Suspension oil cylinder hydraulic control system and method

Abstract

The present invention discloses a suspension cylinder hydraulic control system and method in the field of suspension cylinder control technology, comprising a suspension cylinder; a balancing valve, wherein the load oil port of the balancing valve is connected to the rodless chamber oil port of the suspension cylinder; a multi-way valve group, wherein the multi-way valve group comprises a reversing valve, wherein a first main oil circuit is connected between the first working oil port of the reversing valve and the oil source port of the balancing valve, and a second main oil circuit is connected between the second working oil port and the rod chamber oil port; a suspension control valve group, wherein the suspension control valve group comprises a hydraulically controlled one-way valve and an unloading valve, wherein the hydraulically controlled one-way valve is arranged on the first main oil circuit, and the pilot control oil circuit of the hydraulically controlled one-way valve is connected to the second main oil circuit; the working oil port of the unloading valve is connected to the first main oil circuit between the balancing valve and the hydraulically controlled one-way valve, and the return oil port is connected to the oil tank. The present invention adopts a combination of back pressure maintenance and flow blocking and pressure maintenance to achieve dual safety guarantees for the hydraulic control system, enhance the safety of load holding, improve operating efficiency, and reduce system energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of suspension oil cylinder control, and in particular to a suspension oil cylinder hydraulic control system and method. Background Art

[0002] For engineering vehicles with wheeled travel supports, such as U-shaped slag tankers, their suspension cylinders are generally responsible for adjusting the height of the suspension frame or performing other functions such as body leveling. In many applications, the relative motion of the suspension cylinder's lifting and lowering motion and the connecting pipeline to the oil circuit requires a hose connection to the cylinder outlet. However, the protective layer of the hose, made of natural rubber or synthetic polymer materials, will age and crack over time under the influence of ultraviolet light and oxygen. Water will penetrate and corrode the pressure-bearing steel wire mesh, resulting in a decrease in the hose's pressure resistance. Even metal pipes, although not showing signs of aging, can be damaged by fatigue or other collisions. If the pipe connected to the suspension cylinder outlet bursts, the load will fall uncontrollably, with serious consequences in many cases.

[0003] In order to prevent the load from falling due to pipe bursting, the outlet of the suspension cylinder is generally equipped with a balance valve, a hydraulic lock, or a double-line explosion-proof valve. When the pipe bursts, the outlet of the suspension cylinder can be quickly closed to maintain the load or safely lower the load.

[0004] However, in actual production activities, hydraulic locks or balancing valves are generally used to maintain the pressure of the hydraulic suspension support control system of the U-shaped slag tank truck. The pressure maintaining structure is a combination of balancing valve + Y-type reversing valve, such as Figure 7 As shown, in the load holding stage, by switching the reversing valve to the middle position, the Y-type middle position is used to make the oil circuit have a lower back pressure, so that the balance valve can be locked, and the occurrence of cylinder blocking can be effectively prevented, so that the balance valve has a stable opening pressure, so that the two suspension cylinders have a high degree of descending synchronization; however, in actual production activities, this pressure holding structure will still cause a small amount of load holding function failure (referred to as load failure).

[0005] As a special metallurgical transport vehicle, the suspension support of the U-shaped slag tank car is responsible for the transfer and transportation of high-temperature slag tanks. It has high requirements for load safety and does not allow phenomena such as load failure to occur. Therefore, how to further reduce or eliminate the occurrence of load failure is a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the Invention

[0006] In view of this, an object of the present invention is to provide a suspension cylinder hydraulic control system to solve the technical problem of load failure in existing hydraulic control systems.

[0007] The technical solution adopted by the present invention is: a suspension cylinder hydraulic control system for achieving the lifting, lowering and holding of the suspension frame; the system includes:

[0008] A suspension oil cylinder, wherein the suspension oil cylinder is provided with a rodless chamber oil port and a rod chamber oil port;

[0009] A balancing valve, wherein the balancing valve is provided with a load oil port and an oil source oil port, wherein the load oil port is communicated with the rodless chamber oil port;

[0010] A multi-way valve assembly, the multi-way valve assembly including a reversing valve, the reversing valve having a first working oil port and a second working oil port, a first main oil circuit being connected between the first working oil port and the oil source port, and a second main oil circuit being connected between the second working oil port and the rod chamber oil port;

[0011] A suspension control valve group, the suspension control valve group includes a hydraulically controlled one-way valve and an unloading valve, the hydraulically controlled one-way valve is arranged in the first main oil circuit, and is used for the oil inlet circulation of the first main oil circuit, and the pilot control oil circuit of the hydraulically controlled one-way valve is connected with the second main oil circuit, and is used for the return oil circulation of the first main oil circuit; the working oil port of the unloading valve is connected with the first main oil circuit between the balancing valve and the hydraulically controlled one-way valve, and the return oil port is connected with the oil tank, and is used for the delayed timed pressure relief of the suspension cylinder lifting operation and the early pressure relief of the suspension cylinder lowering operation.

