Hydraulic system of aerial work platform and aerial work platform

Abstract

The present invention belongs to the technical field of aerial work platforms, and discloses a hydraulic system of an aerial work platform and an aerial work platform. The hydraulic system of the aerial work platform includes a power unit, a lifting control valve and a steering control valve. The oil inlet of the power unit is connected to the oil tank; the oil inlet of the lifting control valve is connected to the oil outlet of the power unit, the oil return port of the lifting control valve is connected to the oil tank, and the second working oil port of the lifting control valve is connected to the lifting actuator. The oil inlet of the steering control valve is connected to the first working oil port of the lifting control valve, the oil return port of the steering control valve is connected to the oil tank, the first working oil port of the steering control valve is connected to the rodless chamber of the steering actuator, and the second working oil port of the steering control valve is connected to the rod chamber of the steering actuator. When the lifting control valve is in the middle position, the first working oil port and the second working oil port of the lifting control valve are both connected to the oil return port, and the oil inlet of the steering control valve is connected to the first working oil port of the lifting control valve to avoid pressure build-up.

Description

Technical Field

[0001] The present invention relates to the technical field of aerial work platforms, and in particular to a hydraulic system of an aerial work platform and the aerial work platform. Background Art

[0002] Aerial work platforms are widely used in infrastructure, transportation, prefabricated buildings, etc. They can generally perform actions such as leg extension and retraction, lifting and steering. In the prior art, the hydraulic system of the aerial work platform includes a power unit, a lifting control valve and a steering control valve. The oil inlet of the power unit is connected to the oil tank, and the oil outlet of the power unit is connected to the lifting actuator through the lifting control valve. The oil outlet of the power unit is also connected to the steering actuator through the steering control valve. When the aerial work platform performs a lifting action, the lifting control valve is energized, and the power unit pumps the hydraulic oil to the lifting actuator through the lifting control valve; when the aerial work platform performs a steering action, the steering control valve is energized, and the power unit pumps the hydraulic oil to the steering actuator through the steering control valve. In the above-mentioned hydraulic system, there will be pressure buildup between the steering control valve and the steering actuator. When the steering action is performed, there will be a pressure shock, and long-term pressure buildup may cause malfunction. Summary of the invention

[0003] The purpose of the present invention is to provide a hydraulic system for an aerial work platform and an aerial work platform, which can effectively avoid pressure build-up in the hydraulic system and avoid pressure shock during steering action.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] The hydraulic system of the aerial work platform includes:

[0006] tank;

[0007] A power device, wherein the oil inlet of the power device is connected to the oil tank;

[0008] A lifting control valve, wherein the oil inlet of the lifting control valve is communicated with the oil outlet of the power device, the oil return port of the lifting control valve is communicated with the oil tank, the second working oil port of the lifting control valve is communicated with the lifting actuator, and when the lifting control valve is in the middle position, the first working oil port of the lifting control valve and the second working oil port of the lifting control valve are both communicated with the oil return port of the lifting control valve;

[0009] A steering control valve, wherein the oil inlet of the steering control valve is connected to the first working oil port of the lifting control valve, the oil return port of the steering control valve is connected to the oil tank, the first working oil port of the steering control valve is connected to the rodless chamber of the steering actuator, and the second working oil port of the steering control valve is connected to the rod chamber of the steering actuator.

[0010] As an optional solution, the hydraulic system of the aerial work platform also includes a first overflow valve, a first oil port of the first overflow valve is connected to the first working oil port of the lifting control valve and the oil inlet of the steering control valve, and a second oil port of the first overflow valve is connected to the oil tank.

[0011] As an optional solution, the hydraulic system of the aerial work platform also includes an outrigger control valve, the oil inlet of the outrigger control valve is connected to the oil outlet of the power unit, the oil return port of the outrigger control valve is connected to the oil tank, the first working oil port of the outrigger control valve is connected to the rod chamber of the outrigger group actuator cylinder, and the second working oil port of the outrigger control valve is connected to the rodless chamber of the outrigger group actuator cylinder.

