A safety control system for a numerically controlled hydraulic cushion

Abstract

The present invention relates to the field of hydraulic control technology, and specifically discloses a safety control system for a numerically controlled hydraulic pad, including a hydraulic cylinder, a first oil supply circuit, a second oil supply circuit, a first oil return circuit, and a first valve assembly, a second valve assembly, and a third valve assembly. The first interface of the first valve assembly is connected to the first oil supply circuit through a pipeline, and the second interface of the first valve assembly is connected to the first interface of the second valve assembly through a pipeline; the second interface of the second valve assembly is connected to the rodless cavity through a pipeline; the rod cavity is connected to the first oil supply circuit through a pipeline; the first interface of the third valve assembly is connected to the second oil supply circuit through a pipeline, and the second interface of the third valve assembly is connected to the rod cavity through a pipeline. When the hydraulic cylinder pressurizes the mold, the present invention realizes the unloading of the control oil circuit and the oil supply circuit through the pipeline where the unloading valve assembly is located, ensures the safe operation of the system, and can also accelerate the extension speed of the piston, realizes the rapid pressurization of the mold by the hydraulic cylinder, and reduces the energy consumption of the system.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic control, and in particular to a safety control system for a numerically controlled hydraulic pad. Background Art

[0002] The CNC hydraulic cushion system is a key device on large presses. The system includes a complete hydraulic control system, which is mainly composed of hydraulic pumps, hydraulic cylinders, control valves, pipelines, and inductive monitoring devices. The actuators of the hydraulic cushion mainly include the upper crown and the hydraulic cylinder. The upper crown contacts the ejector rod, and the workpiece is clamped by the ejector rod. The hydraulic cylinder is arranged on the lower plane of the crown, providing the main power source for the hydraulic cushion, which can control the running speed of the crown and ensure its rapid positioning within the travel range.

[0003] The existing hydraulic pad only has a high-pressure servo valve in the rodless chamber. The rodless chamber needs to have a high energy to push the top crown to process the workpiece and achieve basic processing requirements. However, in modern industry, "energy saving" is a very important consideration. The design of the existing hydraulic pad needs to consider how to reduce energy consumption while meeting the processing requirements. In addition, when designing a CNC hydraulic pad system for the purpose of "energy saving", the connection of the pipeline and the design of the pipeline on-off control are bound to become complicated, so "safety" becomes the top priority of the design work.

[0004] Based on the above problems, how to achieve the energy-saving purpose of the hydraulic pad system on the basis of safety through numerical control is an issue that needs to be solved urgently. Summary of the invention

[0005] In view of the technical problems in the prior art, the present invention provides a safety control system for a numerically controlled hydraulic cushion.

[0006] A safety control system for a numerically controlled hydraulic cushion of the present invention comprises a hydraulic cylinder, a first oil supply circuit, a second oil supply circuit, a control oil circuit, a first oil return circuit, a second oil return circuit, a first valve assembly, a second valve assembly, a third valve assembly and a unloading valve assembly, wherein:

[0007] The interior of the hydraulic cylinder is divided into a rodless chamber and a rod chamber;

[0008] The first interface of the first valve assembly is connected to the first oil supply circuit through a pipeline, the second interface of the first valve assembly is connected to the first interface of the second valve assembly through a pipeline, and the third interface of the first valve assembly is connected to the first oil return circuit through a pipeline; when the hydraulic cylinder rises, the first interface and the second interface of the first valve assembly are connected, and when the hydraulic cylinder descends, the second interface and the third interface of the first valve assembly are connected;

[0009] The second interface of the second valve assembly is communicated with the rodless chamber through a pipeline;

[0010] The rod chamber is communicated with the first interface of the first valve assembly and the first oil supply path respectively through pipelines;

[0011] The first interface of the third valve assembly is communicated with the second oil supply circuit through a pipeline, the second interface of the third valve assembly is communicated with the rod chamber through a pipeline, and the second interface of the third valve assembly is also unidirectionally communicated with the first interface of the unloading valve assembly through a pipeline; the second interface of the unloading valve assembly is communicated with the first oil return circuit;

[0012] The control oil circuit is in communication with the first oil circuit control interfaces of the first valve assembly, the second valve assembly and the third valve assembly; the control oil circuit is also in communication with the first interface of the unloading valve assembly;

[0013] The second oil return circuit is in communication with the first valve assembly, the second valve assembly and the second oil circuit control interface of the third valve assembly.