[0012] Preferably, the balancing valve is equipped with a built-in safety relief valve, the oil inlet of the safety relief valve is connected to the load oil port of the balancing valve, and the oil return port is connected to the second main oil circuit.

[0013] Preferably, the suspension control valve group further includes a pressure-regulating relief valve, the oil inlet of the pressure-regulating relief valve is connected to the second main oil circuit, and the oil return port is connected to the oil tank.

[0014] Preferably, the suspension control valve group further includes a pilot oil circuit and a pilot lock valve, the pilot oil circuit is connected to the pilot control port of the balancing valve, and the pilot lock valve is arranged on the pilot oil circuit and is used to control the on-off of the pilot oil circuit.

[0015] Preferably, a shuttle valve is provided on the pilot oil circuit, a first oil inlet of the shuttle valve is connected to the first oil source, and a second oil inlet of the shuttle valve is connected to the second oil source.

[0016] Preferably, the suspension control valve group further includes an emergency ball valve, the oil inlet of the emergency ball valve is connected to the oil port of the rodless chamber, and the oil return port is connected to the oil port of the rod chamber.

[0017] Preferably, the oil return port of the unloading valve is provided with a flow limiting damper.

[0018] Preferably, the middle position of the reversing valve is Y-shaped.

[0019] Another object of the present invention is to provide a suspension cylinder hydraulic control method, wherein the method uses the suspension cylinder hydraulic control system described above and comprises the following steps:

[0020] S10: Control the reversing valve to switch from the neutral position to the lifting position, and deliver hydraulic oil to the rodless chamber of the suspension cylinder through the first main oil circuit to perform the lifting operation of the suspension cylinder until it is completed;

[0021] S20: The control reversing valve is switched from the lifting position to the neutral position, and the unloading valve is used to perform delayed timed pressure relief on the first main oil circuit to establish back pressure at the oil source port of the balancing valve. The hydraulically controlled one-way valve on the first main oil circuit is used to block the return flow of hydraulic oil in the first main oil circuit to perform load holding operation on the suspension cylinder.

[0022] S30: Before the load holding operation is completed, the first main oil circuit is depressurized in advance through the unloading valve to eliminate the pressure buildup at the oil source port of the balancing valve.

[0023] S40: The control reversing valve switches from the neutral position to the descending position. The pilot oil circuit first controls the balancing valve to open in the reverse direction. Then, the second main oil circuit supplies hydraulic oil to the rod chamber of the suspension cylinder. The hydraulically controlled one-way valve on the first main oil circuit is controlled to open in the reverse direction to continue the descending operation of the suspension cylinder until it is completed.

[0024] S50: The control reversing valve switches from the descending position to the middle position, and the first main oil circuit is delayed in pressure relief through the unloading valve.

[0025] Preferably, the delay time of the delayed timed pressure relief is 1s to 3s, the timing time of the delayed timed pressure relief is 2s to 4s, the advance time of the early pressure relief is 0.2s to 0.4s, and the delay time of the delayed pressure relief is 2s to 4s.

[0026] Beneficial effects of the present invention:

[0027] After derrick hoists and puts in place, stamp fixedly derrick of derrick pin, make hydraulic oil lead to the base hydraulic oil cylinder, hoist that base puts in place and fixing with same control mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1This is a schematic structural diagram of the suspension cylinder hydraulic control system of the present invention;

[0029] Figure 2 It is a structural diagram of the multi-way valve group;

[0030] Figure 3 It is a structural diagram of the suspension control valve group;

[0031] Figure 4 This is a schematic diagram of the connection between the suspension cylinder and the balance valve;

[0032] Figure 5 This is the hydraulic oil path diagram when the suspension cylinder is performing lifting operations;

[0033] Figure 6 This is the hydraulic oil path diagram when the balancing valve is reversely opened and pressure is released;

[0034] Figure 7 This is a schematic diagram of the structure of the existing suspension cylinder hydraulic control system.

