Hydraulic circuit capable of flexibly switching high pressure and low pressure

Abstract

The utility model discloses a high-low pressure flexible switching hydraulic circuit, which belongs to the technical field of hydraulic systems and comprises a two-position four-way reversing valve, a pilot pressure reducing valve and a three-position four-way reversing valve, a P port of the two-position four-way reversing valve is communicated with an oil supply port of an oil supply pipeline, a T port of the two-position four-way reversing valve is communicated with an A port of the pilot pressure reducing valve, and a B port of the three-position four-way reversing valve is communicated with a C port of the pilot pressure reducing valve. A port A of the pilot pressure reducing valve is communicated with an oil supply port, a port B of the pilot pressure reducing valve is communicated with an oil supply port, a port A of the two-position four-way reversing valve is communicated with a port P of the three-position four-way reversing valve, a port B of the two-position four-way reversing valve is closed, a port A of the three-position four-way reversing valve is communicated with an oil cylinder piston cavity, a port B of the three-position four-way reversing valve is communicated with an oil cylinder rod cavity, and a port T of the three-position four-way reversing valve is communicated with an oil return port of the oil return pipeline. Through cooperation of the two-position four-way reversing valve and the first-arriving pressure reducing valve, flexible switching of high pressure and low pressure of the hydraulic loop can be achieved, and the problem that a traditional single hydraulic loop only has high pressure control or low pressure control is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic systems, in particular to a high- and low-pressure flexible switching hydraulic circuit. Background Art

[0002] Hydraulic systems play a vital role in the machinery manufacturing industry. A complete hydraulic system consists of five components: power elements, actuators, control elements, auxiliary elements, and hydraulic oil. Depending on the specific application, appropriate control elements can be appropriately selected to achieve optimal results. Traditional single hydraulic circuits offer only high-pressure control, enabling rapid cylinder adjustment, or only low-pressure control, enabling slow cylinder adjustment. However, these circuits are unable to effectively address special situations requiring both rapid and slow cylinder adjustment. Utility Model Content

[0003] The purpose of the utility model is to solve the above-mentioned technical problems and provide a hydraulic circuit with flexible switching between high and low pressures. Through the cooperation of a two-position four-way reversing valve and a first-arrival pressure reducing valve, flexible switching of high and low pressures of the hydraulic circuit can be achieved, solving the problem that a traditional single hydraulic circuit has only high-pressure control or only low-pressure control.

[0004] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention discloses a high-low pressure flexible switching hydraulic circuit, including a two-position four-way reversing valve, a pilot pressure reducing valve and a three-position four-way reversing valve, the P port of the two-position four-way reversing valve is connected to the oil supply port of the oil supply pipeline, the T port of the two-position four-way reversing valve is connected to the A port of the pilot pressure reducing valve, the B port of the pilot pressure reducing valve is connected to the oil supply port, the A port of the two-position four-way reversing valve is connected to the P port of the three-position four-way reversing valve, the B port of the two-position four-way reversing valve is closed, the A port of the three-position four-way reversing valve is connected to the oil cylinder plug chamber, the B port of the three-position four-way reversing valve is connected to the oil cylinder rod chamber, and the T port of the three-position four-way reversing valve is connected to the return oil port of the return oil pipeline.

[0005] Preferably, it includes a first one-way throttle valve and a second one-way throttle valve, the A port of the three-position four-way reversing valve is connected to the cylinder plug chamber through the first one-way throttle valve, and the B port of the three-position four-way reversing valve is connected to the cylinder rod chamber through the second one-way throttle valve.

[0006] Preferably, the one-way throttle valve is a superimposed double one-way throttle valve.

[0007] Preferably, a counterbalance valve is included, and the port A of the three-position four-way reversing valve and the first one-way throttle valve are connected through the counterbalance valve.

[0008] Preferably, the T port of the three-position four-way reversing valve is connected to the oil return port through a one-way valve.

[0009] Preferably, the two-position four-way reversing valve and the three-position four-way reversing valve are electro-hydraulic valves, solenoid valves or pneumatic valves.

[0010] Preferably, the two-position four-way reversing valve is an electro-hydraulic valve, and the Y port of the two-position four-way reversing valve and the Y port of the pilot pressure reducing valve are both connected to the oil drain port of the oil drain pipeline.

[0011] Compared with the prior art, the utility model has achieved the following technical effects:

[0012] After the oil pump is turned on, the oil pump will be turned off, and the oil pressure will be adjusted accordingly.This method is convenient for oil pump to control and adjust the oil pressure.It can also be used to adjust the oil pressure of the oil pump to the desired level. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. 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 any creative work.