[0012] As an optional solution, the hydraulic system of the aerial work platform also includes a shuttle valve and a second overflow valve, the first working oil port of the outrigger control valve and the second working oil port of the outrigger control valve are also connected to the first oil inlet of the shuttle valve and the second oil inlet of the shuttle valve respectively, the oil outlet of the shuttle valve is connected to the first oil port of the second overflow valve, and the second oil port of the second overflow valve is connected to the oil tank.

[0013] As an optional solution, the hydraulic system of the aerial work platform further includes:

[0014] A floating control valve, wherein the oil inlet of the floating control valve is connected to the oil outlet of the power device, the oil return port of the floating control valve is connected to the oil tank, and the working oil port of the floating control valve is connected to the floating actuator;

[0015] A brake release control valve, wherein the oil inlet of the brake release control valve is connected to the oil outlet of the power device, the oil return port of the brake release control valve is connected to the oil tank, and the working oil port of the brake release control valve is connected to the brake release actuator, the accumulator, and the pressure sensor respectively.

[0016] As an optional solution, it also includes a main control valve, the oil inlet of the main control valve is connected to the oil outlet of the power unit, the working oil port of the main control valve is connected to the oil inlet of the floating control valve and the oil inlet of the brake release control valve, and the oil return port of the main control valve is connected to the oil tank.

[0017] As an optional solution, the hydraulic system of the aerial work platform also includes a one-way valve, which is arranged on the pipeline between the oil outlet of the power unit and the oil inlet of the lift control valve, and the one-way valve is configured to conduct one-way electricity in the direction from the power unit to the lift control valve.

[0018] As an optional solution, the hydraulic system of the aerial work platform also includes a main overflow valve, a first oil port of the main overflow valve is connected to the pipeline between the oil outlet of the power unit and the oil inlet of the lift control valve, and a second oil port of the main overflow valve is connected to the oil tank.

[0019] As an optional solution, the valve cores of the lift control valve and the steering control valve are both sliding valve structures.

[0020] An aerial work platform comprises the hydraulic system of the aerial work platform described in any of the above schemes.

[0021] Beneficial effects of the present invention:

[0022] The present invention provides a hydraulic system for an aerial work platform. When a lifting control valve is in a neutral position, a first working oil port and a second working oil port of the lifting control valve are both connected to an oil return port of the lifting control valve, and an oil inlet of a steering control valve is connected to the first working oil port of the lifting control valve, so that the lifting control valve and the steering control valve cooperate to complete the action of a steering actuator and avoid pressure buildup in the steering actuator, and the lifting control valve can independently complete the action of the lifting actuator and avoid pressure buildup, thereby effectively avoiding the problem of erroneous operation that may be caused by pressure shock and long-term pressure buildup. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of a hydraulic system of an aerial work platform provided in an embodiment of the present invention.

[0024] In the figure:

[0025] 1. Fuel tank; 2. Power unit; 21. Power source; 22. Gear pump; 3. Lifting control valve; 4. Steering control valve; 5. First relief valve; 6. Outrigger control valve; 7. Shuttle valve; 8. Second relief valve; 9. First floating control valve; 10. Second floating control valve; 20. Release brake control valve; 30. Main control valve; 40. Flow valve; 50. Check valve; 60. Main relief valve; 70. Pressure reducing valve; 80. Accumulator. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, it can be a mechanical connection or an electrical connection, it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the description of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0030] like Figure 1 As shown, an embodiment of the present invention provides a hydraulic system for an aerial work platform, which includes a power device 2, a lifting control valve 3 and a steering control valve 4.

[0031] Among them, the oil inlet of the power device 2 is connected to the oil tank 1; the oil inlet of the lifting control valve 3 is connected to the oil outlet of the power device 2, the oil return port of the lifting control valve 3 is connected to the oil tank 1, and the second working oil port of the lifting control valve 3 is connected to the lifting actuator. When the lifting action is performed, the right position of the lifting control valve 3 is energized, and the power device 2 outputs the hydraulic oil in the oil tank 1 to the P port, and then outputs it to the L port through the lifting control valve 3, and then delivers it to the lifting actuator through the L port to complete the lifting action. Further, when the lifting control valve 3 is in the middle position, the second working oil port of the lifting control valve 3 is connected to the oil return port of the lifting control valve 3. When the lifting action is completed, the lifting control valve 3 is in the middle position, the L port is connected to the oil tank 1, and the hydraulic oil in the lifting actuator can pass through the lifting control valve 3 and return to the oil tank 1 through the T port to release the pressure.