[0035] Description of reference numerals in the figures:

[0036] 100. Suspension cylinder;

[0037] 200, balancing valve;

[0038] 210. Safety relief valve;

[0039] 300, multi-way valve group;

[0040] 310, reversing valve; 320, pressure compensation valve; 330, electronic control drive module;

[0041] 400, suspension control valve group;

[0042] 410, hydraulically controlled check valve; 420, unloading valve; 430, pressure regulating relief valve; 440, pilot lock valve; 450, shuttle valve; 460, emergency ball valve; 470, pilot oil circuit;

[0043] 500, first main oil circuit;

[0044] 600, second main oil circuit;

[0045] 700, fuel tank;

[0046] 800, the first oil source;

[0047] 900. Second oil source. DETAILED DESCRIPTION

[0048] The following is a further detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, and are not intended to limit the present invention.

[0049] In the description of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0051] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0052] After a long period of research, the inventors discovered that after the hydraulic control system of the suspension cylinder of the U-shaped slag tank truck has been used for a period of time, the balance valve or hydraulic lock will have internal leakage due to the sealing of the balance valve or hydraulic lock itself or the jamming of the valve core. However, the existing hydraulic control system uses the middle position of the Y-type reversing valve to maintain back pressure. Since the back pressure maintenance cannot block the flow of hydraulic oil, and the flow of hydraulic oil will destroy the back pressure environment in the oil circuit, after the balance valve leaks internally, the suspension cylinder will lose its load holding function.

[0053] Examples, such as Figures 1-6 As shown, a suspension cylinder hydraulic control system is applied to a U-shaped slag tank truck, which can realize the lifting, lowering and holding of the suspension frame; the system includes:

[0054] The suspension oil cylinder 100 is provided with a rodless chamber oil port and a rod chamber oil port.

[0055] The balancing valve 200 is provided with a load oil port and an oil source oil port, and the load oil port is communicated with the rodless chamber oil port.

[0056] The multi-way valve group 300 includes a reversing valve 310, which is provided with a first working oil port and a second working oil port; a first main oil circuit 500 is connected between the first working oil port and the oil source port, and the first main oil circuit 500 is used for the oil inlet and oil return of the rodless chamber of the suspension cylinder 100; a second main oil circuit 600 is connected between the second working oil port and the rod chamber oil port, and the second main oil circuit 600 is used for the oil inlet and oil return of the rod chamber of the suspension cylinder 100.

[0057] The suspension control valve group 400 includes a hydraulically controlled one-way valve 410 and an unloading valve 420. The hydraulically controlled one-way valve 410 is arranged on the first main oil circuit 500 and is used for the oil inlet circulation in the first main oil circuit 500. The pilot control oil circuit of the hydraulically controlled one-way valve 410 is connected to the second main oil circuit 600 and is used for the return oil circulation in the first main oil circuit 500. The working oil port of the unloading valve 420 is connected to the first main oil circuit 500 between the balancing valve 200 and the hydraulically controlled one-way valve 410, and the return oil port is connected to the oil tank 700, which is used for the delayed timed pressure relief of the lifting operation of the suspension cylinder 100 and the early pressure relief of the lowering operation of the suspension cylinder 100.

[0058] It should be noted that the delayed timed pressure relief in this embodiment means: after the lifting operation of the suspension cylinder 100 is completed, pressure relief is performed for a period of time; early pressure relief means: before the suspension cylinder 100 descends, pressure relief is performed for a period of time in advance.

[0059] The present application adopts a method that combines blocking flow, back pressure maintenance and timed pressure relief. First, a hydraulically controlled one-way valve 410 is provided on the first main oil circuit 500 connected to the rodless chamber of the suspension cylinder 100. The hydraulically controlled one-way valve 410 acts on the one-way flow of hydraulic oil in the first main oil circuit 500, thereby blocking the reverse flow of hydraulic oil in the first main oil circuit 500, preventing the occurrence of internal leakage of the balance valve 200, and further preventing the occurrence of load failure. Then, the unloading valve 420 is connected to the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the balance valve 200. The unloading valve 420 can be used to timedly relieve the pressure of the first main oil circuit 500, thereby establishing a lower back pressure in the first main oil circuit 500 between the balance valve 200 and the hydraulically controlled one-way valve 410, which not only enables the balance valve 200 to be locked, but also prevents the first main oil circuit 500 from being blocked, and ensures that the balance valve 200 has a stable opening pressure, thereby improving the synchronization of the descent of the two suspension cylinders 100.