[0014] Furthermore, the control oil circuit includes a main oil pipe and a first oil pipe, a second oil pipe, a third oil pipe, and a fourth oil pipe as branches of the main oil pipe; wherein:

[0015] The first oil pipe is in communication with the first oil circuit control interface of the first valve assembly; the third oil pipe is in communication with the first oil circuit control interface of the third valve assembly;

[0016] The second oil pipe is in communication with the fourth oil pipe and the first interface of the unloading valve assembly, and a first one-way valve is provided on the second oil pipe, and the flow direction of the first one-way valve is from the main oil pipe to the fourth oil pipe and the first interface of the unloading valve assembly;

[0017] The fourth oil pipe is in communication with the first oil circuit control interface of the second valve assembly and the first interface of the unloading valve assembly;

[0018] The second interface of the third valve assembly is unidirectionally connected to the fourth oil pipe through a pipeline.

[0019] Furthermore, the control oil circuit also includes a fifth oil pipe, which is connected to the rodless chamber via a pipeline provided with a second one-way valve, and the flow direction of the second one-way valve is from the rodless chamber to the fifth oil pipe; the fifth oil pipe is also connected to the first oil circuit control interface of the second valve assembly, and is connected to the fourth oil pipe via a pipeline provided with a third one-way valve; the flow direction of the third one-way valve is from the fourth oil pipe to the fifth oil pipe.

[0020] Furthermore, the second interface of the third valve assembly is connected to the fourth oil pipe through a pipeline provided with a fourth one-way valve, and the flow direction of the fourth one-way valve is from the second interface of the third valve assembly to the fourth oil pipe; the first oil supply circuit is connected to the first oil circuit control interface of the second valve assembly through the fourth one-way valve.

[0021] Furthermore, the safety control system also includes a fourth valve assembly, a first interface of the fourth valve assembly is connected to the rodless chamber through a pipeline, and a second interface of the fourth valve assembly is connected to the first oil return circuit through a pipeline.

[0022] Furthermore, the fourth valve assembly includes a first two-way valve, a first solenoid valve, a second solenoid valve, a first overflow valve, and a second overflow valve; wherein:

[0023] The first interface and the second interface of the first two-way valve are the first interface and the second interface of the fourth valve component;

[0024] The control chamber of the first two-way valve is connected to the first interface of the first solenoid valve, the first interface of the second solenoid valve and the first relief valve through a pipeline; the second interface of the second solenoid valve is connected to the second relief valve; the set pressure of the first relief valve is greater than the set pressure of the second relief valve;

[0025] The first oil circuit control interface of the second valve assembly is connected to the first interface of the first solenoid valve through a pipeline;

[0026] The second oil return path is communicated with the oil return interfaces of the first two-way valve, the first solenoid valve, the second solenoid valve, the first overflow valve, and the second overflow valve.

[0027] Furthermore, the safety control system further comprises a pressure detection assembly arranged on a pipeline connecting the rodless chamber and the first two-way valve, the pressure detection assembly comprising a first pressure sensor, a second pressure sensor and a third solenoid valve; wherein:

[0028] The first interface of the third solenoid valve is communicated with the rodless chamber, and the first pressure sensor is arranged on the second interface of the third solenoid valve;

[0029] The second pressure sensor is arranged on a pipeline connecting the rodless chamber and the first two-way valve;

[0030] The pressure measurement upper limit of the first pressure sensor is smaller than the pressure measurement upper limit of the second pressure sensor.

[0031] Furthermore, the safety control system also includes a third overflow valve, and a first interface and a second interface of the third overflow valve are respectively connected to the rodless chamber and the first oil return path through pipelines.

[0032] Further, the second valve assembly includes a second two-way valve, a third two-way valve, a fourth solenoid valve and a fifth solenoid valve, wherein:

[0033] The first interface of the second two-way valve is the first interface of the second valve assembly, the second interface of the second two-way valve is communicated with the first interface of the third two-way valve, and the second interface of the third two-way valve is the second interface of the second valve assembly;

[0034] The control chamber of the second two-way valve is connected to the fifth oil pipe through the fourth solenoid valve; the control chamber of the third two-way valve is connected to the fifth oil pipe through the fifth solenoid valve;

[0035] The fifth oil pipe is connected to the first oil circuit control interface of the fourth solenoid valve and the fifth solenoid valve;

[0036] The second oil return circuit is communicated with the second oil circuit control interfaces of the fourth solenoid valve and the fifth solenoid valve.

[0037] Furthermore, a fifth one-way valve is provided on the first oil supply line, and the flow direction of the fifth one-way valve is from the first oil supply line to the first valve assembly.

