Hydraulic differential circuit integrated system and cylinder driving method

Abstract

The application discloses a hydraulic differential circuit integrated system and a cylinder driving method, and relates to the technical field of hydraulic differential control; the system comprises a circuit body, four cartridge valves and two pilot reversing valves; each cartridge valve is provided with a first main oil port, a second main oil port and a pilot port, each pilot reversing valve is provided with two pilot working oil ports and is in communication with the pilot ports of different cartridge valves; the first main oil port of the first cartridge valve is in communication with a cylinder rod cavity, and the second main oil port is in communication with the second main oil port of the third cartridge valve; the first main oil port of the third cartridge valve is in communication with a plug cavity; the second main oil ports of the second cartridge valve and the fourth cartridge valve are in communication with a total oil return port; the total oil inlet is in communication with the second main oil port of the first cartridge valve and the second main oil port of the third cartridge valve; the application realizes the cooperative control of multiple cartridge valves by using fewer pilot control elements, realizes the differential speed-up of the cylinder, reduces the manufacturing cost, and improves the integration and stability.

Description

Technical Field

[0001] This invention relates to the field of hydraulic differential control system technology, and in particular to a hydraulic differential circuit integrated system and a cylinder driving method. Background Technology

[0002] In existing hydraulic systems, basic cylinder movement control typically uses two-way cartridge valves as the main valve to achieve high-flow on / off switching. In current technology, each two-way cartridge valve requires a separate pilot valve for control, with the opening and closing of the cartridge valve controlled by the establishment and release of pilot oil pressure. When the hydraulic system needs to achieve multiple working states of the cylinder (such as stationary, forward, and retracted), multiple cartridge valves and a corresponding number of pilot valves are often required, resulting in a large number of system components, high manufacturing costs, complex piping connections, low overall system integration, and a large size. Furthermore, the control logic of multiple independent pilot valves needs to be debugged and matched separately, leading to long system debugging cycles and difficulty in guaranteeing operational stability. For cylinder control circuits requiring differential speed-up functions, existing technologies typically require additional control valves and piping, further increasing system complexity and cost. Summary of the Invention

[0003] The purpose of this invention is to provide a hydraulic differential circuit integrated system and a cylinder driving method to solve the problems existing in the prior art. It can achieve coordinated control of multiple cartridge valves with fewer pilot control elements, reduce manufacturing costs, and improve system integration and operational stability while realizing the differential speed-up function of the cylinder.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention provides a hydraulic differential circuit integrated system, comprising: The circuit body is equipped with a main oil inlet and a main oil return port; Four cartridge valves are installed on the circuit body, and each cartridge valve is provided with a first main oil port, a second main oil port and a pilot port; Two pilot directional valves are installed on the circuit body. Each pilot directional valve is provided with a pilot inlet, a pilot return port, a first pilot working port, and a second pilot working port. The cylinder is provided with a plug chamber and a rod chamber; the first main oil port of the first cartridge valve is connected to the rod chamber, and the second main oil port is connected to the second main oil port of the third cartridge valve; the first main oil port of the third cartridge valve is connected to the plug chamber; the first main oil port of the second cartridge valve is connected to the rod chamber, and the second main oil port is connected to the total return oil port; the first main oil port of the fourth cartridge valve is connected to the plug chamber, and the second main oil port is connected to the total return oil port. The main oil inlet is connected to both the second main oil inlet of the first cartridge valve and the second main oil inlet of the third cartridge valve; The pilot inlet ports of the first and second pilot directional valves are both connected to the main inlet port via pilot control oil circuits. The pilot return ports of the first and second pilot directional valves are both connected to the main return port. The first pilot working port of the first pilot directional valve is connected to the pilot port of the first cartridge valve, and the second pilot working port of the first pilot directional valve is connected to the pilot port of the second cartridge valve. The first pilot working port of the second pilot directional valve is connected to the pilot port of the third cartridge valve, and the second pilot working port of the second pilot directional valve is connected to the pilot port of the fourth cartridge valve.