[0014] Figure 1 Structural diagram of a high- and low-pressure flexible switching hydraulic circuit;

[0015] Figure 2 Structural diagram of the high-pressure regulation process of a high-pressure and low-pressure flexible switching hydraulic circuit;

[0016] Figure 3 Structural diagram of the low-pressure regulation process in a high- and low-pressure flexible switching hydraulic circuit.

[0017] Explanation of the accompanying symbols: 1. Pilot pressure reducing valve; 2. Two-position four-way reversing valve; 3. Three-position four-way reversing valve; 4. Counterbalancing valve; 5. First superimposed double one-way throttle valve; 6. Second superimposed double one-way throttle valve; 7. One-way valve. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0019] This embodiment provides a high-low pressure flexible switching hydraulic circuit, such as Figures 1 to 3 As shown, it includes a pilot pressure-reducing valve 1, a two-position four-way directional valve 2, and a three-position four-way directional valve 3. The oil supply port of the oil supply pipeline is connected to port B of the pilot pressure-reducing valve 1 and port P of the two-position four-way directional valve 2, respectively. Port A of the pilot pressure-reducing valve 1 is connected to port T of the two-position four-way directional valve 2. Port A of the two-position four-way directional valve 2 is connected to port P of the three-position four-way directional valve 3, and port B of the two-position four-way directional valve 2 is closed. Port A of the three-position four-way directional valve 3 is connected to the cylinder plug chamber, port B of the three-position four-way directional valve 3 is connected to the cylinder rod chamber, and port T of the three-position four-way directional valve 3 is connected to the oil return port of the oil return pipeline.

[0020] Working principle:

[0021] (1) High-pressure control (the P port of the two-position four-way directional valve 2 is connected to the A port, and the T port is connected to the B port):

[0022] (1) The process of controlling the extension of the piston rod of the oil cylinder (the P port of the three-position four-way reversing valve 3 is connected to the A port, and the T port is connected to the B port): the high-pressure oil from the oil supply line will pass through the P port and the A port of the two-position four-way reversing valve 2, the P port and the A port of the three-position four-way reversing valve 3, and then flow into the plug cavity of the oil cylinder to push the piston rod outward. The pressurized hydraulic oil in the oil cylinder rod cavity flows outward and flows through the B port and the T port of the three-position four-way reversing valve 3 into the return oil port, completing the adjustment of the oil cylinder.

[0023] (2) The retraction control process of the piston rod of the oil cylinder (the P port of the three-position four-way reversing valve 3 is connected to the B port, and the T port is connected to the A port): the high-pressure oil from the oil supply line will pass through the P port and B port of the two-position four-way reversing valve 2, the P port and B port of the three-position four-way reversing valve 3, and then flow into the oil cylinder rod chamber to push the piston rod back. The pressurized hydraulic oil in the oil cylinder plug chamber flows out and flows into the oil return port through the A port and T port of the three-position four-way reversing valve 3 in turn, completing the adjustment of the oil cylinder.

[0024] High-pressure control is mainly used to achieve rapid adjustment of the oil cylinder, that is, the actuator.

[0025] (2) Low-pressure control (the P port of the two-position four-way directional valve 2 is connected to the B port, and the T port is connected to the A port):

[0026] (1) The process of controlling the extension of the piston rod of the oil cylinder (the P port of the three-position four-way reversing valve 3 is connected to the A port, and the T port is connected to the B port): the high-pressure oil from the oil supply line will pass through the B port and the A port of the pilot pressure reducing valve 1, and then pass through the T port and the A port of the two-position four-way reversing valve 2, and reach the P port of the three-position four-way reversing valve 3. It will flow into the oil cylinder plug cavity from the A port of the three-position four-way reversing valve 3 to push the piston rod outward. The pressurized hydraulic oil in the oil cylinder rod cavity will flow out, and in turn pass through the B port and the T port of the three-position four-way reversing valve 3 to flow into the oil return port, completing the adjustment of the oil cylinder.

[0027] (2) The piston rod retraction control process of the oil cylinder (the P port of the three-position four-way reversing valve 3 is connected to the A port, and the T port is connected to the B port): the high-pressure oil from the oil supply line will pass through the B port and the A port of the pilot pressure reducing valve 1, and then pass through the T port and the A port of the two-position four-way reversing valve 2 to reach the P port of the three-position four-way reversing valve 3, and flow into the oil cylinder rod cavity from the B port of the three-position four-way reversing valve 3 to push the piston rod back. The pressurized hydraulic oil in the oil cylinder plug cavity flows out, and flows into the oil return port through the A port and the T port of the three-position four-way reversing valve 3 in turn, completing the adjustment of the oil cylinder.