[0038] In the safety control system of the numerically controlled hydraulic pad of the present invention, the first interface of the first valve component is connected to the first oil supply circuit through a pipeline, the second interface of the first valve component is connected to the first interface of the second valve component through a pipeline, and the third interface of the first valve component is connected to the first oil return circuit through a pipeline; the second interface of the second valve component is connected to the rodless cavity through a pipeline; the rod cavity is connected to the first oil supply circuit and the first interface of the first valve component through a pipeline; the first interface of the third valve component is connected to the second oil supply circuit through a pipeline, the second interface of the third valve component is connected to the rod cavity through a pipeline, and the second interface of the third valve component is also connected to the first interface of the unloading valve component in one direction through the pipeline, and the second interface of the unloading valve component is connected to the first oil return circuit; the control oil circuit is connected to the first oil circuit control interface of the first valve component, the second valve component and the third valve component; the control oil circuit is also connected to the first interface of the unloading valve component; the second oil return circuit is connected to the second oil circuit control interface of the first valve component, the second valve component and the third valve component. The present invention realizes unloading of the control oil circuit and the oil supply circuit through the pipeline where the unloading valve assembly is located, thereby ensuring the safe operation of the system. It also controls the pressure in the rod chamber and the rodless chamber through the first valve assembly, the second valve assembly and the third valve assembly. Compared with the method of only arranging a high-pressure three-way valve in the rodless chamber in the prior art, it is more energy-efficient. This is because according to the calculation method that energy consumption is equal to the product of pressure and flow, when the flow is constant, reducing the pressure can reduce the energy consumption of the system. When the hydraulic cylinder pressurizes the mold, the hydraulic oil in the rod chamber is discharged and merged with the hydraulic oil transported by the rodless chamber, and flows to the rodless chamber together, thereby accelerating the extension speed of the piston, and realizing the rapid pressurization of the mold by the hydraulic cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 A module composition diagram of a safety control system for a numerically controlled hydraulic cushion according to an embodiment of the present invention;

[0041] Figure 2 Another module composition diagram of a safety control system for a numerically controlled hydraulic cushion according to an embodiment of the present invention;

[0042] Figure 3 A structural diagram of a safety control system for a numerically controlled hydraulic cushion according to an embodiment of the present invention;

[0043] Among them, 10-hydraulic cylinder, 101-rodless chamber, 102-rod chamber, 103-mold, 104-piston, 105-displacement sensor, 20-first valve assembly, 30-second valve assembly, 301-second two-way valve, 302-third two-way valve, 303-fourth solenoid valve, 304-fifth solenoid valve, 40-third valve assembly, 50-unloading valve assembly, 60-fourth valve assembly, 601-first two-way valve, 602-first solenoid valve, 603-second solenoid valve, 604-first overflow valve, 605-second overflow valve, 70-pressure detection assembly, 701-first pressure sensor, 702-second pressure sensor, 703-third solenoid valve, 80-third overflow valve, 90-first one-way valve, 100-second one-way valve, 110-third one-way valve, 120-fourth one-way valve, 130-fifth one-way valve. DETAILED DESCRIPTION

[0044] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0045] A safety control system for a numerically controlled hydraulic cushion according to an embodiment of the present invention, such as Figure 1 and Figure 3 As shown, the safety control system includes a hydraulic cylinder 10, a first oil supply circuit P1, a second oil supply circuit P2, a control oil circuit X, a first oil return circuit T, a second oil return circuit Y, a first valve assembly 20, a second valve assembly 30, a third valve assembly 40 and an unloading valve assembly 50, wherein:

[0046] The interior of the hydraulic cylinder 10 is divided into a rodless chamber 101 and a rod chamber 102; Figure 1 As shown, the top of the hydraulic cylinder 10 is a mold 103 to be processed. The safety control system of the CNC hydraulic pad in the embodiment of the present invention is to realize that the piston 104 in the hydraulic cylinder 10 can move upward and downward and operate safely. When the piston 104 moves upward, hydraulic oil enters the rodless chamber 101 and then flows out from the rod chamber 102. When the piston 104 moves downward, hydraulic oil enters the rod chamber 102 and then flows out from the rodless chamber 101. In order to more accurately grasp the rising and falling distances of the piston 104, a displacement sensor 105 can be set inside the hydraulic cylinder 10 in this embodiment. Figure 1 As shown, in the embodiment of the present invention, the interfaces for connecting the rodless cavity 101 and the rod cavity 102 with the external pipeline are represented by A and B respectively.

[0047] In this embodiment, the first interface of the first valve assembly 20 is connected to the first oil supply circuit P1 through a pipeline, the second interface of the first valve assembly 20 is connected to the first interface of the second valve assembly 30 through a pipeline, and the third interface of the first valve assembly 20 is connected to the first oil return circuit T through a pipeline; when the hydraulic cylinder 10 rises, the first interface and the second interface of the first valve assembly 20 are connected, and the hydraulic oil flows from the first interface of the first valve assembly 20 to the second interface; when the hydraulic cylinder 10 descends, the second interface and the third interface of the first valve assembly 20 are connected, and the hydraulic oil flows from the second interface of the first valve assembly 20 to the third interface. The second interface of the second valve assembly 30 is connected to the rodless chamber 101 through a pipeline, that is, it is connected to the A interface; the rod chamber 102 is connected to the first oil supply circuit P1 through a pipeline, that is, the B interface is connected to the first oil supply circuit P1, and the rod chamber 102 is also connected to the first interface of the first valve assembly 20 through a pipeline.

