Hydraulic system and control method for an explosion relief valve of a working machine

Abstract

This application discloses a hydraulic system and control method for an explosion-proof valve in engineering machinery. The system includes: a solenoid valve assembly, comprising a bidirectional check valve and an electro-proportional pressure reducing valve; the bidirectional check valve includes: a first check valve, which unidirectionally connects the outlet of the solenoid valve assembly to the working port of the electro-proportional pressure reducing valve and has a first set pressure; a second check valve, which unidirectionally connects the working port of the electro-proportional pressure reducing valve to the outlet of the solenoid valve assembly; a controller is signal-connected to the electromagnet of the electro-proportional pressure reducing valve, controlling the electromagnet to be energized or de-energized, thereby switching the solenoid valve assembly between a first working state and a second working state; in the first working state, pilot pressure oil is output through the electro-proportional pressure reducing valve and the second check valve to the third port of the explosion-proof valve, allowing the oil in the explosion-proof valve to flow from the second port to the first port, completing the boom retraction action; in the second working state, a pilot pressure oil with the first set pressure is maintained between the third port of the explosion-proof valve and the solenoid valve assembly.

Description

Technical Field

[0001] This application belongs to the field of hydraulic control technology for engineering machinery, specifically relating to a hydraulic system and control method for an explosion-proof valve for engineering machinery. Background Technology

[0002] Hydraulic systems of construction machinery (such as material handling machines) are equipped with explosion-proof valves as standard to prevent accidental damage caused by pipe bursts. In related technologies, the explosion-proof valve is located between the oil cylinder and the main valve, including a logic check valve, a relief valve, and a pilot pressure oil circuit. The explosion-proof valve is often controlled by a pilot pressure oil circuit connected in parallel on the boom pilot handle.

[0003] The relevant technology has the following drawbacks: the booms of construction machinery are often very long, especially those of large construction machinery, which can reach lengths of over ten meters. This excessive boom length results in an excessively long pilot pressure oil line from the handle pilot to the boom explosion-proof valve. This causes the oil in the line to flow back to the oil tank due to gravity and other factors after the equipment has been stationary for a long time. If the boom retraction is then performed, the line needs to be refilled with oil, and the excessively long line will cause greater pressure loss, resulting in slower pressure build-up during boom retraction and causing a delay. This phenomenon is particularly noticeable when the oil temperature is low and the handle opening is small. Summary of the Invention

[0004] Objective: In view of at least one of the above technical problems, this application provides a hydraulic system and control method for explosion-proof valves in engineering machinery.

[0005] Technical solution: To solve the above-mentioned technical problems, the technical solution adopted in this application is as follows:

[0006] In one aspect, a hydraulic system for explosion-proof valves in engineering machinery is provided, including a solenoid valve assembly, an explosion-proof valve, and a controller;

[0007] The solenoid valve assembly includes a two-way check valve and an electro-proportional pressure reducing valve; wherein the two-way check valve includes:

[0008] The first check valve is a one-way valve that connects the oil outlet of the solenoid valve assembly to the working oil port of the electro-proportional pressure reducing valve, and has a first set pressure.

[0009] The second check valve is a one-way valve that connects the working port of the electro-proportional pressure reducing valve to the outlet port of the solenoid valve assembly, and has a second set pressure, which is less than the first set pressure.

[0010] The controller is connected to the electromagnet of the electro-proportional pressure reducing valve and is used to control the electromagnet of the electro-proportional pressure reducing valve to be energized or de-energized, thereby switching the solenoid valve group between the first working state and the second working state.

[0011] In the first working state, the electromagnet is energized, the electro-proportional pressure reducing valve is in the first working position, and the pilot pressure oil is output to the third port of the explosion-proof valve through the electro-proportional pressure reducing valve and the second check valve, so that the oil in the explosion-proof valve can flow from the second port to the first port, and the boom retraction action is completed.

[0012] In the second working state, the electromagnet is de-energized, the electro-proportional pressure reducing valve is in the second working position, the pilot pressure oil of the third port of the explosion-proof valve returns through the first check valve and the electro-proportional pressure reducing valve, and the first port of the explosion-proof valve is unidirectionally connected to the second port.

