High-pressure large-flow buffering hydraulic system and engineering machinery

Abstract

A high-pressure large-flow buffering hydraulic system comprises a switching valve, an oil cylinder, a first pressure sensor, a pressure release valve and a controller. The switching valve is connected to a rodless cavity of the oil cylinder through a first oil way and connected to a rod cavity of the oil cylinder through a second oil way, an oil inlet of the pressure release valve is connected to the first oil way, an oil outlet of the pressure release valve is connected with the oil return tank, and the first pressure sensor and the control end of the pressure release valve are both connected with the controller. The first pressure sensor is used for detecting oil pressure in the rodless cavity, generating a first oil pressure signal and sending the first oil pressure signal to the controller, and the controller opens the pressure relief valve according to the received first oil pressure signal so as to relieve pressure of the first oil way and control steering of the oil cylinder. The high-pressure large-flow buffering hydraulic system can reduce hydraulic impact, has a buffering effect on the oil cylinder, and protects the whole hydraulic system. The utility model further relates to engineering machinery with the high-pressure large-flow buffering hydraulic system.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering machinery, in particular to a high-pressure and large-flow buffer hydraulic system and an engineering machinery with the high-pressure and large-flow buffer hydraulic system. Background Art

[0002] In hydraulic systems, vibrations can be caused by the impact vibrations generated by the high-speed flow of hydraulic oil in pipelines, as well as the impact of oil during the rapid opening and closing of control valves. The sudden reversal of the reversing valve in the hydraulic system causes the high-pressure, high-flow main oil circuit to open and close instantly, resulting in the conversion of kinetic energy and pressure in the hydraulic system, which in turn produces significant hydraulic shock. Without proper deceleration, the hydraulic cylinder piston and cylinder head will mechanically collide, generating impact, noise, and destructive damage to the mechanical structure. This can also cause errors in system control actions and erroneous errors in some of the system's more sophisticated instruments, leading to system failure and potential safety hazards.

[0003] Figure 1 This is a schematic diagram of an existing high-pressure and high-flow hydraulic system. Figure 1 The existing high-pressure, high-flow hydraulic system includes an electro-hydraulic reversing valve 1, a balancing valve 2, a throttle valve 3, and a cylinder 4. Among them, the electro-hydraulic reversing valve 1 is a large-diameter electro-hydraulic reversing valve (a diameter greater than DN25 is usually called a large-diameter one, and a diameter of DN50 and above is usually considered a larger diameter, which has disadvantages such as large size and high price). When the electromagnet b of the electro-hydraulic reversing valve 1 is energized, the electro-hydraulic reversing valve 1 works in the right position, and the hydraulic oil from the oil tank enters the large chamber (rodless chamber) of the cylinder 4 through the throttle valve 3 and the electro-hydraulic reversing valve 1. The cylinder 4 moves to the right to push the load. The hydraulic oil in the small chamber (rod chamber) returns to the oil tank through the balancing valve 2 and the T port of the electro-hydraulic reversing valve 1. When the cylinder 4 pushes the load to the set position and needs to return. Electromagnet a in electro-hydraulic directional valve 1 is energized, causing valve 1 to shift direction and operate in the left position. Hydraulic oil flows through throttle valve 3, electro-hydraulic directional valve 1, and balancing valve 2 into the small chamber of cylinder 4, causing the piston rod of cylinder 4 to retract. The hydraulic oil in the large chamber of cylinder 4 returns through port T of electro-hydraulic directional valve 1. By reversing the direction of electro-hydraulic directional valve 1, cylinder 4 performs a reciprocating motion.

[0004] However, the prior art has the following disadvantages:

[0005] 1. When the electro-hydraulic directional valve 1 suddenly changes direction, the large chamber of the oil cylinder 4 is not depressurized, the pressure is high, and the hydraulic shock is relatively large, which not only easily damages the oil cylinder and valve, but also causes a lot of heat in the entire hydraulic system.

[0006] 2. When the electro-hydraulic directional valve 1 controls the reversing action of the oil cylinder 4, the reversing control can only be performed according to the pre-set time, and cannot be controlled according to the real-time working conditions. Utility Model Content

[0007] In view of this, the present invention provides a high-pressure, large-flow buffer hydraulic system and an engineering machine having the same, which can be used to solve the above-mentioned technical shortcomings.