[0032] The oil inlet of the steering control valve 4 is connected to the first working oil port of the lifting control valve 3, the oil return port of the steering control valve 4 is connected to the oil tank 1, the first working oil port of the steering control valve 4 is connected to the rodless chamber of the steering actuator, and the second working oil port of the steering control valve 4 is connected to the rod chamber of the steering actuator. When performing a steering action (such as a left turn), the left position of the lifting control valve 3 and the left position of the steering control valve 4 are energized, and the power unit 2 outputs the hydraulic oil in the oil tank 1 to the P port, and then outputs it to the S1 port through the lifting control valve 3 and the steering control valve 4, and is transported to the rodless chamber of the steering actuator through the S1 port to complete the left steering action. When performing a right turn, the left position of the lifting control valve 3 and the right position of the steering control valve 4 are energized, and the hydraulic oil is transported to the rod chamber of the steering actuator through the S2 port to complete the right steering action. Furthermore, when the lift control valve 3 is in the middle position, the first working oil port of the lift control valve 3 and the return oil port of the lift control valve 3 are connected. That is, assuming that after the left steering action is completed, the lift control valve 3 is first controlled to switch to the middle position. At this time, the S1 port is connected to the oil tank 1, and the hydraulic oil in the rodless chamber of the steering actuator passes through the steering control valve 4 and the lift control valve 3 and flows back to the oil tank 1 through the T port to relieve pressure.

[0033] When the lifting control valve 3 in the hydraulic system of the aerial work platform is in the middle position, the first working oil port of the lifting control valve 3 and the second working oil port of the lifting control valve 3 are both connected to the return oil port of the lifting control valve 3, and the oil inlet of the steering control valve 4 is connected to the first working oil port of the lifting control valve 3, so that the lifting control valve 3 and the steering control valve 4 cooperate to complete the action of the steering actuator and avoid pressure buildup in the steering actuator, and the lifting control valve 3 can independently complete the action of the lifting actuator and avoid pressure buildup, effectively avoiding the problem of misoperation caused by pressure shock and long-term pressure buildup.

[0034] If the lifting actuator needs oil return, an external oil return control valve can be connected to the oil tank 1. If oil return is not required, the lifting action can be completed.

[0035] Optionally, the power device 2 includes a power source 21 and a gear pump 22. The power source 21 can be selected as a motor or an engine. The power source 21 provides mechanical energy to the gear pump 22. The oil inlet of the gear pump 22 is connected to the oil tank 1. The gear pump 22 converts the mechanical energy provided by the power source 21 into hydraulic energy and pumps the hydraulic oil in the oil tank 1 through the oil outlet to the lifting actuator and the steering actuator.

[0036] Optionally, the hydraulic system of the aerial work platform also includes a first relief valve 5, the first oil port of the first relief valve 5 is connected to the first working oil port of the lifting control valve 3 and the oil inlet of the steering control valve 4, the second oil port of the first relief valve 5 is connected to the oil tank 1, the first relief valve 5 can set the pressure, when the steering action is performed, if the pressure of the oil inlet of the steering control valve 4 exceeds the pressure set by the first relief valve 5, the hydraulic oil will flow back to the oil tank 1 through the first relief valve 5, the first relief valve 5 can set the pressure of the S1 port and the S2 port separately, effectively reducing energy loss and improving the endurance of the aerial work platform. The pressure setting of the first relief valve 5 can be set according to the actual use of different models, and it is sufficient to meet the steering action. On the premise of achieving the steering action, the setting of its maximum pressure does not affect other actions such as lifting.