[0005] Optionally, each of the cartridge valves is a two-way cartridge valve.

[0006] Optionally, each of the pilot directional valves is a two-position four-way solenoid directional valve; the first pilot directional valve is a first two-position four-way solenoid directional valve, and the second pilot directional valve is a second two-position four-way solenoid directional valve. The first pilot working port of the first and second position four-way solenoid directional valve is port A, the second pilot working port is port B, the pilot inlet port is port P, and the pilot return port is port T. The first pilot working port of the second two-position four-way solenoid directional valve is port A, the second pilot working port is port B, the pilot inlet port is port P, and the pilot return port is port T. The A port of the first two-position four-way solenoid directional valve is connected to the pilot port of the first cartridge valve, and the B port is connected to the pilot port of the second cartridge valve. The A port of the second two-position four-way solenoid directional valve is connected to the pilot port of the third cartridge valve, and the B port is connected to the pilot port of the fourth cartridge valve.

[0007] Optionally, it also includes a first check valve, which is located in the pilot control oil circuit and is used to allow the oil from the main inlet to flow unidirectionally into the P port of the first two-position four-way solenoid directional valve and the P port of the second two-position four-way solenoid directional valve.

[0008] Optionally, a second check valve and a third check valve may also be included; The second check valve is connected in the control oil circuit between port A of the first two-position four-way solenoid valve and port B of the second two-position four-way solenoid valve, and is used to allow oil to flow unidirectionally from port A of the first two-position four-way solenoid valve to port B of the second two-position four-way solenoid valve. The third check valve is connected in the control oil circuit between port A of the second two-position four-way solenoid valve and port B of the first two-position four-way solenoid valve, and is used to allow oil to flow unidirectionally from port A of the second two-position four-way solenoid valve to port B of the first two-position four-way solenoid valve.

[0009] Optionally, a first pressure gauge is also included, which is located in the oil line between the rod chamber of the cylinder and the first cartridge valve, for monitoring the pressure in the rod chamber.

[0010] Optionally, a second pressure gauge is also included, which is located in the oil line between the plug chamber of the cylinder and the third cartridge valve, for monitoring the pressure in the plug chamber.

[0011] Optionally, the pilot control branch between each of the pilot ports and the corresponding A port or B port is integrated inside the loop body.

[0012] Optionally, each of the cartridge valves, each of the pilot directional valves, and the connecting oil circuits are integrated on the same valve block.

[0013] A cylinder driving method is also provided, applied to the hydraulic differential circuit integrated system described above, comprising the following steps: When both pilot directional valves are de-energized, the first cartridge valve and the third cartridge valve are closed, the second cartridge valve and the fourth cartridge valve are opened, the plug chamber and the rod chamber of the cylinder are connected to the main return port, and the cylinder is stationary; When both pilot directional valves are energized, the first cartridge valve and the third cartridge valve open, and the second cartridge valve and the fourth cartridge valve close. The oil in the main inlet enters the plug chamber through the third cartridge valve, and the oil discharged from the rod chamber enters the plug chamber through the first cartridge valve and the third cartridge valve. The cylinder then moves forward differentially. When the first pilot directional valve is de-energized and the second pilot directional valve is energized, the first cartridge valve closes and the second cartridge valve opens. The oil discharged from the rod chamber flows back to the main return port through the second cartridge valve, and the cylinder moves forward without differential operation. When the first pilot directional valve is energized and the second pilot directional valve is de-energized, the first cartridge valve opens and the fourth cartridge valve opens. The oil in the main inlet enters the rod chamber through the first cartridge valve, and the oil discharged from the plug chamber flows back to the main return port through the fourth cartridge valve. The cylinder retracts.

