Outrigger hydraulic control system and method of controlling the same and aerial work platform

Abstract

The application discloses a support leg hydraulic control system, a control method thereof and an aerial work platform. The support leg hydraulic control system comprises a first electromagnetic reversing valve, a first oil port of the first electromagnetic reversing valve being used for being communicated with a hydraulic pump, and a second oil port of the first electromagnetic reversing valve being used for being communicated with an oil tank; a second electromagnetic reversing valve, a first oil port of the second electromagnetic reversing valve being communicated with a third oil port of the first electromagnetic reversing valve; and a cylinder assembly, the cylinder assembly comprising a plurality of cylinder units, each of the cylinder units comprising a cylinder and a third electromagnetic reversing valve, a first oil port of each of the third electromagnetic reversing valves being communicated with a second oil port of the second electromagnetic reversing valve, a rod cavity of each of the cylinders being communicated with a fourth oil port of the first electromagnetic reversing valve, and in each of the cylinder units, a second oil port of the third electromagnetic reversing valve being communicated with a rodless cavity of the cylinder. The support leg hydraulic control system can improve the stability and safety of the support leg cylinder during movement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aerial work, and in particular to a support leg hydraulic control system, a control method thereof, and an aerial work platform. BACKGROUND

[0002] In the technical field of aerial work, in order to expand the use scenarios, a support leg is usually installed on the chassis of an aerial work platform, and the extension and retraction of the support leg cylinder is controlled by a hydraulic control system of the support leg, so as to realize the leveling of the chassis, so that the aerial work platform can safely perform aerial work. In order to prevent the soft leg of the support leg cylinder, that is, to prevent the support leg cylinder from being unable to be locked or the pressure from being unable to be maintained, the conventional support leg hydraulic control system uses a two-position two-way electromagnetic valve and a hydraulic control check valve to realize double locking protection of the cylinder. However, in the initial stage of the retraction of the piston rod of the support leg cylinder, the hydraulic control check valve will appear the phenomenon of repeated and rapid on-off, thereby causing the piston rod of the support leg cylinder to emit a whistling abnormal sound when retracted, and even accompanied by high-frequency vibration. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a support leg hydraulic control system capable of improving the stability of the support leg cylinder during movement.

[0004] The present application also proposes a control method of the support leg hydraulic control system having the above-mentioned support leg hydraulic control system.

[0005] The present application also proposes an aerial work platform having the above-mentioned support leg hydraulic control system.

[0006] The outrigger hydraulic control system according to the first aspect of the present application comprises: a first electromagnetic directional valve, a first oil port of the first electromagnetic directional valve being configured to communicate with a hydraulic pump, a second oil port of the first electromagnetic directional valve being configured to communicate with an oil tank, in a first state of the first electromagnetic directional valve, a third oil port of the first electromagnetic directional valve communicates with the first oil port of the first electromagnetic directional valve, and a fourth oil port of the first electromagnetic directional valve communicates with the second oil port of the first electromagnetic directional valve, in a second state of the first electromagnetic directional valve, the first oil port of the first electromagnetic directional valve communicates with the fourth oil port of the first electromagnetic directional valve, and the third oil port of the first electromagnetic directional valve communicates with the second oil port of the first electromagnetic directional valve; a second electromagnetic directional valve, a first oil port of the second electromagnetic directional valve communicating with the third oil port of the first electromagnetic directional valve; and a plurality of cylinder assemblies, each of the cylinder assemblies comprising a cylinder and a third electromagnetic directional valve, a first oil port of each of the third electromagnetic directional valves communicating with a second oil port of the second electromagnetic directional valve, and a rod cavity of each of the cylinders communicating with the fourth oil port of the first electromagnetic directional valve, and in each of the cylinder assemblies, a second oil port of the third electromagnetic directional valve communicating with a rodless cavity of the cylinder.