[0013] It should be noted that, in the second working state, due to the presence of the first check valve, there is pilot pressure oil with a first set pressure in the pipeline between the third port of the explosion-proof valve and the solenoid valve assembly.

[0014] In some embodiments, the solenoid valve assembly is further provided with an oil inlet and an oil return port;

[0015] When the electro-proportional pressure reducing valve is energized, the electro-proportional pressure reducing valve is in the first working position, the oil inlet of the electro-proportional pressure reducing valve is connected to the working oil port, and the pilot pressure oil of the oil inlet of the solenoid valve group is output to the oil outlet of the solenoid valve group through the electro-proportional pressure reducing valve and the second check valve.

[0016] When the electro-proportional pressure reducing valve's electromagnet is de-energized, the electro-proportional pressure reducing valve is in the second working position, and the working oil port of the electro-proportional pressure reducing valve is connected to the return oil port. The oil outlet of the solenoid valve assembly is connected to the return oil port of the solenoid valve assembly through the first check valve and the electro-proportional pressure reducing valve.

[0017] In some embodiments, the system further includes a main pump assembly, a main valve boom coupling, an explosion-proof valve, and a boom cylinder;

[0018] The oil outlet of the main pump assembly is connected to the oil inlet of the main valve boom;

[0019] The large chamber oil port of the boom cylinder is connected to the second port of the explosion-proof valve;

[0020] The main valve boom assembly has a first pilot pressure port, a second pilot pressure port, a second working port connected to the first port of the explosion-proof valve, and a first working port connected to the small chamber port of the boom cylinder.

[0021] When the first pilot pressure port receives pilot pressure oil, the valve core is pushed to the first working position, the main valve stick connection oil inlet is connected to the first working oil port, and the second working oil port is connected to the main valve stick connection oil port; at this time, the first working oil port outputs hydraulic oil, and the small chamber oil port of the stick cylinder receives oil, realizing the stick retraction action.

[0022] When the second pilot pressure port receives pilot pressure oil, the valve core is pushed to the second working position, the main valve boom inlet is connected to the second working port, and the first working port is connected to the main valve boom return port; at this time, the second working port outputs hydraulic oil to the first port of the explosion-proof valve and then through the second port, and the boom cylinder large chamber oil port receives oil, realizing the boom outward swing action.

[0023] In some embodiments, the system further includes a handle assembly comprising:

[0024] The first pilot handle is used to provide pilot pressure oil to the first pilot pressure port of the main valve boom linkage when it is operated.

[0025] The second pilot handle is used to supply pilot pressure oil to the second pilot pressure port of the main valve boom linkage when it is operated.

[0026] In some embodiments, the explosion-proof valve includes a two-way cartridge valve and a three-position pilot valve, wherein the third port of the explosion-proof valve is connected to the control terminal of the three-position pilot valve 3 for controlling the operating position of the three-position pilot valve.

[0027] In its natural state, the three-position pilot valve is in the second working position, and the two-way cartridge valve can only input oil from the first port and output oil from the second port, and is cut off in the reverse direction.

[0028] When pilot pressure oil is introduced into the third port of the explosion-proof valve, the three-position pilot valve is pushed to the first working position, at which point the oil can flow from the second port to the first port.

[0029] In some embodiments, the system further includes a pressure sensor for detecting the pilot pressure required for the boom retraction action and connected to a controller signal.

[0030] Secondly, a control method for a hydraulic system of an explosion-proof valve for engineering machinery is provided. Based on the aforementioned hydraulic system of the explosion-proof valve for engineering machinery, the method includes:

[0031] In response to the detection of a stick retraction action, the pilot pressure detected by the pressure sensor is converted into a current signal and transmitted to the electro-proportional pressure reducing valve electro-pressure ...

[0032] In some embodiments, the hydraulic system control method for explosion-proof valves in engineering machinery further includes:

[0033] When the construction machinery is shut down for a period of time after operation, the electro-proportional pressure reducing valve's electromagnet is de-energized. Due to the presence of the first check valve in the solenoid valve assembly, there is pilot pressure oil with a first set pressure in the pipeline between the third port of the explosion-proof valve and the solenoid valve assembly. If a stick retraction action is detected at this time, the controller outputs an opening current value to the electro-proportional pressure reducing valve's electromagnet, causing the pilot pressure oil output from the outlet of the solenoid valve assembly to quickly establish the explosion-proof valve's opening pressure.