[0008] The high-pressure and high-flow buffer pressure system provided by an embodiment of the utility model includes a switching valve and a cylinder, the switching valve is connected to the rodless chamber of the cylinder through a first oil circuit, and the switching valve is connected to the rod chamber of the cylinder through a second oil circuit. It also includes a first pressure sensor, a pressure relief valve and a controller, the oil inlet of the pressure relief valve is connected to the first oil circuit, and the oil outlet of the pressure relief valve is connected back to the oil tank, the first pressure sensor and the control end of the pressure relief valve are both connected to the controller, the first pressure sensor is used to detect the oil pressure in the rodless chamber and generate a first oil pressure signal to send to the controller, the controller opens the pressure relief valve according to the received first oil pressure signal to relieve the pressure of the first oil circuit and control the steering of the cylinder.

[0009] Furthermore, it also includes a first balancing valve and a one-way valve, the oil inlet of the first balancing valve is connected to the first oil circuit, the oil outlet of the first balancing valve is connected back to the mailbox, and the control end of the first balancing valve is connected to the second oil circuit; the one-way valve is arranged in the first oil circuit and is located between the first balancing valve and the switching valve, the oil inlet of the one-way valve is connected to the oil outlet of the switching valve; the pressure relief valve is connected to the oil circuit between the one-way valve and the oil cylinder.

[0010] Furthermore, a first pressure threshold is preset in the controller. When the first oil pressure rises to the first pressure threshold, the controller opens the pressure relief valve, and the controller simultaneously controls the steering of the oil cylinder or controls the steering of the oil cylinder after a preset time.

[0011] Furthermore, the controller is further configured to receive a command signal, and the controller adjusts the first pressure threshold according to the received command signal.

[0012] Furthermore, it also includes a throttle plug, which is arranged on the oil path between the first balancing valve and the pressure relief valve.

[0013] Furthermore, it includes a second balancing valve, the oil inlet of the second balancing valve is connected to one end of the second oil circuit close to the oil cylinder, the oil outlet of the second balancing valve is connected to one end of the second oil circuit close to the switching valve, and the control end of the second balancing valve is connected to the first oil circuit.

[0014] Furthermore, it also includes a second pressure sensor, which is connected to the controller. The second pressure sensor is used to detect the oil pressure in the rod chamber and generate a second oil pressure signal to send to the controller. The controller controls the steering of the cylinder according to the received second oil pressure signal.

[0015] Furthermore, a second pressure threshold is preset in the controller, and when the second oil pressure rises to the second pressure threshold, the controller controls the oil cylinder to turn.

[0016] Furthermore, the oil inlet of the switching valve is connected to the oil tank through a third oil circuit, and a throttle valve is provided on the third oil circuit.

[0017] The utility model also provides an engineering machine, comprising the above-mentioned high-pressure and large-flow buffer hydraulic system.

[0018] In summary, the high-pressure, high-flow buffer hydraulic system of the present invention includes a switching valve, an oil cylinder, a first pressure sensor, a pressure relief valve, and a controller. The switching valve is connected to the rodless chamber of the oil cylinder through the first oil circuit and to the rod chamber of the oil cylinder through the second oil circuit. The oil inlet of the pressure relief valve is connected to the first oil circuit, and the oil outlet is connected back to the oil tank. The first pressure sensor and the control end of the pressure relief valve are both connected to the controller. The first pressure sensor is used to detect the oil pressure in the rodless chamber and generate a first oil pressure signal to send to the controller. The controller opens the pressure relief valve according to the received first oil pressure signal to relieve the pressure of the first oil circuit and control the steering of the oil cylinder. The above-mentioned high-pressure, high-flow buffer hydraulic system relieves the pressure of the rodless chamber of the oil cylinder by setting a pressure relief valve, and the pressure relief process is controlled by the controller, so that the high-pressure, high-flow buffer hydraulic system has the following beneficial effects:

[0019] 1. It reduces hydraulic shock, provides a buffering effect on the oil cylinder, and protects the entire hydraulic system; at the same time, it also reduces the heat generated by the hydraulic system, which is green and energy-saving.