[0007] The outrigger hydraulic control system according to the present application has at least the following advantages:

[0008] In the outrigger hydraulic control system, the first oil port of the first electromagnetic directional valve is configured to communicate with the hydraulic pump, the second oil port of the first electromagnetic directional valve is configured to communicate with the oil tank, the third oil port of the first electromagnetic directional valve communicates with the first oil port of the second electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve communicates with the rod cavity of the cylinder of each of the cylinder assemblies, and the second oil port of the second electromagnetic directional valve communicates with the first oil port of the third electromagnetic directional valve of each of the cylinder assemblies, and in each of the cylinder assemblies, the second oil port of the third electromagnetic directional valve communicates with the rodless cavity of the cylinder. Thus, when the aerial work platform needs to be lifted, the piston of the cylinder of each of the cylinder assemblies needs to be extended, i.e., the first electromagnetic directional valve is switched to the first state, and the second electromagnetic directional valve and the third electromagnetic directional valve of each of the cylinder assemblies are switched to the communication state, then the hydraulic oil in the hydraulic pump can enter the rodless cavity of the cylinder of each of the cylinder assemblies through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first oil port of the second electromagnetic directional valve, the second oil port of the second electromagnetic directional valve, the first oil port of the third electromagnetic directional valve of each of the cylinder assemblies, and the second oil port of the third electromagnetic directional valve of each of the cylinder assemblies in sequence, and the hydraulic oil in the rod cavity of each of the cylinder assemblies can enter the oil tank through the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in sequence, so that the piston of the cylinder of each of the cylinder assemblies is extended, and the aerial work platform is lifted.

[0009] When the aerial work platform is lifted to the preset height, the second electromagnetic directional valve, the third electromagnetic directional valve of each oil cylinder unit and the first electromagnetic directional valve are switched to the off state, so that the oil cylinder of each oil cylinder unit is locked.

[0010] When the aerial work platform needs to be lowered, the piston of the oil cylinder of each oil cylinder unit needs to be retracted, that is, the first electromagnetic directional valve is switched to the second state, and the second electromagnetic directional valve and the third electromagnetic directional valve of each oil cylinder unit are switched to the on state, so that the hydraulic oil in the hydraulic pump can enter the rod cavity of each oil cylinder unit through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve in turn, and the hydraulic oil in the rodless cavity of the oil cylinder of each oil cylinder unit can enter the tank through the second oil port of the third electromagnetic directional valve of each oil cylinder unit, the first oil port of the third electromagnetic directional valve of each oil cylinder unit, the second oil port of the second electromagnetic directional valve, the first oil port of the second electromagnetic directional valve, the third oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in turn, so that the piston of the oil cylinder of each oil cylinder unit is retracted, and the aerial work platform is lowered.

[0011] When the aerial work platform is lowered to the preset height, the second electromagnetic directional valve, the third electromagnetic directional valve of each oil cylinder unit and the first electromagnetic directional valve are switched to the off state, so that the oil cylinder of each oil cylinder unit is locked.

[0012] When the aerial work platform starts to descend, that is, the piston of the oil cylinder of each oil cylinder unit starts to retract, the second electromagnetic directional valve, the third electromagnetic directional valve of each oil cylinder unit and the first electromagnetic directional valve will not be quickly switched on and off due to the sudden change of the pressure of the hydraulic oil, so that when the piston of the oil cylinder of each oil cylinder unit starts to retract, the oil cylinder can avoid emitting a whistling abnormal sound, and the oil cylinder can avoid high-frequency vibration, so as to improve the stability of the outrigger oil cylinder during movement.

[0013] According to some embodiments of the present application, the second electromagnetic switching valve is located between the third electromagnetic switching valve and the first electromagnetic switching valve, when the first electromagnetic switching valve is in the first state and the second electromagnetic switching valve and the third electromagnetic switching valve are both powered on, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the oil cylinder in sequence through the first oil port of the first electromagnetic switching valve, the third oil port of the first electromagnetic switching valve, the first oil port of the second electromagnetic switching valve, the second oil port of the second electromagnetic switching valve, the first oil port of the third electromagnetic switching valve and the second oil port of the third electromagnetic switching valve, the hydraulic oil in the rod chamber of the oil cylinder can enter into the oil tank in sequence through the fourth oil port of the first electromagnetic switching valve and the second oil port of the first electromagnetic switching valve, when the first electromagnetic switching valve is in the second state and the second electromagnetic switching valve and the third electromagnetic switching valve are both powered on, the hydraulic oil in the hydraulic pump can enter into the rod chamber of the oil cylinder in sequence through the first oil port of the first electromagnetic switching valve and the fourth oil port of the first electromagnetic switching valve, the hydraulic oil in the rodless chamber of the oil cylinder can enter into the oil tank in sequence through the second oil port of the third electromagnetic switching valve, the first oil port of the third electromagnetic switching valve, the second oil port of the second electromagnetic switching valve, the first oil port of the second electromagnetic switching valve, the third oil port of the first electromagnetic switching valve and the second oil port of the first electromagnetic switching valve.