[0014] The present invention achieves the following technical effects compared to the prior art: This invention uses two pilot-operated directional valves to control four cartridge valves. Each pilot-operated directional valve has two pilot working ports connected to the pilot ports of two different cartridge valves, thus achieving a pilot control structure. A single directional valve action can simultaneously control the opening and closing of two cartridge valves, significantly reducing the number of pilot control components and lowering manufacturing costs. In the main oil circuit, the four cartridge valves are interconnected to form a differential circuit: the main inlet is simultaneously connected to the second main port of the first cartridge valve and the second main port of the third cartridge valve; the cylinder's rod chamber is connected to the first main port of the first and second cartridge valves; and the cylinder's plug chamber is connected to the second main port of the third cartridge valve and the first main port of the fourth cartridge valve. By combining the opening and closing of each cartridge valve, the working state of the cylinder can be flexibly switched. By simultaneously controlling the opening and closing of at least four cartridge valves with at least two pilot-operated directional valves, the cylinder can switch between four states: stationary, differential forward, non-differential forward, and retracted, saving equipment manufacturing costs and improving system stability and integration. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a connection diagram of a hydraulic differential circuit integrated system in one example disclosed in this invention; The components are as follows: 1-Circuit body; 2-Main oil inlet; 3-Main oil return port; 4-Oil cylinder; 5-First cartridge valve; 6-Second cartridge valve; 7-Third cartridge valve; 8-Fourth cartridge valve; 9-First pilot directional valve; 10-Second pilot directional valve; 11-First check valve; 12-First pressure gauge; 13-Second pressure gauge; 14-Second check valve; 15-Third check valve. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The purpose of this invention is to provide a hydraulic differential circuit integrated system and a cylinder driving method to solve the problems existing in the prior art. It can achieve coordinated control of multiple cartridge valves with fewer pilot control elements, reduce manufacturing costs, and improve system integration and operational stability while realizing the differential speed-up function of the cylinder.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, this embodiment provides a hydraulic differential circuit integrated system, including a circuit body 1, four cartridge valves, and two pilot directional valves; the circuit body 1 is provided with a main oil inlet 2 and a main oil return port 3; the four cartridge valves are all installed on the circuit body 1, and each cartridge valve is provided with a first main oil port, a second main oil port, and a pilot port; the two pilot directional valves are all installed on the circuit body 1, and each pilot directional valve is provided with a pilot oil inlet port, a pilot oil return port, a first pilot working oil port, and a second pilot working oil port; wherein, oil... Cylinder 4 is provided with a plug chamber and a rod chamber; the first main oil port of the first cartridge valve 5 is connected to the rod chamber, and the second main oil port is connected to the second main oil port of the third cartridge valve 7; the first main oil port of the third cartridge valve 7 is connected to the plug chamber; the first main oil port of the second cartridge valve 6 is connected to the rod chamber, and the second main oil port is connected to the total return oil port 3; the first main oil port of the fourth cartridge valve 8 is connected to the plug chamber, and the second main oil port is connected to the total return oil port 3; the total oil inlet 2 is connected to the second main oil port of both the first cartridge valve 5 and the third cartridge valve 7.

[0021] The pilot inlet of the first pilot directional valve 9 and the pilot inlet of the second pilot directional valve 10 are both connected to the main inlet 2 through the pilot control oil circuit. The pilot return port of the first pilot directional valve 9 and the pilot return port of the second pilot directional valve 10 are both connected to the main return port 3. The first pilot working port of the first pilot directional valve 9 is connected to the pilot port of the first cartridge valve 5, and the second pilot working port of the first pilot directional valve 9 is connected to the pilot port of the second cartridge valve 6. The first pilot working port of the second pilot directional valve 10 is connected to the pilot port of the third cartridge valve 7, and the second pilot working port of the second pilot directional valve 10 is connected to the pilot port of the fourth cartridge valve 8.