[0020] 2. It can reduce maintenance costs and increase the service life of the cylinder and solenoid valve.

[0021] 3. When the controller controls the switching valve reversing and then controls the reversing action of the oil cylinder, the control method can be adjusted according to different working conditions.

[0022] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In addition, in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a schematic diagram of an existing high-pressure and high-flow hydraulic system.

[0024] Figure 2 It is a schematic diagram of a high-pressure, large-flow buffer hydraulic system according to the first embodiment of the present invention.

[0025] Figure 3 It is a schematic diagram of a high-pressure, large-flow buffer hydraulic system according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the present invention, the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments.

[0027] [First embodiment]

[0028] Figure 2 This is a schematic diagram of the high-pressure and high-flow buffer hydraulic system of the first embodiment of the utility model. Figure 2 The high-pressure and high-flow buffer hydraulic system of this embodiment includes a switching valve 10, an oil cylinder 20, a first pressure sensor 31, a pressure relief valve 40, a controller 50, a first balancing valve 110 and a one-way valve 120.

[0029] Specifically, the switching valve 10 is, for example, a three-position, four-way solenoid directional valve, which is used to control the reciprocating motion of the cylinder 20. The first operating oil port A of the switching valve 10 is connected to the rodless chamber 21 of the cylinder 20 via a first oil passage 101. The second operating oil port B of the switching valve 10 is connected to the rod chamber 22 of the cylinder 20 via a second oil passage 102. The oil inlet P of the switching valve 10 is connected to the oil tank via a third oil passage 103. The oil return port T of the switching valve 10 is connected back to the oil tank via a fourth oil passage 104.

[0030] The oil cylinder 20 can be used for any actuator that needs to convert hydraulic energy into mechanical energy through linear reciprocating motion.

[0031] The pressure relief valve 40 is a switch valve. When the pressure relief valve 40 is open, the oil inlet and the oil outlet are connected. Otherwise, the pressure relief valve 40 is disconnected to realize the on-off of the oil circuit. The pressure relief valve 40 is specifically a two-position, two-way electromagnetic ball valve. The oil inlet of the pressure relief valve 40 is connected to the first oil circuit 101, and the oil outlet of the pressure relief valve 40 is connected back to the oil tank. Specifically in this embodiment, the oil outlet of the pressure relief valve 40 is connected to the fourth oil circuit 104 and then connected back to the oil tank. The control end (electrical control end) of the pressure relief valve 40 is connected to the controller 50. The controller 50 controls the working position of the pressure relief valve 40 by controlling the power supply and loss of the control end of the pressure relief valve 40 to open or close the pressure relief valve 40. When the control end of the pressure relief valve 40 is energized, the pressure relief valve 40 works in the right position, the oil inlet and the oil outlet of the pressure relief valve 40 are connected, and the pressure relief valve 40 is opened; when the control end of the pressure relief valve 40 loses power, the pressure relief valve 40 works in the left position, the oil inlet and the oil outlet of the pressure relief valve 40 are disconnected, and the pressure relief valve 40 is closed.

[0032] The first pressure sensor 31 can be connected to the first oil circuit 101 or to the rodless chamber 21 of the oil cylinder 20. In this embodiment, the first pressure sensor 31 is connected to the first oil circuit 101. The first pressure sensor 31 is also connected to the controller 50. The first pressure sensor 31 is used to detect the oil pressure in the rodless chamber 21 of the oil cylinder 20 and generate a first oil pressure signal to send to the controller 50. The first oil pressure signal is the current real-time data of the oil pressure in the rodless chamber 21. The controller 50 controls the opening of the pressure relief valve 40 according to the received first oil pressure signal to relieve the pressure in the first oil circuit 101 and control the steering of the oil cylinder 20.

[0033] Specifically, a first pressure threshold is preset in the controller 50. When the first oil pressure signal rises to the first pressure threshold, that is, when the current real-time data of the oil pressure in the rodless chamber 21 rises to be equal to the first pressure threshold, the controller 50 opens the pressure relief valve 40. At this time, the oil inlet and the oil outlet of the pressure relief valve 40 are connected, and part of the hydraulic oil in the first oil circuit 101 returns to the oil tank from the pressure relief valve 40 to relieve the pressure of the first oil circuit 101, thereby reducing the hydraulic shock in the rodless chamber 21 of the oil cylinder 20, playing a buffering role, and protecting the entire hydraulic system.