[0034] Thirdly, a hydraulic system for explosion-proof valves in engineering machinery is provided, wherein the controller includes a processor and a storage medium;

[0035] The storage medium is used to store instructions;

[0036] The processor is configured to operate according to the instructions to execute the method.

[0037] Fourthly, an engineering machinery is provided, which is equipped with the aforementioned engineering machinery explosion-proof valve hydraulic system.

[0038] Compared with the prior art, the beneficial effects achieved by this application are as follows: By setting up a solenoid valve group and controller, using a combination of an electro-proportional pressure reducing valve and a two-way check valve and placing it near the handle, and combining it with the control logic of the controller, this application solves the problem of delayed boom retraction caused by oil backflow and pressure loss. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the hydraulic system of the explosion-proof valve for engineering machinery according to an embodiment of this application;

[0041] The reference numerals in the attached drawings are explained as follows: 1. Handle assembly; 2. Solenoid valve group; 3. Main pump assembly; 4. Main valve boom coupling; 5. Explosion-proof valve; 6. Boom cylinder; 7. Hydraulic oil tank; 8. Controller; 11. First pilot handle; 12. Second pilot handle; A1. First oil outlet of handle; A2. Second oil outlet of handle; 21. Two-way check valve; 211. First check valve; 212. Second check valve; 22. Electro-proportional pressure reducing valve; P2. Inlet of solenoid valve group 2; B2. Outlet of solenoid valve group 2; T2. Return of solenoid valve group 2; 31. Main pump; 32. Main relief valve; C1. First pilot pressure port; C2. Second pilot pressure port; C4. First working port; C3. Second working port; P. Main pump outlet; T. Main pump return port; S. Main pump suction port; 51. Two-way cartridge valve; 52. Relief valve; 53. Three-position pilot valve. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use.

[0043] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to explain the relative positional relationship and movement between components in a specific orientation. If the specific orientation changes, the directional indication will also change accordingly. These terms are used only for the convenience of describing this application and for simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] This application mainly uses the boom cylinder as an example for analysis. The boom of construction machinery is often in a downward position. When the boom needs to retract, the pressure oil from the main valve needs to enter from the small chamber of the boom and return from the large chamber. At this time, the pilot pressure oil circuit of the boom explosion-proof valve needs to supply pilot pressure oil so that the logic check valve in the explosion-proof valve can open in reverse.

[0047] Example 1: This application provides a hydraulic system for an explosion-proof valve of engineering machinery, including a controller. The controller includes a processor and a storage medium. The storage medium is used to store instructions. The processor is used to operate according to the instructions to execute the following control method for the hydraulic system for an explosion-proof valve of engineering machinery.

[0048] like Figure 1 As shown, the hydraulic system of the explosion-proof valve for construction machinery includes a handle assembly 1, a solenoid valve group 2, a main pump assembly 3, a main valve boom link 4, an explosion-proof valve 5, a boom cylinder 6, a hydraulic oil tank 7, and a controller 8;

[0049] A pressure sensor is used to detect the pilot pressure required for the boom retraction action and is connected to the controller signal;

[0050] The solenoid valve assembly 2 includes a bidirectional check valve 21 and an electro-proportional pressure reducing valve 22; wherein the bidirectional check valve 21 includes:

[0051] The first one-way valve 211 is unidirectionally connected to the oil outlet B1 of the solenoid valve assembly 2 and the working oil port of the electro-proportional pressure reducing valve 22, and has a first set pressure a.

[0052] The second check valve 212 is unidirectionally connected to the working port of the electro-proportional pressure reducing valve 22 and the outlet port B1 of the solenoid valve group 2, and has a second set pressure b, which is less than the first set pressure a.

[0053] The controller 8 is connected to the electromagnet Y1 of the electro-proportional pressure reducing valve 22 and is used to control the electromagnet Y1 of the electro-proportional pressure reducing valve 22 to be energized or de-energized, thereby switching the solenoid valve group 2 between the first working state and the second working state.