[0037] The hydraulic system of the aerial work platform also includes an outrigger control valve 6, an oil inlet of the outrigger control valve 6 is connected to an oil outlet of a gear pump 22 of a power unit 2, an oil return port of the outrigger control valve 6 is connected to an oil tank 1, a first working oil port of the outrigger control valve 6 is connected to a rod chamber of an outrigger group actuator cylinder, and a second working oil port of the outrigger control valve 6 is connected to a rodless chamber of the outrigger group actuator cylinder. By setting the outrigger control valve 6, it is possible to individually control the outrigger group actuator cylinder.

[0038] Furthermore, the outrigger group actuator oil cylinder includes two outrigger actuator oil cylinders, and the first working oil port of the outrigger control valve 6 is divided into two pipelines and respectively communicated with the rod chambers of the two outrigger actuator oil cylinders to respectively control the actions of the two outrigger actuator oil cylinders and realize the retraction of the two outriggers; the second working oil port of the outrigger control valve 6 is divided into two pipelines and respectively communicated with the rodless chambers of the two outrigger actuator oil cylinders to respectively control the actions of the two outrigger actuator oil cylinders and realize the extension of the two outriggers. This structure can realize the simultaneous action of multiple outriggers. Of course, the outrigger group actuator oil cylinder can also include more than two outrigger actuator oil cylinders.

[0039] Optionally, the hydraulic system of the aerial work platform further includes a shuttle valve 7 and a second relief valve 8, the first working oil port of the leg control valve 6 and the second working oil port of the leg control valve 6 are also connected to the first oil inlet of the shuttle valve 7 and the second oil inlet of the shuttle valve 7 respectively, the oil outlet of the shuttle valve 7 is connected to the first oil port of the second relief valve 8, and the second oil port of the second relief valve 8 is connected to the oil tank 1. For example, when the extension action of the leg execution oil cylinder is controlled, the right position of the leg control valve 6 is energized, the power source 21 drives the gear pump 22 to pump the hydraulic oil in the oil tank 1 to the P port, and then part of the hydraulic oil flows to the second relief valve 8 through the second oil port of the shuttle valve 7 after the leg control valve 6, and the rest of the hydraulic oil flows to the RF port and the RR port to enter the rodless chamber of the leg execution oil cylinder, and the leg execution oil cylinder is extended to complete the extension action of the leg; at this time, the hydraulic oil in the rod chamber of the leg execution oil cylinder passes through the leg control valve 6 through the EF port and the ER port and flows back to the oil tank 1 through the T port. In this structure, a shuttle valve 7 and a second relief valve 8 are provided. When the pressure of the hydraulic oil is lower than the set pressure of the second relief valve 8, the second relief valve 8 is in a closed state. When the pressure of the hydraulic oil is higher than the set pressure of the second relief valve 8, the second relief valve 8 is passively opened, and the hydraulic oil flows back to the oil tank 1, so that the pressure is limited within the set pressure range to ensure the safety of the oil circuit. The second relief valve 8 limits the maximum pressure of the outrigger actuator, that is, the pressure that meets the outrigger movement requirements, and does not cause waste due to excessive pressure, thereby improving the endurance of the entire machine.

[0040] When the outrigger actuator cylinder is controlled to retract, the left position of the outrigger control valve 6 is energized, and the hydraulic oil enters the rod chamber of the outrigger actuator cylinder through the EF port and the ER port. The hydraulic oil in the rodless chamber of the outrigger actuator cylinder flows to the outrigger control valve 6 through the RF port and the RR port and flows back to the oil tank 1 through the T port, completing the outrigger retraction action.

[0041] In order to realize the floating function of the aerial work platform, the hydraulic system of the aerial work platform also includes a floating control valve, the floating control valve includes a first floating control valve 9 and a second floating control valve 10, the floating actuator includes a first floating actuator and a second floating actuator, the oil inlet of the first floating control valve 9 and the oil inlet of the second floating control valve 10 are both connected to the oil outlet of the gear pump 22, the oil return port of the first floating control valve 9 and the oil return port of the second floating control valve 10 are both connected to the oil tank 1, the working oil port of the first floating control valve 9 is connected to the first floating actuator, and the working oil port of the second floating control valve 10 is connected to the second floating actuator. The first floating control valve 9 and the second floating control valve 10 have the same structure. Taking the first floating control valve 9 as an example, the first floating control valve 9 has a first working position and a second working position. When the floating function is not required, the first floating control valve 9 is in the first working position, and the working oil port of the first floating control valve 9 is connected to the return oil port of the first floating control valve 9; when the floating function is required, the first floating control valve 9 is in the second working position, and the oil inlet of the first floating control valve 9 is connected to the working oil port of the first floating control valve 9, so that the gear pump 22 delivers the hydraulic oil in the oil tank 1 to the first floating actuator through the first floating control valve 9. The floating action principle of the second floating actuator is the same as that of the first floating actuator, which will not be repeated here.