[0060] In one embodiment, Figure 1 、 Figure 3 、 Figure 4As shown, the balancing valve 200 has a built-in safety relief valve 210 to mitigate impacts on the suspension cylinder 100. The oil inlet of the safety relief valve 210 is connected to the load oil port of the balancing valve 200, and the oil return port of the safety relief valve 210 is connected to the second main oil circuit 600, so that the hydraulic oil discharged from the rodless chamber of the suspension cylinder 100 can flow back to the rod chamber of the suspension cylinder 100. This configuration is because: when the vehicle is moving in the load-holding state, the suspension cylinder 100 may be impacted by the ground. This impact can cause the oil pressure in the rodless chamber of the suspension cylinder 100 to rise sharply, which may affect the safety of the hydraulic control system. In this embodiment, the rod chamber oil port and the rodless chamber oil port of the suspension cylinder 100 are connected by the safety overflow valve 210. When the suspension cylinder 100 is impacted, a small amount of hydraulic oil in the rodless chamber of the suspension cylinder 100 can overflow to the rod chamber of the suspension cylinder 100 to maintain the stability of the oil pressure in the rodless chamber of the suspension cylinder 100, thereby reducing the impact of ground impact on the safety of the hydraulic control system.

[0061] In one embodiment, Figure 1 、 Figure 3 As shown, the suspension control valve assembly 400 further includes a pressure regulating relief valve 430, which is disposed on the second main oil circuit 600. The pressure regulating relief valve 430 has an oil inlet connected to the second working oil port of the reversing valve 310 via the second main oil circuit 600, an oil outlet connected to the rod chamber oil port of the suspension cylinder 100 via the second main oil circuit 600, and an oil return port connected to the oil tank 700 via an oil drain passage. The pressure regulating relief valve 430 is used to adjust the maximum oil pressure in the rod chamber of the suspension cylinder 100, thereby adjusting the lowering speed of the suspension cylinder 100. This arrangement is because, during the lowering operation of the suspension cylinder 100, the lowering speed is proportional to the oil pressure in the second main oil circuit 600. That is, the higher the oil pressure in the second main oil circuit 600, the greater the amount of hydraulic oil that enters the rod chamber of the suspension cylinder 100 through the second main oil circuit 600 per unit time, and the faster the lowering speed of the suspension cylinder 100. In this embodiment, a pressure-regulating relief valve 430 is provided on the second main oil circuit 600. The overflow effect of the pressure-regulating relief valve 430 on the second main oil circuit 600 can be used to adjust the oil pressure of the hydraulic oil in the second main oil circuit 600, thereby controlling the amount of hydraulic oil entering the rod chamber of the suspension cylinder 100 per unit time, thereby realizing the adjustment of the lowering speed of the suspension cylinder 100 to better meet the working conditions.

[0062] In a specific embodiment, if Figure 1 、 Figure 3As shown, the oil inlet of the hydraulically controlled one-way valve 410 is connected to the first working oil port A of the reversing valve 310 through the first main oil circuit 500, and the oil outlet is connected to the oil source port of the balancing valve 200 through the first main oil circuit 500, so that the hydraulic oil can flow unidirectionally from the reversing valve 310 to the balancing valve 200, so as to establish back pressure in the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the reversing valve 310.

[0063] In a specific embodiment, if Figure 3 As shown, the suspension control valve group 400 also includes a pilot oil circuit 470 and a pilot lock valve 440. The oil outlet end of the pilot oil circuit 470 is connected to the pilot control port of the balancing valve 200, and is used to deliver pilot oil to the balancing valve 200; the pilot lock valve 440 is arranged on the pilot oil circuit 470, and is used to control the on-off of the pilot oil circuit 470, and then control the reverse opening of the balancing valve 200; the normal position of the pilot lock valve 440 is that the hydraulic oil is normally closed, that is, when the two-position four-way solenoid valve is in the normal position, the pilot oil does not flow in the pilot oil circuit 470. This setting is because: the balancing valve 200 is an internal leakage load-bearing unidirectional type, and its opening pilot pressure is externally controlled. A pilot lock valve 440 is set on the pilot oil circuit 470. The pilot lock valve 440 controls the on-off of the pilot oil circuit 470 to achieve control of the reverse opening of the balancing valve 200. This can prevent the reverse opening of the balancing valve 200 caused by misoperation, and improve the safety of the hydraulic control system for the lifting and lowering operations of the suspension cylinder 100.

[0064] Preferably, the pilot lock valve 440 is a two-position three-way solenoid valve, the working oil port A of the two-position three-way solenoid valve is connected to the pilot control port of the balancing valve 200 through the pilot oil circuit 470, the oil inlet P is connected to the oil source through the pilot oil circuit 470, and the oil return port T is connected to the oil tank 700 through the oil drain channel.