[0054] In the first working state, the electromagnet Y1 is energized, and the electro-proportional pressure reducing valve 22 is in the first working position (right position). The pilot pressure oil is output through the electro-proportional pressure reducing valve 22 and the second one-way valve 212 to the third port D3 of the explosion-proof valve 5, so that the oil in the explosion-proof valve 5 can flow from the second port D2 to the first port D1, and the stick retraction action is completed.

[0055] In the second working state, the electromagnet Y1 is de-energized, the electro-proportional pressure reducing valve 22 is in the second working position (left position), the pilot pressure oil of the third port D3 of the explosion-proof valve 5 returns through the first check valve 211 and the electro-proportional pressure reducing valve 22, and the first port D1 of the explosion-proof valve 5 is unidirectionally connected to the second port D2.

[0056] It should be noted that, in the second working state, due to the presence of the first check valve 211, there is pilot pressure oil with a first set pressure in the pipeline between the third port D3 of the explosion-proof valve 5 and the solenoid valve group 2.

[0057] In some embodiments, the solenoid valve assembly 2 is further provided with an oil inlet P2 and an oil return port T2;

[0058] When the electromagnet Y1 of the electro-proportional pressure reducing valve 22 is energized, the electro-proportional pressure reducing valve 22 is in the first working position (right position), the oil inlet of the electro-proportional pressure reducing valve 22 is connected to the working oil port, and the pilot pressure oil of the oil inlet P2 of the solenoid valve group 2 is output to the oil outlet B1 of the solenoid valve group 2 through the electro-proportional pressure reducing valve 22 and the second check valve 212.

[0059] When the electromagnet Y1 of the electro-proportional pressure reducing valve 22 is de-energized, the electro-proportional pressure reducing valve 22 is in the second working position (left position), the working oil port of the electro-proportional pressure reducing valve 22 is connected to the return oil port, and the oil outlet B1 of the solenoid valve group 2 is connected to the return oil port T2 of the solenoid valve group 2 through the first check valve 211 and the electro-proportional pressure reducing valve 22.

[0060] In this embodiment, the solenoid valve assembly 2 is located away from the explosion-proof valve 5 and close to the handle assembly 1. It should be noted that the oil inlet P2 is normally energized with pilot pressure oil. When the electro-proportional pressure reducing valve 22's electromagnet Y1 is energized, the pilot pressure oil in the oil inlet P2 will be output to the oil outlet B1 through the one-way valve 212. The greater the current, the greater the output pilot pressure. The first one-way valve 211 can ensure that the intermediate pipeline from the oil outlet B1 to the third port D3 of the explosion-proof valve 5 can maintain the pilot pressure oil at the first set pressure a. The second set pressure b set by the second one-way valve 212 is very small and only serves as a one-way flow control.

[0061] In some embodiments, the oil outlet of the main pump assembly 3 is connected to the oil inlet of the main valve boom link 4;

[0062] The oil port A of the main chamber of the boom cylinder 6 is connected to the second port D2 of the explosion-proof valve 5;

[0063] The main valve boom link 4 has a first pilot pressure port C1, a second pilot pressure port C2, a second working port C3 connected to the first port D1 of the explosion-proof valve 5, and a first working port C4 connected to the small chamber port B of the boom cylinder 6.

[0064] When the first pilot pressure port C1 receives pilot pressure oil, the valve core is pushed to the first working position (left position). The oil inlet of the main valve boom link 4 is connected to the first working port C4, and the second working port C3 is connected to the oil return port of the main valve boom link 4. At this time, the first working port C4 outputs hydraulic oil, and the oil inlet B of the small chamber of the boom cylinder 6 is inlet, realizing the boom retraction action.

[0065] When the second pilot pressure port C2 receives pilot pressure oil, the valve core is pushed to the second working position (right position). The oil inlet of the main valve boom link 4 is connected to the second working port C3, and the first working port C4 is connected to the return port of the main valve boom link 4. At this time, the second working port C3 outputs hydraulic oil to the first port D1 of the explosion-proof valve 5 and then through the second port D2. Oil enters the large chamber port A of the boom cylinder 6, realizing the outward swing of the boom.