[0022] This invention controls four cartridge valves separately using two pilot directional valves. Each pilot directional valve has two pilot working ports connected to the pilot ports of two different cartridge valves, thus achieving a pilot control structure. A single directional valve action can simultaneously control the opening and closing of two cartridge valves, significantly reducing the number of pilot control components and lowering manufacturing costs. In the main oil circuit, the four cartridge valves are interconnected to form a differential circuit: the main inlet 2 is simultaneously connected to the second main port of the first cartridge valve 5 and the second main port of the third cartridge valve 7; the rod chamber of the cylinder 4 is connected to the first main port of the first cartridge valve 5 and the first main port of the second cartridge valve 6; and the plug chamber of the cylinder 4 is connected to the first main port of the third cartridge valve 7 and the first main port of the fourth cartridge valve 8. The operating state of the cylinder 4 can be flexibly switched through the opening and closing combinations of each cartridge valve. By simultaneously controlling the opening and closing of at least four cartridge valves with at least two pilot-operated directional valves, the hydraulic cylinder 4 can switch between four states: stationary, differential forward, non-differential forward, and retracted, thereby saving equipment manufacturing costs and improving system stability and integration.

[0023] In one embodiment, each cartridge valve is a two-way cartridge valve. The two-way cartridge valve includes a valve core, a valve sleeve, and a spring. The valve core slides within the valve sleeve under the combined action of pilot oil pressure and spring force, controlling the connection and disconnection between the first main oil port and the second main oil port. When there is no pressurized oil at the pilot port, the valve core, under the action of the spring force, isolates the first main oil port from the second main oil port, and the cartridge valve is in the closed state. When the pilot port is depressurized and pressurized oil is present on the first main oil port side, the valve core is pushed by the pressurized oil, connecting the first main oil port and the second main oil port, and the cartridge valve is in the open state. The two-way cartridge valve has a simple structure, large flow capacity, and fast response speed, making it suitable for high-flow hydraulic systems. Using a standard two-way cartridge valve as the main valve facilitates system integration and maintenance. Furthermore, each cartridge valve's pilot port requires only a small pilot oil pressure to control the large flow connection and disconnection of the main oil circuit, achieving the function of controlling large flow with small inputs.

[0024] In one embodiment, each pilot directional valve is a two-position four-way solenoid directional valve; the first pilot directional valve 9 is a first two-position four-way solenoid directional valve, and the second pilot directional valve 10 is a second two-position four-way solenoid directional valve; the first pilot working port of the first two-position four-way solenoid directional valve is port A, the second pilot working port is port B, the pilot inlet port is port P, and the pilot return port is port T; the first pilot working port of the second two-position four-way solenoid directional valve is port A, the second pilot working port is port B, the pilot inlet port is port P, and the pilot return port is port T; port A of the first two-position four-way solenoid directional valve is connected to the pilot port of the first cartridge valve, and port B is connected to the pilot port of the second cartridge valve; port A of the second two-position four-way solenoid directional valve is connected to the pilot port of the third cartridge valve, and port B is connected to the pilot port of the fourth cartridge valve.

[0025] In the de-energized state, the P port of the two-position four-way solenoid directional valve is normally open to both the A and B ports, and normally open to both the T and B ports. In the energized state, the P port is normally open to both the B and A ports, and normally open to both the T and B ports. The A and B ports of the two two-position four-way solenoid directional valves are connected to the pilot ports of four different cartridge valves, forming a cross-connected pilot control network. When the solenoid directional valve is activated, its two working ports switch pressure states simultaneously. One port switches from the return oil state to the pilot pressure state, and the other port switches from the pilot pressure state to the return oil state, thereby simultaneously changing the opening and closing states of the two cartridge valves.

[0026] In one embodiment, a first check valve 11 is also included. The first check valve 11 is disposed in the pilot control oil circuit and is used to allow the oil from the main oil inlet 2 to flow unidirectionally into the P ports of the first two-position four-way solenoid directional valve and the second two-position four-way solenoid directional valve. The first check valve 11 is disposed in the pilot control oil circuit between the main oil inlet 2 and the P ports of the two solenoid directional valves, and its conduction direction is from the main oil inlet 2 to each P port. The first check valve 11 prevents the oil in the pilot control oil circuit from flowing back to the main oil inlet 2, ensuring the stability of the pilot control pressure. When the pressure of the main oil circuit of the system fluctuates, the first check valve 11 isolates the mutual interference between the main oil circuit and the pilot control oil circuit, ensuring that the pilot control signals of each cartridge valve are stable and reliable.