[0065] In a specific embodiment, if Figure 1 As shown, the oil inlet of pilot oil circuit 470 is connected to the oil outlet of shuttle valve 450. The first oil inlet of shuttle valve 450 is connected to the first oil source 800 via a pilot branch, while the second oil inlet is connected to the second oil source 900 via a pilot branch. This allows different pilot oils to be introduced into pilot oil circuit 470 via shuttle valve 450. This arrangement is based on the fact that, in actual production activities, various components of a hydraulic system may fail, leading to failure of the entire hydraulic control system. However, after a hydraulic control system fails, it is not allowed to remain in a load-holding state for a long time. In this embodiment, pilot oil circuit 470 is connected to the first oil source 800 and the second oil source 900 via shuttle valve 450. In the event of a failure of the first oil source 800, pilot oil can be supplied to the counterbalance valve 200 via the second oil source 900, enabling the load to be lowered and improving the reliability of the reverse opening of the counterbalance valve 200.

[0066] Preferably, the first oil source 800 is a variable displacement piston pump, that is, the driving oil source of the suspension cylinder 100, and the second oil source 900 is a parking or other independent oil source.

[0067] In a specific embodiment, if Figure 1 As shown, the oil outlet of pilot oil circuit 470 is connected to two pilot branches, which are connected one-to-one with the pilot control ports of the balancing valves 200 on the two suspension cylinders 100. This arrangement is because connecting pilot oil circuit 470 to the two balancing valves 200 can simultaneously achieve reverse opening of the two balancing valves 200, achieving synchronized operation of the two suspension cylinders 100.

[0068] In other embodiments, two pilot oil circuits 470 may be provided, and the pilot oil circuits 470 are connected to the balancing valves 200 in a one-to-one correspondence to achieve unilateral independent control of the suspension cylinder 100 movement.

[0069] In a specific embodiment, if Figure 1 、 Figure 4 As shown, the suspension control valve group 400 also includes an emergency ball valve 460. The oil inlet of the emergency ball valve 460 is connected to the load oil port, and the oil outlet is connected to the rod chamber oil port. The emergency ball valve 460 is used to return the hydraulic oil in the rodless chamber of the suspension cylinder 100 to the rod chamber in an emergency state, thereby realizing the emergency lowering of the load. This arrangement is because: in actual production activities, various components of the hydraulic system may fail, which in turn causes the entire hydraulic control system to fail. However, after the hydraulic control system fails, it is not allowed to be in a load holding state for a long time. In this embodiment, an emergency ball valve 460 is connected between the rod chamber oil port and the rodless chamber oil port of the suspension cylinder 100. In an emergency state, by opening the emergency ball valve 460, the hydraulic oil in the rodless chamber of the suspension cylinder 100 can be returned to the rod chamber to realize the emergency lowering of the load.

[0070] In a specific embodiment, if Figure 1 、 Figure 3 As shown, the unloading valve 420 is a two-position four-way solenoid valve, and the normal position of the unloading valve 420 is the hydraulic oil normally closed, that is, the hydraulic oil in the first main oil circuit 500 does not flow to the unloading valve 420; the working oil port A and the working oil port B of the two-position four-way solenoid valve are respectively connected to the two first main oil circuits 500 in a one-to-one correspondence, and the oil inlet P and the oil return port T are connected to the oil tank 700 through the oil drain channel, and a back pressure check valve is provided on the oil drain channel to relieve the pressure of the first main oil circuit 500 through the unloading valve 420, and establish back pressure on the first main oil circuit 500 between the hydraulic control check valve 410 and the balancing valve 200; a limiting flow damper is installed at the oil inlet P and the oil return port T of the unloading valve 420 to limit the pressure relief flow rate of the hydraulic oil during pressure relief.

[0071] It should be noted that the oil inlet P of the unloading valve 420 in the present application is used as an oil return port, and the oil inlet P is the name of the oil port on the two-position four-way solenoid valve.

[0072] In a specific embodiment, if Figure 1 、 Figure 2 As shown, the middle position of the reversing valve 310 is Y-shaped. This arrangement is because: when the reversing valve 310 is in the middle position, both the first main oil circuit 500 and the second main oil circuit 600 are connected to the oil tank 700, which can achieve back pressure in the first main oil circuit 500 and the second main oil circuit 600, thereby ensuring the stability of the opening pressure of the balance valve 200; at the same time, it can ensure the reliability of the reverse locking of the hydraulically controlled one-way valve 410, and make the rod chamber of the suspension cylinder 100 communicate with the oil tank 700, ensuring that the suspension cylinder 100 supporting the wheel always maintains contact with the ground when the tank is unloaded, eliminating the phenomenon of the high pressure lifting the rear frame when the tank is lowered to the bottom, causing the tank to hang.