[0042] The hydraulic system of the aerial work platform also includes a brake release control valve 20, the oil inlet of the brake release control valve 20 is connected to the oil outlet of the gear pump 22, the oil return port of the brake release control valve 20 is connected to the oil tank 1, and the working oil port of the brake release control valve 20 is connected to the brake release actuator, the accumulator 80 and the pressure sensor respectively, that is, the working oil port of the brake release control valve 20 is connected in parallel to the BR port, the AC port and the PS port, which are respectively used to connect the brake release actuator, the accumulator 80 and the pressure sensor. The brake release control valve 20 has a first working position and a second working position. When the aerial work platform is moving and the pressure sensor detects that the pressure is lower than the lowest value of the set pressure range, the brake release control valve 20 is in the second working position, and the working oil port of the brake release control valve 20 is connected with the oil inlet of the brake release control valve 20, so that the power source 21 drives the gear pump 22 to deliver the hydraulic oil in the oil tank 1 through the brake release control valve 20 to the AC port and enter the accumulator 80 for filling; when the pressure sensor detects that the pressure is higher than the highest value of the set pressure range, the brake release control valve 20 is in the first working position, and the working oil port of the brake release control valve 20 is connected with the return oil port of the brake release control valve 20, the power source 21 stops, and the accumulator 80 is no longer filled with liquid to save energy. When the brake release function needs to be executed, the accumulator 80 provides hydraulic oil for the brake release actuator. The accumulator 80 plays a role of energy storage, which avoids the power source 21 from rotating all the time to provide hydraulic oil during the walking process. The power source 21 does not need to rotate all the time, which effectively improves the endurance. When the vehicle stops traveling, the hydraulic oil in the accumulator 80 flows back to the oil tank 1 through the brake release control valve 20 to prevent misoperation.

[0043] Furthermore, the oil inlet of the floating control valve and the oil inlet of the brake release control valve 20 are both connected to the oil outlet of the gear pump 22 through the main control valve 30, and the oil inlet of the floating control valve and the brake release control valve 20 are both connected to the working oil port of the main control valve 30, and the oil return port of the main control valve 30 is connected to the oil tank 1. The main control valve 30 has a first working position and a second working position. When the floating function and the brake release function are not required to be executed, the main control valve 30 is located in the first working position, and the working oil port of the main control valve 30 is connected to the oil return port of the main control valve 30; when the floating function needs to be executed, the main control valve 30, the first floating control valve 9 and the second floating control valve 10 are all powered and switched to the second working position, the power source 21 drives the gear pump 22 to work, and the gear pump 22 delivers the hydraulic oil in the oil tank 1 to the P port, and outputs to the OL port and the OR port through the main control valve 30, the first floating control valve 9 and the second floating control valve 10 to flow to the first floating actuator and the second floating actuator respectively, completing the floating action.

[0044] Furthermore, a flow valve 40 is provided on the oil circuit after the working oil port of the main control valve 30 and before the oil inlet of the floating control valve and the oil inlet of the brake release control valve 20. When the floating function or the brake release function is executed, the hydraulic oil needs to pass through the flow valve 40 after passing through the main control valve 30 before it can flow to the floating control valve or the brake release control valve 20. By providing the flow valve 40 after the main control valve 30, it is possible to ensure that the flow of hydraulic oil delivered by the gear pump 22 to the floating actuator or the brake release actuator is stable, and is not affected by the load, and can continuously provide stable hydraulic oil for the floating actuator or the brake release actuator. And when executing the floating function, it can ensure that the tires of the aerial work platform are always in contact with the ground during the driving process, thereby improving the safety of the entire machine. In addition, when the aerial work platform does not need to execute the floating function or the brake release function, there will be no additional loss of hydraulic oil, which is more energy-saving.