[0014] According to some embodiments of the present application, the plurality of oil cylinder units comprises a first oil cylinder unit, a second oil cylinder unit, a third oil cylinder unit and a fourth oil cylinder unit, the first oil cylinder unit comprises a first oil cylinder and a third electromagnetic switching valve A, the second oil cylinder unit comprises a second oil cylinder and a third electromagnetic switching valve B, the third oil cylinder unit comprises a third oil cylinder and a third electromagnetic switching valve C, and the fourth oil cylinder unit comprises a fourth oil cylinder and a third electromagnetic switching valve D.

[0015] The rodless chamber of the first oil cylinder is in communication with the second oil port of the third electromagnetic switching valve A, the rodless chamber of the second oil cylinder is in communication with the second oil port of the third electromagnetic switching valve B, the rodless chamber of the third oil cylinder is in communication with the second oil port of the third electromagnetic switching valve C, the rodless chamber of the fourth oil cylinder is in communication with the second oil port of the third electromagnetic switching valve D, and the first oil port of the third electromagnetic switching valve A, the first oil port of the third electromagnetic switching valve B, the first oil port of the third electromagnetic switching valve C and the first oil port of the third electromagnetic switching valve D are all in communication with the second oil port of the second electromagnetic switching valve, and the rod chamber of the first oil cylinder, the rod chamber of the second oil cylinder, the rod chamber of the third oil cylinder and the rod chamber of the fourth oil cylinder are all in communication with the fourth oil port of the first electromagnetic switching valve.

[0016] According to some embodiments of the present application, the outrigger hydraulic control system further comprises a first pipeline and a second pipeline, one end of the first pipeline is in communication with the rodless chamber of the first oil cylinder, the other end of the first pipeline is in communication with the third oil port of the first electromagnetic directional valve, the second electromagnetic directional valve and the third electromagnetic directional valve A are arranged on the first pipeline, one end of the second pipeline is in communication with the rod chamber of the first oil cylinder, the other end of the second pipeline is in communication with the fourth oil port of the first electromagnetic directional valve;

[0017] In the first state of the first electromagnetic directional valve and the second electromagnetic directional valve and the third electromagnetic directional valve A are powered, the hydraulic oil in the hydraulic pump can enter the rodless chamber of the first oil cylinder through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve and the first pipeline in turn, the hydraulic oil in the rod chamber of the first oil cylinder can enter the oil tank through the second pipeline, the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in turn, in the second state of the first electromagnetic directional valve and the second electromagnetic directional valve and the third electromagnetic directional valve A are powered, the hydraulic oil in the hydraulic pump can enter the rod chamber of the first oil cylinder through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve and the second pipeline in turn, the hydraulic oil in the rodless chamber of the first oil cylinder can enter the oil tank through the first pipeline, the third oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in turn.

[0018] According to some embodiments of the present application, the outrigger hydraulic control system further comprises a third pipeline and a fourth pipeline, one end of the third pipeline is in communication with the rodless chamber of the second oil cylinder, the other end of the third pipeline is in communication with the pipeline between the second electromagnetic directional valve and the third electromagnetic directional valve A of the first pipeline, the third electromagnetic directional valve B is arranged on the third pipeline, one end of the fourth pipeline is in communication with the rod chamber of the second oil cylinder, the other end of the fourth pipeline is in communication with the fourth oil port of the first electromagnetic directional valve;

[0019] In the case that the first electromagnetic directional valve is in the first state and the second electromagnetic directional valve and the third electromagnetic directional valve B are both electrified, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the second oil cylinder through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first pipeline and the third pipeline in sequence, and the hydraulic oil in the rod chamber of the second oil cylinder can enter into the oil tank through the fourth pipeline, the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in sequence.