[0034] When the first oil pressure signal rises to the first pressure threshold, the controller 50 can also simultaneously control the oil cylinder 20 to rotate. In other embodiments, the controller 50 can also control the oil cylinder 20 to rotate after a preset time, that is, the time when the oil cylinder 20 rotates can be slightly later than the time when the pressure relief valve 40 opens.

[0035] Furthermore, the controller 50 is further configured to receive a command signal, and the controller 50 adjusts the first pressure threshold according to the received command signal. The command signal may be a signal manually input by an operator, or a signal preset in the controller 50 and adjustable for different working conditions.

[0036] When the switching valve 10 is a small-diameter (diameter less than or equal to DN25) reversing valve, a first balancing valve 110 with a large flow rate can be set to divert the hydraulic oil in the rodless chamber 21 of the cylinder 20 back to the oil tank, and a one-way valve 120 is set to prevent the hydraulic oil from flowing to the switching valve 10, thereby avoiding hydraulic shock to the small-diameter switching valve 10.

[0037] Specifically, the oil inlet of the first balancing valve 110 is connected to the first oil circuit 101, and the oil outlet of the first balancing valve 110 is connected back to the mailbox. Specifically in this embodiment, the oil outlet of the first balancing valve 110 is first connected to the fourth oil circuit 104 and then connected back to the mailbox. The control end (hydraulic control end) of the first balancing valve 110 is connected to the second oil circuit 102. When the oil pressure in the second oil circuit 102 rises, the first balancing valve 110 opens.

[0038] In this embodiment, the first balancing valve 110 is composed of a sequence valve and a one-way valve, wherein the oil inlet of the sequence valve is connected to the first oil circuit 101, the oil outlet of the sequence valve is connected to the fourth oil circuit 104, the oil inlet of the one-way valve is connected to one end of the oil outlet of the sequence valve, and the oil outlet of the one-way valve is connected to one end of the oil inlet of the sequence valve.

[0039] The one-way valve 120 is provided in the first oil circuit 101 and is located between the first balancing valve 110 and the switching valve 10. The oil inlet of the one-way valve 120 is connected to the oil outlet of the switching valve 10. The one-way valve 120 can reversely block the hydraulic oil returning from the rodless chamber 21 of the oil cylinder 20 from the first oil circuit 101.

[0040] The pressure relief valve 40 is connected to the oil circuit between the one-way valve 120 and the oil cylinder 20 . Specifically in this embodiment, the oil inlet of the pressure relief valve 40 is connected to the connection position between the first balancing valve 110 and the first oil circuit 101 .

[0041] Furthermore, the high-pressure, high-flow buffer hydraulic system also includes a throttle plug 130, which is disposed in the oil path between the first balancing valve 110 and the pressure relief valve 40. The throttle plug 130 is used to control the amount of hydraulic oil entering the pressure relief valve 40 to prevent the oil cylinder 20 from losing control due to excessive pressure relief.

[0042] Furthermore, the high-pressure, high-flow buffer hydraulic system also includes a second balancing valve 140. The oil inlet of the second balancing valve 140 is connected to the end of the second oil circuit 102 near the cylinder 20, and the oil outlet of the second balancing valve 140 is connected to the end of the second oil circuit 102 near the switching valve 10. The control end (hydraulic control end) of the second balancing valve 140 is connected to the first oil circuit 101. When the oil pressure in the first oil circuit 101 increases, the second balancing valve 140 opens. The second balancing valve 140 can effectively control the smooth movement of the cylinder 20 under the action of the load, preventing the movement from losing control due to the influence of load changes.

[0043] In this embodiment, the second balancing valve 140 is composed of a sequence valve and a one-way valve, wherein the oil inlet of the sequence valve is connected to one end of the second oil circuit 101 close to the oil cylinder 20, the oil outlet of the sequence valve is connected to one end of the second oil circuit 102 close to the switching valve 10, the oil inlet of the one-way valve is connected to one end of the oil outlet of the sequence valve, and the oil outlet of the one-way valve is connected to one end of the oil inlet of the sequence valve.

