraulic cylinder is adjusted by the third electromagnetic cartridge valve (4), thereby forming a supporting force; the pressing pressure is adjusted by the pilot proportional relief valve of the pressure regulating cartridge valve (9); the full flow of the system hydraulic oil enters the working chamber of the first-stage pressing hydraulic cylinder, and the slide moves forward at the fastest speed; c) Slider two-stage operation: When the first pressure sensor (15) detects that the first-stage pressing pressure reaches the set value, the pilot solenoid valves of the first solenoid cartridge valve (1), the fourth solenoid cartridge valve (5), the fifth solenoid cartridge valve (7) and the seventh solenoid cartridge valve (12) are energized, and the pilot solenoid valves of the second solenoid cartridge valve (3), the third solenoid cartridge valve (4) and the sixth solenoid cartridge valve (11) are de-energized; the oil port A to the oil port B of the first solenoid cartridge valve (1), the sixth solenoid cartridge valve (11) and the seventh solenoid cartridge valve (12) are in a conducting state, the third solenoid cartridge valve (4) is in a pressure regulating state, the oil port B to the oil port A of the fourth solenoid cartridge valve (5) and the fifth solenoid cartridge valve (7) are in a conducting state, and the second solenoid cartridge valve (3) is in a cut-off state; the hydraulic oil from the oil source enters from the oil port PS, because the sixth solenoid cartridge valve (11) and the first one-way cartridge valve (13) are in a In the one-way conduction state where the oil port A is connected to the oil port B and the oil port B is not connected to the oil port A, the hydraulic oil passes through the first solenoid cartridge valve (1) and preferentially enters the side with lower pressure between the oil ports A1 and A2. When the pressures on both sides are balanced, the hydraulic oil simultaneously enters the action chambers of the first and second pressing hydraulic cylinders from the sixth solenoid cartridge valve (11), the seventh solenoid cartridge valve (12) and the first one-way cartridge valve (13). The hydraulic oil discharged from the action chamber of the return hydraulic cylinder enters the oil port BC, passes through the fifth solenoid cartridge valve (7), the fourth solenoid cartridge valve (5) and the third solenoid cartridge valve (4), and flows back to the hydraulic oil tank. The pressure of the action chamber of the return hydraulic cylinder is adjusted by the third solenoid cartridge valve (4), thereby forming a supporting force. The pressing pressure is adjusted by the pilot proportional relief valve of the pressure regulating cartridge valve (9). The system hydraulic oil simultaneously enters the action chambers of the first and second pressing hydraulic cylinders, and the force increasing speed of the slide reaches the fastest. d) Slider return stroke: the pilot solenoid valve of the second solenoid cartridge valve (3) is energized, and the pilot solenoid valves of the first solenoid cartridge valve (1), the third solenoid cartridge valve (4), the fourth solenoid cartridge valve (5), the fifth solenoid cartridge valve (7), the sixth solenoid cartridge valve (11), and the seventh solenoid cartridge valve (12) are de-energized; the oil port A to the oil port B of the second solenoid cartridge valve (3), the fourth solenoid cartridge valve (5), and the fifth solenoid cartridge valve (7) are in a conducting state, the first solenoid cartridge valve (1) and the third solenoid cartridge valve (4) are in a blocking state, and the sixth solenoid cartridge valve (11) and the first one-way cartridge valve (13) are in a one-way blocking state where the oil port B is not connected to the oil port A; the hydraulic oil from the oil source enters from the oil port PS, passes through the second solenoid cartridge valve (3), the fourth solenoid cartridge valve (5), and the fifth solenoid cartridge valve (7), and enters the working chamber of the return hydraulic cylinder from the oil port BC; the hydraulic oil discharged from the working chambers of the first and second pressing hydraulic cylinders flows back to the hydraulic oil tank through the filling valve; the slider is lifted.

3. The multi-stage pressurized safety coupling hydraulic system of a liquid-filled forming hydraulic press according to claim 1 or 2, characterized in that: The hydraulic system has multi-level safety support and oil circuit safety coupling: a) The fourth solenoid cartridge valve (5) and the fifth solenoid cartridge valve (7) form a multi-stage safety support for the return hydraulic cylinder action chamber. The hydraulic press slide will lose its safety support only when both valves fail; b) The fourth electromagnetic cartridge valve (5), the second non-return valve (6), the pressure regulating cartridge valve (9), and the third non-return valve (10) form a pressing safety coupling circuit. During the pressing process of the slider, the pressure regulating cartridge valve (9) can only build up pressure when the pilot electromagnetic valve of the fourth electromagnetic cartridge valve (5) is energized. The pressing safety coupling circuit avoids overpressure in the return action chamber and the pipeline during pressing; c) The first electromagnetic cartridge valve (1), the first non-return valve (2), and the third electromagnetic cartridge valve (4) form a return safety coupling circuit. During the return stroke of the slider, the oil outlet of the pilot relief valve of the third electromagnetic cartridge valve (4) is cut off, and the third electromagnetic cartridge valve (4) is in a reliable cut-off state. The return safety coupling circuit realizes the switching between the return pressure of the return action chamber and the support pressure during pressing, and reduces the risk of return stall due to valve failure; d) The sixth solenoid valve (11), the first non-return valve (13) and the second non-return valve (14) form a safety coupling circuit for balancing the pressure in the working chambers of the first and second pressure hydraulic cylinders during pressure increase and pressure relief. When the first pressure is switched to the second pressure, the sixth solenoid valve (11) and the first non-return valve (13) are in a one-way conduction state from the oil port A to the oil port B. The hydraulic oil preferentially enters the side with lower pressure between the oil ports A1 and A2. At the same time, the hydraulic oil on the high-pressure side will not leak back to the low-pressure side. When the two pressure ports are switched, the hydraulic oil on the high-pressure side will not leak back to the low-pressure side. After the side pressure is balanced, the first and second hydraulic cylinders are pressed synchronously; when unloading the pressure, the pilot solenoid valve of the sixth solenoid cartridge valve (11) is energized, the oil port B of the sixth solenoid cartridge valve (11) is connected to the oil port A, and the pilot proportional relief valve of the pressure regulating cartridge valve (9) adjusts the pressure relief pressure. The hydraulic oil in the working chamber of the second pressing hydraulic cylinder passes through the second one-way cartridge valve (14) and merges with the hydraulic oil in the working chamber of the first pressing hydraulic cylinder to unload the pressure, thereby achieving synchronous unloading and avoiding overpressure in the working chamber of the hydraulic cylinder and the pipeline caused by asynchronous unloading.

4. The multi-stage pressurized safety coupling hydraulic system of the liquid-filled forming hydraulic press according to claim 3 is characterized in that: The multi-stage supercharging is not limited to two stages, and can be extended to multiple stages.

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