[0048] The first interface of the third valve assembly 40 is connected to the second oil supply circuit P2 through a pipeline, the second interface of the third valve assembly 40 is connected to the rod chamber 102 through a pipeline, the second interface of the third valve assembly 40 is also connected to the first interface of the unloading valve assembly 50 through a pipeline, and the second interface of the unloading valve assembly 50 is connected to the first oil return circuit T; Figure 1 As shown, the second interface of the third valve assembly 40 is connected to the B interface through a pipeline. In the embodiment of the present invention, when the first interface and the second interface of the third valve assembly 40 are connected, the hydraulic oil in the second oil supply circuit P2 enters from the first interface of the third valve assembly 40, flows out from the second interface, and flows to the B interface of the rod chamber 102. When the first interface and the second interface of the third valve assembly 40 are not connected, the oil pressure in the pipeline at the second interface can flow into the first oil return circuit T through the unloading valve assembly 50 to achieve unloading, which plays a safety role.

[0049] The control oil circuit X is communicated with the first oil circuit control interfaces of the first valve assembly 20, the second valve assembly 30 and the third valve assembly 40, and the control oil circuit X is also communicated with the first interface of the unloading valve assembly 50; the second return oil circuit Y is communicated with the second oil circuit control interfaces of the first valve assembly 20, the second valve assembly 30 and the third valve assembly 40. The setting of the control oil circuit X and the second return oil circuit Y is to control the working states of the first valve assembly 20, the second valve assembly 30 and the third valve assembly 40 through the oil circuit, and the oil is input from the control oil circuit X to the first oil circuit control interface, and output from the second oil circuit control interface to flow back to the second return oil circuit Y.

[0050] In addition, the control oil circuit X is also connected to the first interface of the unloading valve assembly 50, and the hydraulic oil in the control oil circuit X can also flow into the first return oil circuit T through the unloading valve assembly 50 to achieve unloading, thereby ensuring the reliability and safety of system control.

[0051] like Figure 1 As shown, in the embodiment of the present invention, the interfaces of each valve component are represented by 1, 2, and 3 to represent the first interface, the second interface, and the third interface. Figure 1 , the working principle of the embodiment of the present invention is as follows:

[0052] When the hydraulic cylinder 10 rises: the first oil supply circuit P1 supplies oil, and the hydraulic oil therein flows into the first interface 1 of the first valve assembly 20. At this time, the first interface 1 and the second interface 2 of the first valve assembly 20 are connected, and the hydraulic oil flows into the first interface 1 of the second valve assembly 30, and flows out from the second interface 2 of the second valve assembly 30, and flows into the rodless chamber 101 through the A interface; the hydraulic oil is discharged from the B interface of the rod chamber 102, and the third valve assembly 40 is closed. The oil discharged from the B interface returns to the first interface 1 of the first valve assembly 20 through the pipeline again, forming a differential circuit, that is, the hydraulic oil in the rod chamber 102 is discharged and merged with the hydraulic oil transported to the rodless chamber 101 by the first oil supply circuit P1, and flows to the rodless chamber 101 together, which can accelerate the extension speed of the piston 104 and realize the rapid pressurization of the mold by the hydraulic cylinder.

[0053] When the hydraulic cylinder 10 descends: the piston 104 of the hydraulic cylinder 10 is subjected to the downward pressure (external force) F, or due to the deadweight of the piston 104, the piston 104 will move downward, at this time, the second oil supply circuit P2 supplies oil, and the hydraulic oil enters the first interface 1 of the third valve assembly 40. At this time, the first interface 1 and the second interface 2 of the third valve assembly 40 are connected, and the hydraulic oil flows to the B interface of the rod chamber 102 through the first interface 1 and the second interface 2 of the third valve assembly 40. The piston 104 is subjected to the external force and the pressure of the rod chamber 102, and has a tendency to move downward; the hydraulic oil is discharged from the A interface of the rodless chamber 101, enters the second interface 2 of the second valve assembly 30, and then flows out through the first interface 1 of the second valve assembly 30. In this mode, the second interface 2 and the third interface 3 of the first valve assembly 20 are connected, so the hydraulic oil flows to the first return oil circuit T through the second interface 2 and the third interface 3 of the first valve assembly 20. In this process, the pressure of the hydraulic oil in the rodless chamber 101 can be controlled to be maintained within the target pressure by controlling the opening sizes of the second interface 2 and the third interface 3 in the first valve assembly 20 .