[0044] Furthermore, the high-pressure, large-flow buffer hydraulic system also includes a second pressure sensor 32, which is connected to the controller 50. The second pressure sensor 32 is used to detect the hydraulic oil pressure in the rod chamber 22 and send a second pressure signal to the controller 50. The controller 50 controls the steering of the oil cylinder 20 according to the received second pressure signal.

[0045] Furthermore, the oil inlet of the switching valve 10 is connected to the oil tank through the third oil circuit 103, and a throttle valve 150 is provided on the third oil circuit 103. The hydraulic flow can be controlled by changing the throttle section or throttle length of the throttle valve 150.

[0046] The working process of the high-pressure and high-flow buffer hydraulic system in this embodiment is as follows:

[0047] When electromagnet b of switching valve 10 is energized, switching valve 10 operates in the right position. Hydraulic oil from the tank enters third oil passage 103, passes through throttle valve 150, enters switching valve 10, and then from first oil passage 10 through check valve 120 into rodless chamber 21 of cylinder 20, driving the load to the right. At this time, first balancing valve 110 is closed, and pressure relief valve 40 is de-energized, allowing only pressurized oil to enter rodless chamber 21 of cylinder 20. Simultaneously, return oil from rodless chamber 22 of cylinder 20 passes through second balancing valve 140, port T of switching valve 10, and returns to the tank via fourth oil passage 104.

[0048] When the cylinder 20 drives the load to the set position and needs to return, the oil pressure in the rodless chamber 21 of the cylinder 20 will rise to the maximum value and will be detected by the first pressure sensor 31. The first pressure sensor 31 will detect the oil pressure and generate a first oil pressure signal and send it to the controller 50. The controller 50 compares the first oil pressure with the preset first pressure threshold for confirmation. If the first oil pressure and the preset first pressure threshold are equal, the controller 50 controls the pressure relief valve 40 to be energized, and the pressure relief valve 40 opens to first relieve the pressure in the rodless chamber of the cylinder 20.

[0049] Then, electromagnet a of switching valve 10 is energized, causing switching valve 10 to operate in the left position. Hydraulic oil from the tank enters third oil circuit 103, passes through throttle valve 150, enters switching valve 10, and then enters rod chamber 22 of cylinder 20 from second oil circuit 102 via second balancing valve 140, causing cylinder 20 to move leftward. The return oil from the rodless chamber of cylinder 20 is blocked by check valve 120, and the return oil is divided into two paths. One path is decompressed through throttle plug 130 and pressure relief valve 40. Due to the damping effect of throttle plug 130, pressure relief valve 40 only allows a small amount of oil to pass through, primarily to relieve pressure in rodless chamber 21 of cylinder 20. The other path, because the control end of first balancing valve 110 is opened by the pressure oil from second oil circuit 102, most of the hydraulic oil in rodless chamber 21 of cylinder 20 flows through the high-flow outlet of first balancing valve 110 into fourth oil circuit 104 before returning to the tank.

[0050] In this embodiment, the hydraulic oil in the rodless chamber 21 of the oil cylinder 20 is first relieved through the pressure relief valve 40 and then returned through the first balancing valve 110, rather than returning through the small-diameter switching valve 10. When the switching valve 10 switches direction, the hydraulic oil in the rodless chamber 21 has already been relieved through the pressure relief valve 40, reducing the hydraulic shock of the oil cylinder 20, activating a buffering effect, and protecting the entire hydraulic system.

[0051] In this embodiment, the switching valve 10, the pressure relief valve 40, the first balancing valve 110, the one-way valve 120, the throttle plug 130, the second balancing valve 140, the throttle valve 150 and part of the oil circuit are all integrated in the same valve block module. Since the switching valve 10 is a small-diameter solenoid valve, its volume is small, making the entire valve block module compact and low-cost.

[0052] The beneficial effects of the high-pressure, high-flow buffer hydraulic system of this embodiment are:

[0053] 1. It reduces hydraulic shock, provides a buffering effect on the oil cylinder, and protects the entire hydraulic system; at the same time, it also reduces the heat generated by the hydraulic system, which is green and energy-saving.