[0066] In some embodiments, the handle assembly 1 includes:

[0067] The first pilot handle 11 is used to provide pilot pressure oil to the first pilot pressure port C1 of the main valve boom linkage 4 when it is operated;

[0068] The second pilot handle 12 is used to supply pilot pressure oil to the second pilot pressure port C2 of the main valve boom linkage 4 when it is operated.

[0069] The handle assembly 1 is used to operate the first pilot handle 11 or the second pilot handle 12, so that the valve core of the main valve boom link 4 moves to the first working position and the second working position, and supplies oil to the small chamber oil port B of the boom cylinder 6 through the first working oil port C4 of the main valve boom link 4 or to the large chamber oil port A of the boom cylinder 6 through the second working oil port C3 of the main valve boom link 4.

[0070] In some embodiments, the main pump assembly 3 includes a main pump 31 and a main relief valve 32, having a main pump outlet P, a main pump return port T, and a main pump suction port S; the main pump outlet P is connected to the inlet of the main valve boom connector 4 for outputting hydraulic oil to the system, and the main pump suction port S and the main pump return port T are respectively connected to the hydraulic oil tank 7; one end of the main relief valve 32 is connected to the main pump outlet P, and the other end is connected to the main pump return port T.

[0071] In some embodiments, the explosion-proof valve 5 includes a two-way cartridge valve 51 and a three-position pilot valve 53. The third port D3 of the explosion-proof valve 5 is connected to the control terminal of the three-position pilot valve 53 to control the operating position of the three-position pilot valve 53.

[0072] In its natural state, the three-position pilot valve 53 is in the second working position (rightmost position), and the oil in the two-way cartridge valve 51 can only be input from the first port D1 and output from the second port D2, and is cut off in the reverse direction.

[0073] When pilot pressure oil is introduced into the third port D3 of the explosion-proof valve 5, the three-position pilot valve 53 is pushed to the first working position (leftmost position), at which time the oil can flow from the second port D2 to the first port D1.

[0074] Furthermore, the explosion-proof valve 5 also includes an overflow valve 52, one end of which is connected to the second port D2 of the explosion-proof valve 5, and the other end is connected to the oil return port.

[0075] The working oil ports of the boom cylinder 6 are large chamber oil port A and small chamber oil port B. Oil enters the boom through the large chamber oil port A and swings it outward, while oil enters the boom through the small chamber oil port B and retracts it inward.

[0076] The controller 8 is used to acquire the stick retraction action signal and convert the pilot pressure detected by the pressure sensor into a current signal and transmit it to the electromagnet Y1 of the electro-proportional pressure reducing valve 22 of the solenoid valve group 2. The larger the current input to the electromagnet Y1, the larger the pilot pressure output by the electro-proportional pressure reducing valve 22.

[0077] Example 2: This application also provides a control method for a hydraulic system of an explosion-proof valve for engineering machinery, based on the hydraulic system of the explosion-proof valve for engineering machinery described in Example 1, the method comprising:

[0078] In response to the detection of a stick retraction action, the pilot pressure detected by the pressure sensor is converted into a current signal and transmitted to the electromagnet Y1 of the electro-proportional pressure reducing valve 22. The pilot pressure oil output by the electro-proportional pressure reducing valve 22 passes through the second check valve 212 and is output from the oil outlet B1 of the solenoid valve group 2 to the third port D3 of the explosion-proof valve 5. The pilot pressure oil input to the third port D3 controls the three-position pilot valve 53 of the explosion-proof valve 5 to switch to the first working position, so that the oil in the explosion-proof valve 5 can flow from the second port D2 to the first port D1, completing the stick retraction action.

[0079] It should be noted that when there is a need for the stick to retract, the operation of the first pilot handle 11 causes the first oil outlet A1 of the handle to output pilot pressure oil. The pilot pressure oil output from the first oil outlet A1 of the handle acts on the first pilot pressure oil port C1 of the main valve stick linkage 4. At this time, the valve core of the main valve stick linkage 4 is pushed to the first working position (left position). The hydraulic oil output by the main pump enters the small chamber oil port B of the stick cylinder 6 through the first working oil port C4 of the main valve stick linkage 4.