[0054] like Figure 1 As shown, the first oil supply line P1 and the second oil supply line P2 in the embodiment of the present invention can actually supply oil to the rod chamber 102, so preferably, the second oil supply line P2 is used as a high-pressure oil supply, so that when the hydraulic cylinder 10 needs to descend, the second oil supply line P2 can first quickly pass oil to allow the piston 104 to quickly descend, and then the second oil supply line P2 is closed, and the first oil supply line P1 is used to supply oil to slow down the descending speed of the piston 104. The selection of specific oil lines and the timing of replacement are determined by those skilled in the art according to the implementation situation, and the embodiment of the present invention does not limit it.

[0055] Since the second interface 2 of the third valve assembly 40 is connected to the first interface 1 of the unloading valve assembly 50 through a pipeline in one direction in the embodiment of the present invention, when the hydraulic cylinder 10 needs to unload when it is in the ascending, descending, or stopping state, the unloading valve assembly 50 can be controlled to be in an open state, and the hydraulic oil in the first oil supply circuit P1 and the second oil supply circuit P2 can flow from the unloading valve assembly 50 to the first oil return circuit T to realize the unloading of the oil supply circuit. If unloading is not required, the oil pressure in the pipeline can be maintained by controlling the unloading valve assembly 50 to be in a closed state. In this embodiment, the third valve assembly 40 is a two-way valve provided with a first interface and a second interface. Compared with a three-way valve, a two-way valve is easier to control and more reliable to control, which further improves the safety and practicality of the system of this embodiment.

[0056] Specifically, Figure 2 and Figure 3 As shown, the control oil circuit X includes a main oil pipe and a first oil pipe, a second oil pipe, a third oil pipe, and a fourth oil pipe as branches of the main oil pipe; wherein: the first oil pipe is connected to the first oil circuit control interface of the first valve assembly 20; the third oil pipe is connected to the first oil circuit control interface of the third valve assembly 40; the second oil pipe is connected to the fourth oil pipe and the first interface of the unloading valve assembly 50, and the second oil pipe is provided with a first one-way valve 90, and the flow direction of the first one-way valve 90 is from the main oil pipe to the fourth oil pipe and the first interface of the unloading valve assembly 50; the fourth oil pipe is connected to the first oil circuit control interface of the second valve assembly 30 and the first interface 1 of the unloading valve assembly 50; the second interface of the third valve assembly 40 is connected to the fourth oil pipe in one direction through a pipeline.

[0057] In this embodiment, the first one-way valve 90 can ensure that the oil in the main oil pipe flows unidirectionally to the second valve assembly 30 , thereby controlling the working state of the second valve assembly 30 .

[0058] Preferably, the control oil circuit also includes a fifth oil pipe, which is connected to the rodless chamber 101 through a pipeline provided with a second one-way valve 100, and the flow direction of the second one-way valve 100 is from the rodless chamber 101 to the fifth oil pipe. The fifth oil pipe is also connected to the first oil circuit control interface of the second valve assembly 30, and is connected to the fourth oil pipe through a pipeline provided with a third one-way valve 110; the flow direction of the third one-way valve 110 is from the fourth oil pipe to the fifth oil pipe. If the control oil circuit X fails and the working state of the second valve assembly 30 cannot be controlled, the control oil can be obtained through the rodless chamber 101, and the oil flows from the A interface to the second valve assembly 30 through the second one-way valve 100. In order to prevent the control oil of the second valve assembly 30 from being unloaded, the third one-way valve 110 is added, and the control oil can only flow from the fourth oil pipe to the fifth oil pipe, but cannot flow from the fifth oil pipe to the fourth oil pipe.

[0059] More preferably, the second interface of the third valve assembly 40 is connected to the fourth oil pipe through a pipeline provided with a fourth one-way valve 120, and the flow direction of the fourth one-way valve 120 is from the second interface of the third valve assembly 40 to the fourth oil pipe; the first oil supply path P1 is connected to the first oil circuit control interface of the second valve assembly 30 through the fourth one-way valve 120. If the control oil circuit X fails and the working state of the second valve assembly 30 cannot be controlled, oil can be supplied through the first oil supply path P1, and the oil in the first oil supply path P1 flows through the fourth one-way valve 20 and then flows to the second valve assembly 30, thereby realizing the on-off control of the second valve assembly 30.

[0060] The design of the unloading valve assembly 50 and the related pipelines in the embodiment of the present invention can unload the oil at the oil outflow ends of the first one-way valve 90 and the fourth one-way valve 120 to prevent the pipeline oil pressure from being too high.

[0061] Specifically, based on the above embodiments, Figure 2 and 3 As shown, the safety control system of the embodiment of the present invention further includes a fourth valve assembly 60, the first interface 1 of the fourth valve assembly 60 is connected to the A interface of the rodless chamber 101 through a pipeline, and the second interface 2 of the fourth valve assembly 60 is connected to the first oil return circuit T through a pipeline. The fourth valve assembly 60 of the embodiment of the present invention is to control the sealing and discharge of the oil in the rodless chamber 101, the sealing is the pressure building state, and the discharge is the unloading state.