[0054] 2. It can reduce maintenance costs and increase the service life of the oil cylinder and the solenoid valve (switching valve 10).

[0055] 3. When the controller controls the switching valve reversing and then controls the reversing action of the oil cylinder, the control method can be adjusted according to different working conditions.

[0056] 4. A small-diameter solenoid valve (switching valve 10) can be used in large-flow situations, with a compact structure and low cost.

[0057] [Second embodiment]

[0058] Figure 3 This is a schematic diagram of a high-pressure, high-flow buffer hydraulic system according to the second embodiment of the present invention. Figure 3The difference between the high-pressure and high-flow buffer hydraulic system of this embodiment and the first embodiment is that the first balancing valve 110 and the one-way valve 120 are not provided, and the switching valve 10 adopts a large-diameter solenoid valve.

[0059] The working process of the high-pressure and high-flow buffer hydraulic system in this embodiment is as follows:

[0060] When electromagnet b of switching valve 10 is energized, switching valve 10 operates in the right position. Hydraulic oil from the tank enters third oil passage 103, passes through throttle valve 150, enters switching valve 10, and then enters rodless chamber 21 of cylinder 20 from first oil passage 10, driving the load to the right. At this time, pressure relief valve 40 is de-energized, allowing only pressurized oil to enter rodless chamber 21 of cylinder 20. Simultaneously, return oil from rod chamber 22 of cylinder 20 passes through second balancing valve 140, port T of switching valve 10, and returns to the tank via fourth oil passage 104.

[0061] When the cylinder 20 drives the load to the set position and needs to return, the oil pressure in the rodless chamber 21 of the cylinder 20 will rise to the maximum value and will be detected by the first pressure sensor 31. The first pressure sensor 31 will detect the oil pressure and generate a first oil pressure signal and send it to the controller 50. The controller 50 compares the first oil pressure with the preset first pressure threshold for confirmation. If the first oil pressure and the preset first pressure threshold are equal, the controller 50 controls the pressure relief valve 40 to be energized, and the pressure relief valve 40 opens to first relieve the pressure in the rodless chamber of the cylinder 20.

[0062] Then the electromagnet a of the switching valve 10 is energized, and the switching valve 10 works in the left position. After the hydraulic oil in the oil tank enters the third oil circuit 103, it passes through the throttle valve 150 and enters the switching valve 10, and then enters the rod chamber 22 of the oil cylinder 20 from the second oil circuit 102 through the second balancing valve 140, and the oil cylinder 20 moves to the left. The return oil from the rodless chamber of the oil cylinder 20 is divided into two routes. One route passes through the throttle plug 130 and the pressure relief valve 40 to relieve pressure. Due to the damping effect of the throttle plug 130, the pressure relief valve 40 only passes a small amount of oil, and its main purpose is to relieve pressure in the rodless chamber 21 of the oil cylinder 20; the other route passes through the T port of the switching valve 10 and then through the fourth oil circuit 104 and returns to the oil tank.

[0063] In this embodiment, because the pressure of the hydraulic oil in the rodless chamber 21 of the oil cylinder 20 is first relieved through the pressure relief valve 40 and then returned to the oil through the switching valve 10, when the switching valve 10 is reversed, the hydraulic oil in the rodless chamber 21 of the oil cylinder 20 has been relieved through the pressure relief valve 40 first, which also reduces the hydraulic shock of the oil cylinder 20, activates the buffering effect, and protects the entire hydraulic system.

[0064] The beneficial effects of the high-pressure, high-flow buffer hydraulic system of this embodiment are:

[0065] 1. It reduces hydraulic shock, provides a buffering effect on the oil cylinder, and protects the entire hydraulic system; it also reduces the heat generated by the hydraulic system, which is green and energy-saving.

[0066] 2. It can reduce maintenance costs and increase the service life of the oil cylinder and the solenoid valve (switching valve 10).

[0067] 3. When the controller controls the switching valve reversing and then controls the reversing action of the oil cylinder, the control method can be adjusted according to different working conditions.