[0027] In one embodiment, the second check valve 14 is connected to the control oil circuit between port A of the first two-position four-way solenoid directional valve and port B of the second two-position four-way solenoid directional valve, for allowing oil to flow unidirectionally from port A of the first two-position four-way solenoid directional valve to port B of the second two-position four-way solenoid directional valve; the third check valve 15 is connected to the control oil circuit between port A of the second two-position four-way solenoid directional valve and port B of the first two-position four-way solenoid directional valve, for allowing oil to flow unidirectionally from port A of the second two-position four-way solenoid directional valve to port B of the first two-position four-way solenoid directional valve; the second check valve 14 and the third check valve 15 constitute a cross-connected pilot oil circuit interlock valve group; when the first two When port A of the four-way solenoid directional valve is under pilot pressure, the pilot oil, in addition to controlling the first cartridge valve, also flows through the second check valve 14 to port B of the second four-way solenoid directional valve, providing auxiliary control for the pilot port of the fourth cartridge valve. Conversely, when port A of the second four-way solenoid directional valve is under pilot pressure, the pilot oil flows through the third check valve 15 to port B of the first four-way solenoid directional valve, providing auxiliary control for the pilot port of the second cartridge valve. The cross-connected check valve group ensures that the pilot oil flows unidirectionally in a predetermined direction under different operating conditions, preventing backflow interference between pilot oil circuits and ensuring the correctness and stability of the system logic.

[0028] In one embodiment, a first pressure gauge 12 is also included. The first pressure gauge 12 is located in the oil line between the rod chamber of the cylinder 4 and the first cartridge valve, and is used to monitor the pressure in the rod chamber. The pressure in the rod chamber of the cylinder 4 reflects the working state of the cylinder 4 when it retracts and the back pressure of the oil discharged from the rod chamber when it moves forward differentially. The first pressure gauge 12 is directly connected to the oil line between the rod chamber and the first cartridge valve, and can display the rod chamber pressure in real time. The operator can judge whether the working state of the cylinder 4 is normal based on the pressure value.

[0029] In one embodiment, a second pressure gauge 13 is also included. The second pressure gauge 13 is located in the oil line between the plug cavity of the cylinder 4 and the third cartridge valve, and is used to monitor the pressure of the plug cavity. The pressure of the plug cavity of the cylinder 4 is a direct reflection of the forward thrust of the cylinder 4. The second pressure gauge 13 displays the plug cavity pressure in real time, and the operator can judge whether the oil inlet pressure is normal and whether the load of the cylinder 4 meets the expectations based on the pressure value. The two pressure gauges monitor the rod cavity and the plug cavity respectively, providing complete pressure information on both sides of the cylinder 4, which facilitates system debugging and operation monitoring.

[0030] In one embodiment, the pilot control branch between each pilot port and its corresponding A port or B port is integrated inside the loop body 1. By integrating each pilot control branch inside the loop body 1, the connection between each pilot port and its corresponding pilot working port is realized through the internal oil passage, which greatly reduces the number of external pipelines and joints and improves the system's integration and sealing reliability. The internal oil passage is not directly affected by external mechanical collisions and vibrations, and the transmission of pilot control signals is more stable.

[0031] In one embodiment, each cartridge valve, each pilot directional valve, and connecting oil circuit are integrated onto the same valve block. Integrating four cartridge valves, two pilot directional valves, and all main oil circuits and pilot control oil circuits onto a single valve block constitutes a compact hydraulic integrated system. The integrated valve block design eliminates the large number of pipelines required by traditional tubular connections, reduces oil leakage points, and lowers the complexity of assembly and maintenance. The integrated layout significantly reduces the overall size of the system, facilitating installation and placement on equipment. Simultaneously, the modular structure of the integrated valve block facilitates later inspection and maintenance; when a component needs replacement, only the corresponding component needs to be removed and installed from the valve block, without affecting the normal operation of other parts.