[0073] In a specific embodiment, if Figure 2 As shown, the reversing valve 310 is a hydraulically controlled proportional reversing valve, and the multi-way valve group 300 is a load-sensitive control type multi-way valve group, and includes a pressure compensation valve 320 and an electronically controlled drive module 330. The electronically controlled drive module 330 is connected to the two control ends of the hydraulically controlled electromagnetic reversing valve, and is used to control the reversing valve 310 to switch between the lifting position, the middle position and the lowering position; the oil outlet of the pressure compensation valve 320 is connected to the oil inlet P of the hydraulically controlled electromagnetic reversing valve, and the oil inlet is connected to the oil outlet of the variable piston pump, which is used to pressure compensate the hydraulic oil entering the reversing valve 310; the oil return port T of the hydraulically controlled electromagnetic reversing valve is connected to the oil tank 700.

[0074] In a specific embodiment, if Figure 1 As shown, there are two suspension cylinders 100 and two multi-way valve groups 300 , which are connected to the suspension cylinders 100 in a one-to-one correspondence, and are used to control the independent lifting and lowering of the two suspension cylinders 100 .

[0075] In one embodiment, a suspension cylinder hydraulic control method is provided, wherein the suspension cylinder hydraulic control system is used, and the method comprises the following steps:

[0076] S10: The reversing valve 310 is controlled to switch from the neutral position to the lifting position, and hydraulic oil is delivered to the rodless chamber of the suspension cylinder 100 through the first main oil circuit 500 to perform the lifting operation of the suspension cylinder 100 until it is completed.

[0077] S20: The control reversing valve 310 is switched from the lifting position to the middle position, and the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the balancing valve 200 is first depressurized with a delayed timing through the unloading valve 420 to establish back pressure at the oil source port of the balancing valve 200, and the return oil flow of the hydraulic oil in the first main oil circuit 500 is blocked through the hydraulically controlled one-way valve 410 to perform the load holding operation of the suspension cylinder 100.

[0078] S30 : Before the load holding operation is completed, the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the balancing valve 200 is depressurized in advance through the unloading valve 420 to eliminate the pressure buildup at the oil source port of the balancing valve 200 .

[0079] S40: Control the reversing valve 310 to switch from the middle position to the descending position, first control the balance valve 200 to open in the reverse direction through the pilot oil circuit 470, then deliver hydraulic oil to the rod chamber of the suspension cylinder 100 through the second main oil circuit 600, and control the hydraulic control one-way valve 410 on the first main oil circuit 500 to open in the reverse direction, so as to carry out the descending operation of the suspension cylinder 100 until it is completed.

[0080] S50 : The reversing valve 310 is controlled to switch from the descending position to the middle position, and the first main oil circuit 500 is subjected to delayed pressure relief via the unloading valve 420 .

[0081] Specific embodiment 1 is a suspension cylinder hydraulic control method, which uses the suspension cylinder hydraulic control system described above and includes the following steps:

[0082] S10: When the suspension cylinder 100 is lifted, the lifting position of the electronically controlled drive module 330 that controls the multi-way valve group 300 is energized and works. At this time, the pilot oil after being reduced in pressure by the pilot pressure reducing valve controls the reversing valve 310 to switch (the middle position switches to the lifting position). The hydraulic oil from the variable piston pump enters the rodless chamber of the two suspension cylinders 100 through the pressure compensation valve 320, the reversing valve 310, the hydraulically controlled one-way valve 410 and the balancing valve 200, thereby realizing the synchronous lifting action of the two suspension cylinders 100 on the suspension frame.

[0083] Among them, the lifting speed of the two suspension cylinders 100 is controlled by the tilt amplitude of the corresponding electric control handle; the synchronization is maintained by the opening of the reversing valve 310, and the operator can achieve real-time fine-tuning of the opening of the left and right independent electric control handles.

[0084] S20: After the load lifting operation is completed, the lifting position of the electronic control drive module 330 that controls the multi-way valve group 300 is powered off and reset. At this time, under the action of the spring force, the reversing valve 310 is controlled to switch (the lifting position is switched to the middle position). After a delay of 1s to 3s after the electronic control handle is in the middle position, the unloading valve 420 is controlled to be electrically conductive for 2s to 4s, which is used to delay the timed pressure relief of the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the balancing valve 200, so as to establish back pressure in the first main oil circuit 500 between the balancing valve 200 and the hydraulically controlled one-way valve 410, to ensure the accuracy of the reverse opening pressure set for the balancing valve 200 (the pressure at the oil source port of the balancing valve 200 will cause the reverse opening pressure of the balancing valve 200 to increase), and to block the reverse flow of hydraulic oil in the first main oil circuit 500 through the hydraulically controlled one-way valve 410 to perform the load holding operation of the suspension cylinder 100.