[0068] The present invention also relates to an engineering machine, comprising the above-mentioned high-pressure and large-flow buffer hydraulic system. Other structures of the engineering machine are well known to those skilled in the art and will not be described in detail here.

[0069] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high-pressure, high-flow buffer hydraulic system, comprising a switching valve (10) and an oil cylinder (20), wherein the switching valve (10) is connected to a rodless chamber (21) of the oil cylinder (20) via a first oil circuit (101), and the switching valve (10) is connected to a rod chamber (22) of the oil cylinder (20) via a second oil circuit (102), characterized in that: It also includes a first pressure sensor (31), a pressure relief valve (40) and a controller (50), wherein the oil inlet of the pressure relief valve (40) is connected to the first oil circuit (101), and the oil outlet of the pressure relief valve (40) is connected back to the oil tank. The first pressure sensor (31) and the control end of the pressure relief valve (40) are both connected to the controller (50). The first pressure sensor (31) is used to detect the oil pressure in the rodless chamber (21) and generate a first oil pressure signal to send to the controller (50). The controller (50) opens the pressure relief valve (40) according to the received first oil pressure signal to relieve the pressure in the first oil circuit (101) and control the steering of the oil cylinder (20).

2. The high-pressure, high-flow buffer hydraulic system according to claim 1, characterized in that: The invention also includes a first balancing valve (110) and a one-way valve (120), wherein the oil inlet of the first balancing valve (110) is connected to the first oil circuit (101), the oil outlet of the first balancing valve (110) is connected back to the mailbox, and the control end of the first balancing valve (110) is connected to the second oil circuit (102); the one-way valve (120) is arranged in the first oil circuit (101) and is located between the first balancing valve (110) and the switching valve (10), and the oil inlet of the one-way valve (120) is connected to the oil outlet of the switching valve (10); and the pressure relief valve (40) is connected to the oil circuit between the one-way valve (120) and the oil cylinder (20).

3. The high-pressure, high-flow buffer hydraulic system according to claim 1 or 2, characterized in that: A first pressure threshold is preset in the controller (50). When the first oil pressure rises to the first pressure threshold, the controller (50) opens the pressure relief valve (40), and the controller (50) simultaneously controls the oil cylinder (20) to turn, or the controller (50) controls the oil cylinder (20) to turn after a preset time.

4. The high-pressure, high-flow buffer hydraulic system according to claim 3, characterized in that: The controller (50) is further configured to receive a command signal, and the controller (50) adjusts the first pressure threshold according to the received command signal.

5. The high-pressure, high-flow buffer hydraulic system according to claim 2, characterized in that: It also includes a throttle plug (130), which is arranged on the oil path between the first balancing valve (110) and the pressure relief valve (40).

6. The high-pressure, high-flow buffer hydraulic system according to claim 1 or 2, characterized in that: The invention also includes a second balancing valve (140), wherein the oil inlet of the second balancing valve (140) is connected to one end of the second oil circuit (102) close to the oil cylinder (20), the oil outlet of the second balancing valve (140) is connected to one end of the second oil circuit (102) close to the switching valve (10), and the control end of the second balancing valve (140) is connected to the first oil circuit (101).

7. The high-pressure, high-flow buffer hydraulic system according to claim 1 or 2, characterized in that: The invention also includes a second pressure sensor (32), which is connected to the controller (50). The second pressure sensor (32) is used to detect the oil pressure in the rod chamber (22) and generate a second oil pressure signal to send to the controller (50). The controller (50) controls the steering of the oil cylinder (20) according to the received second oil pressure signal.

8. The high-pressure, high-flow buffer hydraulic system according to claim 7, characterized in that: A second pressure threshold is preset in the controller (50), and when the second oil pressure rises to the second pressure threshold, the controller (50) controls the oil cylinder (20) to turn.

9. The high-pressure, high-flow buffer hydraulic system according to claim 1 or 2, characterized in that: The oil inlet of the switching valve (10) is connected to the oil tank via a third oil circuit (103), and a throttle valve (150) is provided on the third oil circuit (103).

10. An engineering machine, characterized in that: The invention comprises a high-pressure, large-flow buffer hydraulic system as described in any one of claims 1 to 9.

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