[0080] In some embodiments, the method further includes:

[0081] When the construction machinery is shut down for a period of time after construction work, the electro-proportional pressure reducing valve 22's electromagnet Y1 is de-energized. Due to the presence of the first check valve 211 of the solenoid valve group 2, there is pilot pressure oil with a first set pressure in the pipeline between the third port D3 of the explosion-proof valve 5 and the solenoid valve group 2. If a stick retraction action is detected at this time, the controller outputs an opening current value to the electromagnet Y1 of the electro-proportional pressure reducing valve 22, so that the pilot pressure oil output from the oil outlet B1 of the solenoid valve group 2 quickly establishes the explosion-proof valve opening pressure.

[0082] Due to the presence of the first check valve 211 in the solenoid valve assembly 2, there is pilot pressure oil with a first set pressure in the pipeline between the third port D3 of the explosion-proof valve 5 and the solenoid valve assembly 2. This technical solution solves the problem of refilling caused by the pilot pressure oil at the third port D3 of the explosion-proof valve 5 completely flowing back into the oil tank. When the boom retraction action is needed again, regardless of the actual pilot pressure during boom action, the controller 8 will output the maximum current value to the solenoid valve assembly 2 as long as it detects the boom retraction action signal. This will cause the pilot pressure oil output from the oil outlet B1 of the solenoid valve assembly 2 to quickly build up the opening pressure of the explosion-proof valve, thus solving the problem of boom retraction delay caused by oil backflow and pressure loss. This control method is more effective when the handle opening is small and when the oil temperature is low.

[0083] Example 3: Based on Examples 1 and 2, this application provides a hydraulic system for an explosion-proof valve of engineering machinery, wherein the controller includes a processor and a storage medium;

[0084] The storage medium is used to store instructions;

[0085] The processor is configured to operate according to the instructions to execute the method.

[0086] Example 4: This application provides an engineering machinery equipped with the aforementioned engineering machinery explosion-proof valve hydraulic system.

[0087] In this embodiment, the engineering machinery can be a material handling machine.

[0088] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0089] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0090] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0091] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0092] The above description is only a preferred embodiment of this application. It should be noted that those skilled in the art should understand that various changes and improvements may be made to this application without departing from the principles and spirit. These improvements should also be considered within the scope of protection of this application and are not limited to the above embodiments.

Claims

1. An hydraulic system for an explosion relief valve of a construction machine, characterized in that, Includes solenoid valve assemblies, explosion-proof valves, and controllers; The solenoid valve assembly includes a bidirectional check valve and an electro-proportional pressure reducing valve; wherein the bidirectional check valve includes: a first check valve, which unidirectionally connects the oil outlet of the solenoid valve assembly to the working oil port of the electro-proportional pressure reducing valve, and has a first set pressure; and a second check valve, which unidirectionally connects the working oil port of the electro-proportional pressure reducing valve to the oil outlet of the solenoid valve assembly, and has a second set pressure, the second set pressure being less than the first set pressure. The controller is connected to the electro-proportional pressure reducing valve via a signal connection to control the energization or de-energization of the electro-proportional pressure reducing valve's electro-proportional pressure reducing valve, thereby switching the solenoid valve assembly between a first operating state and a second operating state. In the first operating state, the electro-proportional pressure reducing valve is energized, and the electro-proportional pressure reducing valve is in the first operating position. Pilot pressure oil is output through the electro-proportional pressure reducing valve and the second check valve to the third port of the explosion-proof valve, allowing the oil in the explosion-proof valve to flow from the second port to the first port, completing the boom retraction action. In the second operating state, the electro-proportional pressure reducing valve is de-energized, and the electro-proportional pressure reducing valve is in the second operating position. The pilot pressure oil at the third port of the explosion-proof valve returns through the first check valve and the electro-proportional pressure reducing valve, and the first port of the explosion-proof valve is unidirectionally open to the second port. It also includes a main pump assembly, a main valve boom coupling, an explosion-proof valve, and a boom cylinder; the oil outlet of the main pump assembly is connected to the oil inlet of the main valve boom coupling; the large chamber oil port of the boom cylinder is connected to the second port of the explosion-proof valve; the main valve boom coupling has a first pilot pressure oil port, a second pilot pressure oil port, a second working oil port connected to the first port of the explosion-proof valve, and a first working oil port connected to the small chamber oil port of the boom cylinder; When the first pilot pressure port receives pilot pressure oil, the valve core is pushed to the first working position, the main valve stick connection oil inlet is connected to the first working oil port, and the second working oil port is connected to the main valve stick connection oil port; at this time, the first working oil port outputs hydraulic oil, and the small chamber oil port of the stick cylinder receives oil, realizing the stick retraction action. When the second pilot pressure port receives pilot pressure oil, the valve core is pushed to the second working position, the main valve boom inlet is connected to the second working port, and the first working port is connected to the main valve boom return port; at this time, the second working port outputs hydraulic oil to the first port of the explosion-proof valve and then through the second port, and the boom cylinder large chamber oil port receives oil, realizing the boom outward swing action.