[0032] Furthermore, the present invention also provides a method for driving a hydraulic cylinder 4, applying the hydraulic differential circuit integrated system described in any of the above embodiments, comprising the following steps: When both pilot directional valves are de-energized, the P port and A port of each pilot directional valve are normally connected, and the B port and T port are normally connected. The system oil enters from the main inlet 2, passes through the first check valve 11, enters the P port of the two pilot directional valves, and then passes through their respective P ports to the A port, reaching the pilot ports of the first cartridge valve 5 and the third cartridge valve 7 respectively, thus closing the first cartridge valve 5 and the third cartridge valve 7. The pilot ports of the second cartridge valve 6 and the fourth cartridge valve 8 are respectively connected to the B port of the corresponding pilot directional valve, and are connected to the main return port 3 through the T port, thus opening the second cartridge valve 6 and the fourth cartridge valve 8. At this time, the plug chamber and rod chamber of the cylinder 4 are connected to the main return port 3 through the opened second cartridge valve 6 and the fourth cartridge valve 8, and the cylinder 4 is stationary.

[0033] When both pilot directional valves are energized, the P port and B port of each pilot directional valve are normally connected, and the A port and T port are normally connected. The system oil enters from the main inlet 2, passes through the first check valve 11, enters the P port of the two pilot directional valves, and then passes through their respective P ports to the B port, reaching the pilot ports of the second cartridge valve 6 and the fourth cartridge valve 8 respectively, causing the second cartridge valve 6 and the fourth cartridge valve 8 to close. The pilot ports of the first cartridge valve 5 and the third cartridge valve 7 are respectively connected to the A port of the corresponding pilot directional valve, and are connected to the main return port 3 through the T port, causing the first cartridge valve 5 and the third cartridge valve 7 to open. At this time, the oil in the main inlet 2 enters the plug chamber through the third cartridge valve 7, and the oil discharged from the rod chamber enters the plug chamber through the first cartridge valve 5 and the third cartridge valve 7, causing the cylinder 4 to move forward differentially.

[0034] When the first pilot directional valve 9 is de-energized and the second pilot directional valve 10 is energized, the P port of the first pilot directional valve 9 is normally connected to the A port and the B port is normally connected to the T port, and the P port of the second pilot directional valve 10 is normally connected to the B port and the A port is normally connected to the T port. The pilot oil pressure at the A port of the first pilot directional valve 9 acts on the pilot port of the first cartridge valve 5, causing the first cartridge valve 5 to close. The B port of the first pilot directional valve 9 is connected to the total return port 3 via the T port, the pilot port of the second cartridge valve 6 is depressurized, and the second cartridge valve 6 opens. The oil discharged from the rod chamber flows back to the total return port 3 via the second cartridge valve 6, and the cylinder 4 moves forward without differential movement.

[0035] When the first pilot directional valve 9 is energized and the second pilot directional valve 10 is de-energized, the P port and B port of the first pilot directional valve 9 are normally connected, and the A port and T port are normally connected; the P port and A port of the second pilot directional valve 10 are normally connected, and the B port and T port are normally connected. The pilot oil pressure at the B port of the first pilot directional valve 9 acts on the pilot port of the second cartridge valve 6, causing the second cartridge valve 6 to close. The A port of the first pilot directional valve 9 is connected to the main return port 3 via the T port. The pilot port of valve 5 is depressurized, and the first cartridge valve 5 opens; the pilot oil pressure at port A of the second pilot directional valve 10 acts on the pilot port of the third cartridge valve 7, causing the third cartridge valve 7 to close; port B of the second pilot directional valve 10 is connected to the main return port 3 via port T, the pilot port of the fourth cartridge valve 8 is depressurized, and the fourth cartridge valve 8 opens; the oil in the main inlet port 2 enters the rod chamber through the first cartridge valve 5, and the oil discharged from the plug chamber flows back to the main return port 3 through the fourth cartridge valve 8, and the cylinder 4 retracts.