[0045] Optionally, a pressure reducing valve 70 is provided on the pipeline connecting the oil inlet of the brake release control valve 20 and the working oil port of the main control valve 30. By setting the pressure reducing valve 70, the pressure delivered to the BR port can be set within a certain range. For example: the set pressure of the pressure reducing valve 70 is 3MPa. In the process of hydraulic oil flowing through the pressure reducing valve and being delivered to the BR port, when the pressure of the working oil port of the main control valve 30 is lower than 3MPa, the working pressure of the BR port is the actual pressure of the working oil port of the main control valve 30. When the pressure of the working oil port of the main control valve 30 is higher than 3MPa, the working pressure of the BR port is 3MPa.

[0046] It can be understood that the set pressure of the pressure reducing valve 70 is greater than the highest value of the set pressure range.

[0047] The hydraulic system of the aerial work platform also includes a one-way valve 50, which is arranged at the oil outlet of the gear pump 22 and is located in the oil path before the oil inlet of the lift control valve 3, the oil inlet of the leg control valve 6 and the oil inlet of the main control valve 30. The one-way valve 50 is configured to be unidirectional in the direction from the gear pump 22 to the lift control valve 3, from the gear pump 22 to the leg control valve 6, and from the gear pump 22 to the main control valve 30. By setting the one-way valve 50, the hydraulic oil can be prevented from flowing back to the gear pump 22, thereby preventing the gear pump 22 from reversing and driving the power source 21 to rotate, thereby reducing the probability of failure of the power source 21.

[0048] The hydraulic system of the aerial work platform also includes a main relief valve 60, a first oil port of the main relief valve 60 is connected to the pipeline between the oil outlet of the gear pump 22 and the oil inlet of the lifting control valve 3, the leg control valve 6, and the main control valve 30, and a second oil port of the main relief valve 60 is connected to the oil tank 1. By setting the main relief valve 60, it is possible to release the pressure when the total pressure in the hydraulic system of the aerial work platform exceeds the set pressure of the main relief valve 60, so as to limit the maximum pressure of the entire hydraulic system, avoid damage to components due to excessive pressure, and increase the service life.

[0049] The hydraulic system of the aerial work platform can be applied to different models, such as scissor-type aerial work platforms, off-road aerial work platforms, crawler aerial work platforms, etc., and can complete tasks such as outriggers, lifting, steering, floating, and brake release. It can also be flexibly matched and combined according to needs. For example, if outrigger action is not required, the outrigger control valve 6 can be removed. For another example, if floating action is not required, the floating control valve can be removed. Each action is independent of each other and can be freely combined, with high flexibility. Some functions can also be processed separately as optional modules, which are suitable for different working conditions.

[0050] In this embodiment, the operator can output signals by operating the lower control box or the control handle to complete actions such as outrigger, lifting, steering, floating or brake release.

[0051] In this embodiment, the power source 21 is selected as an electric motor, which can achieve stepless speed regulation. By controlling the speed of the motor, the speed of each action can be controlled separately, reducing additional energy loss; and each action can be started smoothly by controlling the acceleration of the motor, avoiding action shock and improving smoothness; in addition, after each action is completed, the motor can be controlled to stop first, and then the solenoid valves such as the lift control valve 3 and the outrigger control valve 6 can be controlled to delay power off, so as to avoid pressure shock caused by pressure buildup in the pipeline.

[0052] Optionally, the lifting control valve 3, the steering control valve 4 and the outrigger control valve 6 are all three-position four-way valves, and use a valve core of a sliding valve structure, which is highly efficient and low in cost.

[0053] Optionally, the main control valve 30, the floating control valve and the brake release control valve 20 are all two-position three-way valves.