[0020] According to some embodiments of the application, the outrigger hydraulic control system further comprises a fifth pipeline and a sixth pipeline, one end of the fifth pipeline is in communication with the rodless chamber of the third oil cylinder, the other end of the fifth pipeline is in communication with the pipeline between the second electromagnetic directional valve and the third electromagnetic directional valve A of the first pipeline, the third electromagnetic directional valve C is arranged on the fifth pipeline, one end of the sixth pipeline is in communication with the rod chamber of the third oil cylinder, the other end of the sixth pipeline is in communication with the fourth oil port of the first electromagnetic directional valve;

[0021] In the case that the first electromagnetic directional valve is in the first state and the second electromagnetic directional valve and the third electromagnetic directional valve C are both electrified, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the third oil cylinder through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first pipeline and the fifth pipeline in sequence, and the hydraulic oil in the rod chamber of the third oil cylinder can enter into the oil tank through the sixth pipeline, the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in sequence. In the case that the first electromagnetic directional valve is in the second state and the second electromagnetic directional valve and the third electromagnetic directional valve C are both electrified, the hydraulic oil in the hydraulic pump can enter into the rod chamber of the third oil cylinder through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve and the sixth pipeline in sequence, and the hydraulic oil in the rodless chamber of the third oil cylinder can enter into the oil tank through the fifth pipeline, the first pipeline, the third oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in sequence.

[0022] According to some embodiments of the present application, the outrigger hydraulic control system further comprises a seventh pipeline and an eighth pipeline, one end of the seventh pipeline is in communication with the rodless chamber of the fourth oil cylinder, the other end of the seventh pipeline is in communication with the pipeline between the second electromagnetic reversing valve and the third electromagnetic reversing valve A on the first pipeline, the third electromagnetic reversing valve D is arranged on the seventh pipeline, one end of the eighth pipeline is in communication with the rod chamber of the fourth oil cylinder, the other end of the eighth pipeline is in communication with the fourth oil port of the first electromagnetic reversing valve;

[0023] Wherein, when the first electromagnetic reversing valve is in the first state, and the second electromagnetic reversing valve and the third electromagnetic reversing valve D are all powered on, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the fourth oil cylinder in turn through the first oil port of the first electromagnetic reversing valve, the third oil port of the first electromagnetic reversing valve, the first pipeline and the seventh pipeline, the hydraulic oil in the rod chamber of the fourth oil cylinder can enter into the oil tank in turn through the eighth pipeline, the fourth oil port of the first electromagnetic reversing valve and the second oil port of the first electromagnetic reversing valve, when the first electromagnetic reversing valve is in the second state, and the second electromagnetic reversing valve and the third electromagnetic reversing valve D are all powered on, the hydraulic oil in the hydraulic pump can enter into the rod chamber of the fourth oil cylinder in turn through the first oil port of the first electromagnetic reversing valve, the fourth oil port of the first electromagnetic reversing valve and the eighth pipeline, the hydraulic oil in the rodless chamber of the fourth oil cylinder can enter into the oil tank in turn through the seventh pipeline, the first pipeline, the third oil port of the first electromagnetic reversing valve and the second oil port of the first electromagnetic reversing valve.

[0024] The control method of the outrigger hydraulic control system according to the second aspect of the embodiment of the present application comprises: in the first case: controlling the driving source to be powered on, so that the driving source drives the hydraulic pump to output hydraulic oil; controlling the first electromagnetic directional valve to be powered on, so that the first electromagnetic directional valve is switched to the first state; controlling the second electromagnetic directional valve to be powered on, so that the first oil port of the second electromagnetic directional valve is in communication with the second oil port of the second electromagnetic directional valve; controlling the third electromagnetic directional valve of each oil cylinder unit to be powered on, so that the first oil port of the third electromagnetic directional valve is in communication with the second oil port of the third electromagnetic directional valve, so that the hydraulic oil in the hydraulic pump sequentially passes through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first oil port of the second electromagnetic directional valve, the second oil port of the second electromagnetic directional valve, the first oil port of the third electromagnetic directional valve of each oil cylinder unit, and the second oil port of the third electromagnetic directional valve of each oil cylinder unit into the rodless cavity of the oil cylinder of each oil cylinder unit, and the hydraulic oil in the rod cavity of the oil cylinder of each oil cylinder unit sequentially passes through the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve into the oil tank; controlling the driving source and the third electromagnetic directional valve of each oil cylinder unit to be powered off, so that the oil cylinder of each oil cylinder unit is locked; within a preset time when the driving source and the third electromagnetic directional valve of each oil cylinder unit are powered off, controlling the second electromagnetic directional valve and the first electromagnetic directional valve to be powered off.