[0062] Specifically, Figure 3 As shown, the fourth valve assembly 60 of the embodiment of the present invention includes a first two-way valve 601, a first solenoid valve 602, a second solenoid valve 603, a first relief valve 604, and a second relief valve 605; wherein: the first interface and the second interface of the first two-way valve 601 are the first interface and the second interface of the fourth valve assembly 60, that is, the first interface of the first two-way valve 601 is connected to the A interface of the rodless chamber 101 through a pipeline, and the second interface of the first two-way valve 601 is connected to the first oil return circuit T through a pipeline; the control chamber of the first two-way valve 601 is connected to the first interface of the first solenoid valve 602 and the second solenoid valve 603 through a pipeline. The first interface is connected to the first overflow valve 604; the second interface of the second solenoid valve 603 is connected to the second overflow valve 605; the set pressure of the first overflow valve 604 is greater than the set pressure of the second overflow valve 605, that is, relatively speaking, in this embodiment, the first overflow valve 604 is a high-pressure overflow valve, and the second overflow valve is a low-pressure overflow valve; the first oil circuit control interface of the second valve assembly 30 is connected to the first interface of the first solenoid valve 602 through a pipeline; the second return oil circuit Y is connected to the return oil interfaces of the first two-way valve 601, the first solenoid valve 602, the second solenoid valve 603 and the first overflow valve 604, and the second overflow valve 605.

[0063] In this embodiment, the first two-way valve 601 can be a two-way cartridge valve. When the first solenoid valve 602 is not energized, the rodless chamber 101 is unloaded, and the oil flows into the first interface of the first two-way valve 601 and is discharged to the return oil circuit T through the second interface; when the first solenoid valve 602 is energized and the second solenoid valve 603 is energized, if the pressure of the rodless chamber 101 exceeds the pressure set by the low-pressure relief valve, the first two-way valve 601 opens to unload, so that the pressure of the rodless chamber 101 is not higher than the set pressure of the low-pressure relief valve; when the first solenoid valve 602 is energized and the second solenoid valve 603 is not energized, if the pressure of the rodless chamber 101 exceeds the pressure set by the high-pressure relief valve, the first two-way valve 601 opens to unload, so that the pressure of the rodless chamber 101 is not higher than the set pressure of the high-pressure relief valve, thereby realizing multi-stage pressure protection and keeping the pressure of the rodless chamber 101 within a controllable range. In addition, the first oil circuit control interface of the second valve assembly 30 is connected to the first interface of the first solenoid valve 602 through a pipeline. When the oil pressure of the first oil circuit control interface of the second valve assembly 30 is too high, it flows out to the second oil return circuit Y through the return oil interface of the first solenoid valve 602 to achieve unloading.

[0064] Specifically, Figure 3 As shown, the safety control system of the embodiment of the present invention also includes a pressure detection component 70 arranged on the pipeline connecting the rodless chamber 101 and the first two-way valve 601, and the pressure detection component 70 includes a first pressure sensor 701, a second pressure sensor 702 and a third solenoid valve 703; wherein: the first interface of the third solenoid valve 703 is connected to the rodless chamber 101, and the first pressure sensor 701 is arranged on the second interface of the third solenoid valve 703; the second pressure sensor 702 is arranged on the pipeline connecting the rodless chamber 101 and the first two-way valve 601; the pressure measurement upper limit of the first pressure sensor 701 is less than the measurement upper limit of the second pressure sensor 702. In this embodiment, two pressure sensors with different ranges are arranged on the oil circuit of the rodless chamber 101, which helps to improve the control accuracy. In addition, when the pressure in the rodless chamber 101 is low, the low-pressure pressure sensor (i.e., the first pressure sensor 701) is used to measure the pressure. At this time, the third solenoid valve 703 is connected, and the oil can flow from the rodless chamber 101 into the third solenoid valve 703; when the pressure in the rodless chamber 101 is high, the high-pressure pressure sensor (i.e., the second pressure sensor 702) is used. At this time, the third solenoid valve 703 is disconnected. The third solenoid valve 703 is used to close the oil circuit when the pressure is high to prevent the high-pressure oil from impacting the low-pressure pressure sensor and causing damage to the low-pressure pressure sensor.

[0065] Specifically, Figure 2As shown, the safety control system further includes a third relief valve 80, and the first interface and the second interface of the third relief valve 80 are respectively connected to the rodless chamber 101 and the first oil return circuit T through pipelines. The third relief valve 80 in this embodiment can use a straight-through relief valve. When the pressure in the rodless chamber 101 is too high, the oil can flow to the first oil return circuit T through the third relief valve 80 to achieve pressure relief and protect the safe and stable operation of the entire system.