[0085] S30: Before the load holding operation is completed, that is, before the suspension cylinder 100 is lowered, the unloading valve 420 is controlled to be energized 0.2s to 0.4s earlier than the electronic control drive module 330, so as to relieve the pressure of the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the balancing valve 200 in advance, so as to eliminate the pressure buildup at the oil source port of the balancing valve 200.

[0086] S40: When the suspension cylinder 100 descends, the lowering position of the electronic control drive module 330 that controls the multi-way valve group 300 is energized and works. At this time, the pilot oil after the pressure reduction by the pilot pressure reducing valve controls the reversing valve 310 to switch (the middle position switches to the lowering position). The pressure oil from the variable piston pump enters the rod chamber of the suspension cylinder 100 through the pressure compensation valve 320 and the reversing valve 310, and at the same time controls the hydraulic control check valve 410 to open in the reverse direction; at the same time, the pilot oil from the shuttle valve 450 enters the pilot lock valve 440 to stand by. When the pilot lock valve 440 is energized, the balance valves 200 on the two suspension cylinders 100 open in the reverse direction. At this time, the hydraulic oil in the rodless chamber of the suspension cylinder 100 flows back through the reverse-opened hydraulic check valve 410, and then flows back to the oil tank 700 through the return oil port T of the reversing valve 310, realizing the overall lowering action of the suspension frame.

[0087] Among them, the maximum pressure of the rod chamber leading to the suspension cylinder 100 can be controlled by adjusting the set pressure of the pressure-regulating relief valve 430 on the second main oil circuit 600, so that the maximum lowering speed of the suspension cylinder 100 can be adjusted, and the lowering speed is positively correlated with the throttle.

[0088] S50: After the lowering operation is completed, the lowering position of the electronically controlled drive module 330 that controls the multi-way valve group 300 is reset after power failure. At this time, under the action of the spring force, the reversing valve 310 is controlled to reverse (the lowering position is switched to the middle position); after controlling the middle position of the electronically controlled handle for a delay of 2s to 4s, the unloading valve 420 is controlled to be reset after power failure, thereby realizing delayed pressure relief of the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the balancing valve 200, which can ensure the reliable operation of the suspension cylinder 100 and the balancing valve 200, and can improve the synchronization accuracy of the lowering speed of the two suspension cylinders 100.

[0089] Compared with the prior art, this application has at least the following beneficial technical effects:

[0090] This application unloads the first main oil circuit 500 between the hydraulically controlled one-way valve 410 and the balancing valve 200 through the unloading valve 420, which can effectively eliminate the cylinder blocking phenomenon, prevent the opening pressure of the balancing valve 200 from being too high, and improve the synchronization of the descent of the two suspension cylinders 100.

[0091] This application overflows the second main oil circuit 600 through the pressure-regulating relief valve 430, which can adjust the maximum pressure of the rod chamber of the suspension cylinder 100, realize the adjustment of the load lowering operation speed, and better meet the working conditions.

[0092] In the present application, the opening pilot pressure of the balancing valve 200 is set to an external control mode, and a pilot lock valve 440 is provided on the pilot oil circuit 470, thereby improving the safety of the lifting and lowering operation of the suspension system.

[0093] The present application can enhance the explosion-proof safety and reliability of the pipeline of the first main oil circuit 500 connected to the suspension cylinder 100 , and improve the synchronization and operating efficiency of the descent of the two suspension cylinders 100 .

[0094] This application adopts a combination of back pressure maintenance and blocking flow maintenance to achieve dual safety guarantees for the hydraulic control system. On the basis of improving safety design, it improves operating efficiency, reduces system energy consumption, and better meets the current industry's technical requirements for engineering vehicles in terms of safety and energy saving.