[0036] This hydraulic cylinder 4 driving method controls the opening and closing combinations of four cartridge valves by switching the energized and de-energized states of two pilot directional valves, achieving flexible switching between four states: stationary, differential forward, non-differential forward, and retracted. When both pilot directional valves are energized simultaneously, the first cartridge valve 5 and the third cartridge valve 7 open, forming a differential circuit. The oil discharged from the rod chamber does not flow back to the oil tank but instead enters the plug chamber, increasing the effective flow rate into the plug chamber, and the hydraulic cylinder 4 advances rapidly. When one of the pilot directional valves is de-energized, the differential circuit is disconnected, the oil discharged from the rod chamber flows directly back to the oil tank, and the hydraulic cylinder 4 switches to slow working feed. When the energized states of the two pilot directional valves reverse, the oil inlet and return paths reverse, and the hydraulic cylinder 4 retracts. The two pilot directional valves control the opening and closing of the two cartridge valves simultaneously through a single action, resulting in clear control logic, fast response speed, and high system stability and reliability.

[0037] In summary, this invention addresses the problems of high cost and low efficiency associated with single pilot valve control of two-way cartridge valves in existing hydraulic systems. It provides an integrated hydraulic differential circuit system. The circuit body 1 is equipped with four cartridge valves and two pilot directional valves. Each pilot directional valve's two pilot working ports are connected to the pilot ports of two different cartridge valves to achieve pilot control. The main ports of the four cartridge valves are connected to the plug chamber and rod chamber of the cylinder 4, as well as the total inlet port 2 and the total return port 3, in a predetermined manner to form a hydraulic differential circuit. This enables: firstly, two pilot... The directional valves simultaneously control the opening and closing of two cartridge valves, allowing for simultaneous switching of the two cartridge valve states with a single directional action. This reduces the number of pilot control elements and saves manufacturing costs. Secondly, when the first cartridge valve 5 and the third cartridge valve 7 are open simultaneously, they form a differential path. Oil discharged from the rod chamber of cylinder 4 flows through the first cartridge valve 5 and the third cartridge valve 7 into the plug chamber, achieving rapid differential forward movement. Thirdly, the four cartridge valves, two pilot directional valves, and all connecting oil circuits are integrated onto the same valve block, resulting in a compact structure and simplified piping, which facilitates equipment inspection and maintenance.

[0038] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0039] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0040] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A hydraulic differential circuit integrated system, characterized in that, include: The circuit body is equipped with a main oil inlet and a main oil return port; Four cartridge valves are installed on the circuit body, and each cartridge valve is provided with a first main oil port, a second main oil port and a pilot port; Two pilot directional valves are installed on the circuit body. Each pilot directional valve is provided with a pilot inlet, a pilot return port, a first pilot working port, and a second pilot working port. The cylinder is provided with a plug chamber and a rod chamber; the first main oil port of the first cartridge valve is connected to the rod chamber, and the second main oil port is connected to the second main oil port of the third cartridge valve; the first main oil port of the third cartridge valve is connected to the plug chamber; the first main oil port of the second cartridge valve is connected to the rod chamber, and the second main oil port is connected to the total return oil port; the first main oil port of the fourth cartridge valve is connected to the plug chamber, and the second main oil port is connected to the total return oil port. The main oil inlet is connected to both the second main oil inlet of the first cartridge valve and the second main oil inlet of the third cartridge valve; The pilot inlet ports of the first and second pilot directional valves are both connected to the main inlet port via pilot control oil circuits. The pilot return ports of the first and second pilot directional valves are both connected to the main return port. The first pilot working port of the first pilot directional valve is connected to the pilot port of the first cartridge valve, and the second pilot working port of the first pilot directional valve is connected to the pilot port of the second cartridge valve. The first pilot working port of the second pilot directional valve is connected to the pilot port of the third cartridge valve, and the second pilot working port of the second pilot directional valve is connected to the pilot port of the fourth cartridge valve.

2. The hydraulic differential circuit integrated system according to claim 1, characterized in that, All of the cartridge valves mentioned are two-way cartridge valves.