[0066] Specifically, Figure 3 As shown, the second valve assembly 30 of the embodiment of the present invention includes a second two-way valve 301, a third two-way valve 302, a fourth solenoid valve 303 and a fifth solenoid valve 304, wherein: the first interface of the second two-way valve 301 is the first interface of the second valve assembly 30, that is, the first interface of the second two-way valve 301 is connected to the second interface of the first valve assembly 20; the second interface of the second two-way valve 301 is connected to the first interface of the third two-way valve 302, and the second interface of the third two-way valve 302 is the second interface of the second valve assembly 30, that is, the second interface of the third two-way valve 302 is connected to the A interface of the rodless chamber 101; the control chamber of the second two-way valve 301 is connected to the fifth oil pipe through the fourth solenoid valve 303; the control chamber of the third two-way valve 302 is connected to the fifth oil pipe through the fifth solenoid valve 304; the fifth oil pipe is connected to the first oil circuit control interface of the fourth solenoid valve 303 and the fifth solenoid valve 304; the second oil return circuit Y is connected to the second oil circuit control interface of the fourth solenoid valve 303 and the fifth solenoid valve 304.

[0067] The second two-way valve 301 and the third two-way valve 302 in the embodiment of the present invention control their switch states by controlling the oil circuit X. Therefore, when an unexpected situation occurs during the operation of the system oil circuit and the operation needs to be stopped urgently, the cut-off function control of the second valve assembly 30 can be achieved by controlling the oil pressure in the fifth oil pipe, thereby cutting off the pipeline between the rodless chamber 101 and the first valve assembly 20, and locking the hydraulic cylinder 10 in the current position. In addition, the present invention can achieve the above functions by using one two-way valve and one solenoid valve. When two two-way valves, the second two-way valve 301 and the third two-way valve 302, and two solenoid valves, the fourth solenoid valve 303 and the fifth solenoid valve 304, are used, the margin can be increased, and the operation effect of the system can be further improved.

[0068] Specifically, Figure 3 As shown, in the embodiment of the present invention, a fifth one-way valve 130 is provided on the first oil supply line P1, and the flow direction of the fifth one-way valve 130 is from the first oil supply line P1 to the first valve assembly 20. The fifth one-way valve 130 is provided at the outlet end of the first oil supply line P1 to prevent the oil in the pipeline connected thereto from flowing back to the first oil supply line P1 when the oil pressure is high, so as to ensure the stable operation of the system.

[0069] The first valve assembly 20 of the embodiment of the present invention can adopt a three-way servo valve that can realize the function of the embodiment of the present invention, the third valve assembly 40 and the unloading valve assembly 40 can adopt a two-way valve, and the present invention does not limit the specific product model. In addition, the cartridge valves of the embodiment of the present invention can all be implemented by a two-way cartridge valve, and the present invention does not limit the specific product model, and technical personnel in this field can choose it at their own discretion.

[0070] In addition, the first oil supply circuit P1, the second oil supply circuit P2 and the control oil circuit X in the embodiment of the present invention are all pipelines for outputting hydraulic oil to the outside, so they are all connected to the accumulator to achieve the required oil pressure in the pipeline.

[0071] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A safety control system for a CNC hydraulic cushion, characterized in that: The safety control system comprises a hydraulic cylinder, a first oil supply circuit, a second oil supply circuit, a control oil circuit, a first oil return circuit, a second oil return circuit, a first valve assembly, a second valve assembly, a third valve assembly and a load relief valve assembly, wherein: The interior of the hydraulic cylinder is divided into a rodless chamber and a rod chamber; The first interface of the first valve assembly is connected to the first oil supply circuit through a pipeline, the second interface of the first valve assembly is connected to the first interface of the second valve assembly through a pipeline, and the third interface of the first valve assembly is connected to the first oil return circuit through a pipeline; when the hydraulic cylinder rises, the first interface and the second interface of the first valve assembly are connected, and when the hydraulic cylinder descends, the second interface and the third interface of the first valve assembly are connected; The second interface of the second valve assembly is communicated with the rodless chamber through a pipeline; The rod chamber is communicated with the first interface of the first valve assembly and the first oil supply path respectively through pipelines; The first interface of the third valve assembly is communicated with the second oil supply circuit through a pipeline, the second interface of the third valve assembly is communicated with the rod chamber through a pipeline, and the second interface of the third valve assembly is also unidirectionally communicated with the first interface of the unloading valve assembly through a pipeline; the second interface of the unloading valve assembly is communicated with the first oil return circuit; The control oil circuit is in communication with the first oil circuit control interfaces of the first valve assembly, the second valve assembly and the third valve assembly; the control oil circuit is also in communication with the first interface of the unloading valve assembly; The second oil return circuit is in communication with the first valve assembly, the second valve assembly and the second oil circuit control interface of the third valve assembly.

2. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 1, characterized in that: The control oil circuit includes a main oil pipe and a first oil pipe, a second oil pipe, a third oil pipe, and a fourth oil pipe as branches of the main oil pipe; wherein: The first oil pipe is in communication with the first oil circuit control interface of the first valve assembly; the third oil pipe is in communication with the first oil circuit control interface of the third valve assembly; The second oil pipe is in communication with the fourth oil pipe and the first interface of the unloading valve assembly, and a first one-way valve is provided on the second oil pipe, and the flow direction of the first one-way valve is from the main oil pipe to the fourth oil pipe and the first interface of the unloading valve assembly; The fourth oil pipe is in communication with the first oil circuit control interface of the second valve assembly and the first interface of the unloading valve assembly; The second interface of the third valve assembly is unidirectionally connected to the fourth oil pipe through a pipeline.

3. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 2, characterized in that: The control oil circuit also includes a fifth oil pipe, which is connected to the rodless chamber via a pipeline provided with a second one-way valve, and the flow direction of the second one-way valve is from the rodless chamber to the fifth oil pipe; the fifth oil pipe is also connected to the first oil circuit control interface of the second valve assembly, and is connected to the fourth oil pipe via a pipeline provided with a third one-way valve; the flow direction of the third one-way valve is from the fourth oil pipe to the fifth oil pipe.

4. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 3, characterized in that: The second interface of the third valve assembly is connected to the fourth oil pipe through a pipeline provided with a fourth one-way valve, and the flow direction of the fourth one-way valve is from the second interface of the third valve assembly to the fourth oil pipe; the first oil supply circuit is connected to the first oil circuit control interface of the second valve assembly through the fourth one-way valve and the fourth oil pipe.

5. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 1, characterized in that: The safety control system further comprises a fourth valve assembly, a first interface of the fourth valve assembly is communicated with the rodless chamber via a pipeline, and a second interface of the fourth valve assembly is communicated with the first oil return path via a pipeline.

6. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 5, characterized in that: The fourth valve assembly includes a first two-way valve, a first solenoid valve, a second solenoid valve, a first overflow valve, and a second overflow valve; wherein: The first interface and the second interface of the first two-way valve are the first interface and the second interface of the fourth valve component; The control chamber of the first two-way valve is connected to the first interface of the first solenoid valve, the first interface of the second solenoid valve and the first relief valve through a pipeline; the second interface of the second solenoid valve is connected to the second relief valve; the set pressure of the first relief valve is greater than the set pressure of the second relief valve; The first oil circuit control interface of the second valve assembly is connected to the first interface of the first solenoid valve through a pipeline; The second oil return path is communicated with the oil return interfaces of the first two-way valve, the first solenoid valve, the second solenoid valve, the first overflow valve, and the second overflow valve.

7. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 6, characterized in that: The safety control system further includes a pressure detection assembly disposed on a pipeline connecting the rodless chamber and the first two-way valve, the pressure detection assembly including a first pressure sensor, a second pressure sensor and a third solenoid valve; wherein: The first interface of the third solenoid valve is communicated with the rodless chamber, and the first pressure sensor is arranged on the second interface of the third solenoid valve; The second pressure sensor is arranged on a pipeline connecting the rodless chamber and the first two-way valve; The pressure measurement upper limit of the first pressure sensor is smaller than the pressure measurement upper limit of the second pressure sensor.

8. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 4, characterized in that: The safety control system further comprises a third overflow valve, a first interface and a second interface of the third overflow valve are respectively connected with the rodless chamber and the first oil return path through pipelines.

9. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 4, characterized in that: The second valve assembly includes a second two-way valve, a third two-way valve, a fourth solenoid valve and a fifth solenoid valve, wherein: The first interface of the second two-way valve is the first interface of the second valve assembly, the second interface of the second two-way valve is communicated with the first interface of the third two-way valve, and the second interface of the third two-way valve is the second interface of the second valve assembly; The control chamber of the second two-way valve is connected to the fifth oil pipe through the fourth solenoid valve; the control chamber of the third two-way valve is connected to the fifth oil pipe through the fifth solenoid valve; The fifth oil pipe is connected to the first oil circuit control interface of the fourth solenoid valve and the fifth solenoid valve; The second oil return circuit is communicated with the second oil circuit control interfaces of the fourth solenoid valve and the fifth solenoid valve.

10. A safety control system for a numerically controlled hydraulic cushion as claimed in claim 4, characterized in that: A fifth one-way valve is provided on the first oil supply line, and the flow direction of the fifth one-way valve is from the first oil supply line to the first valve assembly.

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