[0095] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A suspension cylinder hydraulic control system, characterized in that: include: A suspension oil cylinder (100), wherein the suspension oil cylinder (100) is provided with a rodless chamber oil port and a rod chamber oil port; A balancing valve (200), the balancing valve (200) being provided with a load oil port and an oil source oil port, the load oil port being in communication with the rodless chamber oil port; A multi-way valve assembly (300), the multi-way valve assembly (300) comprising a reversing valve (310), the reversing valve (310) being provided with a first working oil port and a second working oil port, a first main oil circuit (500) being connected between the first working oil port and the oil source port, and a second main oil circuit (600) being connected between the second working oil port and the rod chamber oil port; A suspension control valve group (400), comprising a hydraulically controlled one-way valve (410) and an unloading valve (420), wherein the hydraulically controlled one-way valve (410) is arranged on a first main oil circuit (500) and is used for oil inlet circulation of the first main oil circuit (500), and a pilot control oil circuit of the hydraulically controlled one-way valve (410) is connected to a second main oil circuit (600) and is used for controlling oil return circulation of the first main oil circuit (500); a working oil port of the unloading valve (420) is connected to the first main oil circuit (500) between the balancing valve (200) and the hydraulically controlled one-way valve (410), and an oil return port is connected to an oil tank (700), and is used for delayed timed pressure relief during the lifting operation of the suspension cylinder (100) and early pressure relief during the lowering operation of the suspension cylinder (100); The delayed timed pressure relief means that after the lifting operation of the suspension oil cylinder (100) is completed, the pressure relief is performed for a period of time after a delay; the early pressure relief means that before the lowering operation of the suspension oil cylinder (100), the pressure relief is performed for a period of time in advance.

2. A suspension cylinder hydraulic control system according to claim 1, characterized in that: The balancing valve (200) is equipped with a built-in safety relief valve (210), the oil inlet of the safety relief valve (210) is connected to the load oil port of the balancing valve (200), and the oil return port is connected to the second main oil circuit (600).

3. A suspension cylinder hydraulic control system according to claim 1, characterized in that: The suspension control valve group (400) further comprises a pressure regulating relief valve (430), wherein the oil inlet of the pressure regulating relief valve (430) is connected to the second main oil circuit (600), and the oil return port is connected to the oil tank (700).

4. A suspension cylinder hydraulic control system according to claim 1, characterized in that: The suspension control valve group (400) further comprises a pilot oil circuit (470) and a pilot lock valve (440). The pilot oil circuit (470) is connected to the pilot control port of the balancing valve (200). The pilot lock valve (440) is arranged on the pilot oil circuit (470) and is used to control the on / off of the pilot oil circuit (470).

5. A suspension cylinder hydraulic control system according to claim 4, characterized in that: A shuttle valve (450) is provided on the pilot oil circuit (470), wherein a first oil inlet of the shuttle valve (450) is in communication with a first oil source (800), and a second oil inlet is in communication with a second oil source (900).

6. The suspension cylinder hydraulic control system according to claim 1, characterized in that: The suspension control valve group (400) further comprises an emergency ball valve (460), wherein the oil inlet of the emergency ball valve (460) is communicated with the oil port of the rodless chamber, and the oil return port is communicated with the oil port of the rod chamber.

7. The suspension cylinder hydraulic control system according to claim 1, characterized in that: The oil return port of the unloading valve (420) is provided with a flow limiting damper.

8. The suspension cylinder hydraulic control system according to claim 1, characterized in that: The middle position of the reversing valve (310) is Y-shaped.

9. A suspension cylinder hydraulic control method, the method using the suspension cylinder hydraulic control system according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: S10: Control the reversing valve (310) to switch from the neutral position to the lifting position, and deliver hydraulic oil to the rodless chamber of the suspension cylinder (100) through the first main oil circuit (500) to perform the lifting operation of the suspension cylinder (100) until it is completed; S20: Controlling the reversing valve (310) to switch from the lifting position to the neutral position, delaying the timed pressure relief of the first main oil circuit (500) through the unloading valve (420), and blocking the return flow of the hydraulic oil in the first main oil circuit (500) through the hydraulically controlled one-way valve (410) on the first main oil circuit (500), so as to perform the load holding operation of the suspension cylinder (100); S30: Before the load holding operation is completed, the first main oil circuit (500) is depressurized in advance through the unloading valve (420) to eliminate the pressure buildup at the oil source port of the balancing valve (200); S40: Control the reversing valve (310) to switch from the neutral position to the descending position, first control the balancing valve (200) to open in the reverse direction through the pilot oil circuit (470), then deliver hydraulic oil to the rod chamber of the suspension cylinder (100) through the second main oil circuit (600), and control the hydraulic control check valve (410) on the first main oil circuit (500) to open in the reverse direction, so as to carry out the descending operation of the suspension cylinder (100) until it is completed; S50: The reversing valve (310) is controlled to switch from the descending position to the middle position, and the first main oil circuit (500) is subjected to delayed pressure relief via the unloading valve (420).

10. A suspension cylinder hydraulic control method according to claim 9, characterized in that: The delay time of the delayed timed pressure relief is 1s to 3s, the timing time of the delayed timed pressure relief is 2s to 4s, the advance time of the early pressure relief is 0.2s to 0.4s, and the delay time of the delayed pressure relief is 2s to 4s.

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