[0054] An embodiment of the present invention further provides an aerial work platform, including the hydraulic system of the aerial work platform described above.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. The hydraulic system of the aerial work platform is characterized by: include: Fuel tank (1); A power device (2), wherein an oil inlet of the power device (2) is connected to the oil tank (1); A lifting control valve (3), wherein the oil inlet of the lifting control valve (3) is connected to the oil outlet of the power device (2), the oil return port of the lifting control valve (3) is connected to the oil tank (1), the second working oil port of the lifting control valve (3) is connected to the lifting actuator, and when the lifting control valve (3) is in the middle position, the first working oil port of the lifting control valve (3) and the second working oil port of the lifting control valve (3) are both connected to the oil return port of the lifting control valve (3); A steering control valve (4), wherein an oil inlet of the steering control valve (4) is communicated with a first working oil port of the lifting control valve (3), an oil return port of the steering control valve (4) is communicated with the oil tank (1), the first working oil port of the steering control valve (4) is communicated with a rodless chamber of a steering actuator, and the second working oil port of the steering control valve (4) is communicated with a rod chamber of the steering actuator; A first overflow valve (5), wherein a first oil port of the first overflow valve (5) is connected to a first working oil port of the lift control valve (3) and an oil inlet of the steering control valve (4), and a second oil port of the first overflow valve (5) is connected to the oil tank (1).

2. The hydraulic system of the aerial work platform according to claim 1, characterized in that: It also includes an outrigger control valve (6), the oil inlet of the outrigger control valve (6) is connected to the oil outlet of the power unit (2), the oil return port of the outrigger control valve (6) is connected to the oil tank (1), the first working oil port of the outrigger control valve (6) is connected to the rod chamber of the outrigger group actuator cylinder, and the second working oil port of the outrigger control valve (6) is connected to the rodless chamber of the outrigger group actuator cylinder.

3. The hydraulic system of the aerial work platform according to claim 2, characterized in that: It also includes a shuttle valve (7) and a second overflow valve (8); the first working oil port of the outrigger control valve (6) and the second working oil port of the outrigger control valve (6) are also respectively connected to the first oil inlet of the shuttle valve (7) and the second oil inlet of the shuttle valve (7); the oil outlet of the shuttle valve (7) is connected to the first oil port of the second overflow valve (8); and the second oil port of the second overflow valve (8) is connected to the oil tank (1).

4. The hydraulic system for an aerial work platform according to claim 1, characterized in that: Also includes: A floating control valve, wherein the oil inlet of the floating control valve is connected to the oil outlet of the power device (2), the oil return port of the floating control valve is connected to the oil tank (1), and the working oil port of the floating control valve is connected to a floating actuator; A brake release control valve (20), wherein the oil inlet of the brake release control valve (20) is connected to the oil outlet of the power device (2), the oil return port of the brake release control valve (20) is connected to the oil tank (1), and the working oil port of the brake release control valve (20) is respectively connected to the brake release actuator, the accumulator (80), and the pressure sensor.

5. The hydraulic system for an aerial work platform according to claim 4, characterized in that: It also includes a main control valve (30), the oil inlet of the main control valve (30) is connected to the oil outlet of the power device (2), the working oil port of the main control valve (30) is connected to the oil inlet of the floating control valve and the oil inlet of the brake release control valve (20), and the oil return port of the main control valve (30) is connected to the oil tank (1).

6. The hydraulic system for an aerial work platform according to claim 1, characterized in that: It also includes a one-way valve (50), which is arranged on a pipeline between the oil outlet of the power device (2) and the oil inlet of the lift control valve (3), and the one-way valve (50) is configured to conduct one-way in the direction from the power device (2) to the lift control valve (3).

7. The hydraulic system for an aerial work platform according to claim 1, characterized in that: It also includes a main overflow valve (60), a first oil port of the main overflow valve (60) being connected to a pipeline between an oil outlet of the power device (2) and an oil inlet of the lift control valve (3), and a second oil port of the main overflow valve (60) being connected to the oil tank (1).

8. The hydraulic system for an aerial work platform according to claim 1, characterized in that: The valve cores of the lifting control valve (3) and the steering control valve (4) are both slide valve structures.

9. Aerial work platform, characterized in that: A hydraulic system for an aerial work platform comprising any one of claims 1 to 8.

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