3. The hydraulic differential circuit integrated system according to claim 2, characterized in that, All of the pilot directional valves are two-position four-way solenoid directional valves; the first pilot directional valve is a first two-position four-way solenoid directional valve, and the second pilot directional valve is a second two-position four-way solenoid directional valve. The first pilot working port of the first and second position four-way solenoid directional valve is port A, the second pilot working port is port B, the pilot inlet port is port P, and the pilot return port is port T. The first pilot working port of the second two-position four-way solenoid directional valve is port A, the second pilot working port is port B, the pilot inlet port is port P, and the pilot return port is port T. The A port of the first two-position four-way solenoid directional valve is connected to the pilot port of the first cartridge valve, and the B port is connected to the pilot port of the second cartridge valve. The A port of the second two-position four-way solenoid directional valve is connected to the pilot port of the third cartridge valve, and the B port is connected to the pilot port of the fourth cartridge valve.

4. The hydraulic differential circuit integrated system according to claim 3, characterized in that, It also includes a first check valve, which is located in the pilot control oil circuit and is used to allow the oil from the main inlet to flow unidirectionally into the P port of the first two-position four-way solenoid directional valve and the P port of the second two-position four-way solenoid directional valve.

5. The hydraulic differential circuit integrated system according to claim 3, characterized in that, It also includes a second check valve and a third check valve; The second check valve is connected in the control oil circuit between port A of the first two-position four-way solenoid valve and port B of the second two-position four-way solenoid valve, and is used to allow oil to flow unidirectionally from port A of the first two-position four-way solenoid valve to port B of the second two-position four-way solenoid valve. The third check valve is connected in the control oil circuit between port A of the second two-position four-way solenoid valve and port B of the first two-position four-way solenoid valve, and is used to allow oil to flow unidirectionally from port A of the second two-position four-way solenoid valve to port B of the first two-position four-way solenoid valve.

6. The hydraulic differential circuit integrated system according to claim 3, characterized in that, It also includes a first pressure gauge, which is located in the oil line between the rod chamber of the cylinder and the first cartridge valve, and is used to monitor the pressure in the rod chamber.

7. The hydraulic differential circuit integrated system according to claim 3, characterized in that, It also includes a second pressure gauge, which is located in the oil line between the plug chamber of the oil cylinder and the third cartridge valve, and is used to monitor the pressure in the plug chamber.

8. The hydraulic differential circuit integrated system according to claim 3, characterized in that, The pilot control branch between each of the pilot ports and the corresponding A port or B port is integrated inside the loop body.

9. The hydraulic differential circuit integrated system according to claim 1, characterized in that, Each of the cartridge valves, each of the pilot directional valves, and the connecting oil circuits are integrated on the same valve block.

10. A method for differential control of hydraulic cylinders in a hydraulic differential circuit integrated system, applied to the hydraulic differential circuit integrated system according to any one of claims 1 to 9, characterized in that, Includes the following steps: When both pilot directional valves are de-energized, the first cartridge valve and the third cartridge valve are closed, the second cartridge valve and the fourth cartridge valve are opened, the plug chamber and the rod chamber of the cylinder are connected to the main return port, and the cylinder is stationary; When both pilot directional valves are energized, the first cartridge valve and the third cartridge valve open, and the second cartridge valve and the fourth cartridge valve close. The oil in the main inlet enters the plug chamber through the third cartridge valve, and the oil discharged from the rod chamber enters the plug chamber through the first cartridge valve and the third cartridge valve. The cylinder then moves forward differentially. When the first pilot directional valve is de-energized and the second pilot directional valve is energized, the first cartridge valve closes and the second cartridge valve opens. The oil discharged from the rod chamber flows back to the main return port through the second cartridge valve, and the cylinder moves forward without differential operation. When the first pilot directional valve is energized and the second pilot directional valve is de-energized, the first cartridge valve opens and the fourth cartridge valve opens. The oil in the main inlet enters the rod chamber through the first cartridge valve, and the oil discharged from the plug chamber flows back to the main return port through the fourth cartridge valve. The cylinder retracts.

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