2. The system according to claim 1, characterized in that, The solenoid valve assembly is also provided with an oil inlet and an oil return port; When the electro-proportional pressure reducing valve is energized, the electro-proportional pressure reducing valve is in the first working position, the oil inlet of the electro-proportional pressure reducing valve is connected to the working oil port, and the pilot pressure oil of the oil inlet of the solenoid valve group is output to the oil outlet of the solenoid valve group through the electro-proportional pressure reducing valve and the second check valve. When the electro-proportional pressure reducing valve's electromagnet is de-energized, the electro-proportional pressure reducing valve is in the second working position, and the working oil port of the electro-proportional pressure reducing valve is connected to the return oil port. The oil outlet of the solenoid valve assembly is connected to the return oil port of the solenoid valve assembly through the first check valve and the electro-proportional pressure reducing valve.

3. The system according to claim 1, characterized in that, It also includes a handle assembly, the handle assembly comprising: The first pilot handle is used to provide pilot pressure oil to the first pilot pressure port of the main valve boom linkage when it is operated. The second pilot handle is used to supply pilot pressure oil to the second pilot pressure port of the main valve boom linkage when it is operated.

4. The system according to claim 1, characterized in that, The explosion-proof valve includes a two-way cartridge valve and a three-position pilot valve. The third port of the explosion-proof valve is connected to the control terminal of the three-position pilot valve to control the working position of the three-position pilot valve. In its natural state, the three-position pilot valve is in the second working position, and the two-way cartridge valve can only input oil from the first port and output oil from the second port, and is cut off in the reverse direction. When pilot pressure oil is introduced into the third port of the explosion-proof valve, the three-position pilot valve is pushed to the first working position, at which point the oil can flow from the second port to the first port.

5. The system according to claim 1, characterized in that, Also includes: A pressure sensor is used to detect the pilot pressure required for the boom retraction action and is connected to the controller signal.

6. A control method for a hydraulic system of an explosion-proof valve for engineering machinery, characterized in that, Based on the hydraulic system for explosion-proof valves of engineering machinery according to any one of claims 1 to 5, the method includes: In response to the detection of a stick retraction action, the pilot pressure detected by the pressure sensor is converted into a current signal and transmitted to the electro-proportional pressure reducing valve ...

7. The control method for the hydraulic system of the explosion-proof valve for engineering machinery according to claim 6, characterized in that, Also includes: When the construction machinery is shut down for a period of time after operation, the electro-proportional pressure reducing valve's electromagnet is de-energized. Due to the presence of the first check valve in the solenoid valve assembly, there is pilot pressure oil with a first set pressure in the pipeline between the third port of the explosion-proof valve and the solenoid valve assembly. If a stick retraction action is detected at this time, the controller outputs an opening current value to the electro-proportional pressure reducing valve's electromagnet, causing the pilot pressure oil output from the outlet of the solenoid valve assembly to quickly establish the explosion-proof valve's opening pressure.

8. The hydraulic system for explosion-proof valves in engineering machinery according to claim 1, characterized in that, The controller includes a processor and a storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the method according to claim 6 or 7.

9. An engineering machinery, characterized in that, The hydraulic system for engineering machinery is equipped with the explosion-proof valve as described in any one of claims 1 to 5 or claim 8.

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