[0028] Low-pressure control is mainly used to achieve slow adjustment of the oil cylinder, that is, the actuator.

[0029] In this embodiment, Figures 1 to 3 As shown, the system includes a first one-way throttle valve and a second one-way throttle valve. Port A of the three-position, four-way directional valve 3 communicates with the cylinder plug chamber through the first one-way throttle valve, regulating oil pressure and preventing oil backflow. Port B of the three-position, four-way directional valve 3 communicates with the cylinder rod chamber through the second one-way throttle valve, regulating oil pressure and preventing oil backflow.

[0030] Furthermore, in this embodiment, if Figures 1 to 3 As shown, the one-way throttle valve is a superimposed double one-way throttle valve, that is, the first one-way throttle valve is a first superimposed double one-way throttle valve 5, and the second one-way throttle valve is a second superimposed double one-way throttle valve 6.

[0031] Furthermore, in this embodiment, if Figures 1 to 3 As shown, the system also includes a counterbalance valve 4, which connects port A of the three-position, four-way directional valve 3 to the first one-way throttle valve (first superimposed double one-way throttle valve 5). A standard counterbalance valve can be used for this. By controlling ports ①, ②, and ③ of the standard counterbalance valve, the cylinder is lowered at a uniform speed, protecting the cylinder and personal and property safety.

[0032] In this embodiment, Figures 1 to 3 As shown, the T port of the three-position four-way reversing valve 3 is connected to the oil return port through a one-way valve 7 to prevent oil backflow.

[0033] In this embodiment, Figures 1 to 3As shown, the two-position four-way directional control valve 2 and the three-position four-way directional control valve 3 are electro-hydraulic valves, solenoid valves, or pneumatic valves. Preferably, the two-position four-way directional control valve 2 and the three-position four-way directional control valve 3 are electro-hydraulic valves, that is, the two-position four-way directional control valve 2 is a two-position four-way electro-hydraulic directional control valve, and the three-position four-way directional control valve 3 is a three-position four-way electro-hydraulic directional control valve.

[0034] Furthermore, in this embodiment, if Figures 1 to 3 As shown, when the two-position four-way directional valve 2 uses an electro-hydraulic valve, the Y port of the two-position four-way directional valve 2 and the Y port of the pilot pressure reducing valve 1 are both connected to the oil drain port of the oil drain pipeline.

[0035] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A high-low pressure flexible switching hydraulic circuit, characterized in that: It includes a two-position four-way reversing valve, a pilot pressure reducing valve and a three-position four-way reversing valve, the P port of the two-position four-way reversing valve is connected to the oil supply port of the oil supply pipeline, the T port of the two-position four-way reversing valve is connected to the A port of the pilot pressure reducing valve, the B port of the pilot pressure reducing valve is connected to the oil supply port, the A port of the two-position four-way reversing valve is connected to the P port of the three-position four-way reversing valve, the B port of the two-position four-way reversing valve is closed, the A port of the three-position four-way reversing valve is connected to the cylinder plug chamber, the B port of the three-position four-way reversing valve is connected to the cylinder rod chamber, and the T port of the three-position four-way reversing valve is connected to the return port of the oil return pipeline.

2. A high-low pressure flexible switching hydraulic circuit according to claim 1, characterized in that: It includes a first one-way throttle valve and a second one-way throttle valve. The A port of the three-position four-way reversing valve is connected to the cylinder plug chamber through the first one-way throttle valve, and the B port of the three-position four-way reversing valve is connected to the cylinder rod chamber through the second one-way throttle valve.

3. The high-low pressure flexible switching hydraulic circuit according to claim 2, characterized in that: The one-way throttle valve is a superimposed double one-way throttle valve.

4. A high-low pressure flexible switching hydraulic circuit according to claim 2 or 3, characterized in that: A counterbalance valve is included, and the port A of the three-position four-way reversing valve and the first one-way throttle valve are connected through the counterbalance valve.

5. The high-low pressure flexible switching hydraulic circuit according to claim 1, characterized in that: The T port of the three-position four-way reversing valve is connected to the oil return port through a one-way valve.

6. The high-low pressure flexible switching hydraulic circuit according to claim 1, characterized in that: The two-position four-way reversing valve and the three-position four-way reversing valve are electro-hydraulic valves, solenoid valves or pneumatic valves.

7. The high-low pressure flexible switching hydraulic circuit according to claim 6, characterized in that: The two-position four-way reversing valve is an electro-hydraulic valve, and the Y port of the two-position four-way reversing valve and the Y port of the pilot pressure reducing valve are both connected to the oil drain port of the oil drain pipeline.

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