[0025] The control method of the outrigger hydraulic control system according to the embodiment of the present application has at least the following beneficial effects:

[0026] In the control method of the above-mentioned outrigger hydraulic control system, the driving source is controlled to be powered on, so that the driving source drives the hydraulic pump to output hydraulic oil; the first electromagnetic directional valve is controlled to be powered on, so that the first electromagnetic directional valve is switched to the first state; and the second electromagnetic directional valve and the third electromagnetic directional valve of each oil cylinder unit are controlled to be powered on, so that the hydraulic oil in the hydraulic pump sequentially passes through the first electromagnetic directional valve, the second electromagnetic directional valve, and the third electromagnetic directional valve of each oil cylinder unit, and then enters the rodless chamber of the oil cylinder of each oil cylinder unit, and the hydraulic oil in the rod chamber of the oil cylinder of each oil cylinder unit passes through the first electromagnetic directional valve and then enters the oil tank. Thus, in the case that the first electromagnetic directional valve is in the first state and the second electromagnetic directional valve and the third electromagnetic directional valve of each oil cylinder unit are powered on, the oil cylinder of each oil cylinder unit can be extended, so as to realize the lifting of the aerial work platform. In this process, the hydraulic oil in the hydraulic pump sequentially passes through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first oil port of the second electromagnetic directional valve, the second oil port of the second electromagnetic directional valve, the first oil port of the third electromagnetic directional valve of each oil cylinder unit, and the second oil port of the third electromagnetic directional valve of each oil cylinder unit, and then enters the rodless chamber of the oil cylinder of each oil cylinder unit; and the hydraulic oil in the rod chamber of the oil cylinder of each oil cylinder unit can sequentially pass through the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve, and then enter the oil tank.

[0027] When the above-mentioned aerial work platform is lifted to a preset height, the driving source and the third electromagnetic directional valve of each oil cylinder unit are controlled to be powered off, so that the driving source and the third electromagnetic directional valve of each oil cylinder unit are switched to the off state, and the oil cylinder of each oil cylinder unit is locked.

[0028] Within a preset time after the driving source and the third electromagnetic directional valve of each oil cylinder unit are powered off, the second electromagnetic directional valve and the first electromagnetic directional valve are controlled to be powered off, that is, the second electromagnetic directional valve and the first electromagnetic directional valve are powered off in a delayed manner after the driving source and the third electromagnetic directional valve of each oil cylinder unit are powered off. In this way, in the case that the driving source and the third electromagnetic directional valve of each oil cylinder unit are powered off, the pressure of the hydraulic oil in the pipeline connecting the second electromagnetic directional valve and the third electromagnetic directional valve of each oil cylinder unit can be reduced, so that the hydraulic oil in the pipeline can be prevented from being sprayed to the outside from the pipeline when the pipeline is maintained, thereby improving the safety during the maintenance of the pipeline.

[0029] The control method of the outrigger hydraulic control system according to the third aspect of the embodiment of the present application comprises: in the second case: controlling the driving source to be powered on, so that the driving source drives the hydraulic pump to output hydraulic oil; controlling the first electromagnetic directional valve to be powered on, so that the first electromagnetic directional valve is switched to the second state; controlling the second electromagnetic directional valve to be powered on, so that the first oil port of the second electromagnetic directional valve communicates with the second oil port of the second electromagnetic directional valve; controlling the third electromagnetic directional valve of each oil cylinder unit to be powered on, so that the first oil port of the third electromagnetic directional valve communicates with the second oil port of the third electromagnetic directional valve, so that the hydraulic oil in the hydraulic pump enters the rod cavity of each oil cylinder of each oil cylinder unit through the first oil port of the first electromagnetic directional valve and the fourth oil port of the first electromagnetic directional valve in turn, and the hydraulic oil in the rodless cavity of each oil cylinder of each oil cylinder unit enters the oil tank through the second oil port of the third electromagnetic directional valve of each oil cylinder unit, the first oil port of the third electromagnetic directional valve of each oil cylinder unit, the second oil port of the second electromagnetic directional valve, the first oil port of the second electromagnetic directional valve, the third oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in turn; controlling the driving source and the third electromagnetic directional valve of each oil cylinder unit to be powered off, so that the oil cylinder of each oil cylinder unit is locked; controlling the second electromagnetic directional valve and the first electromagnetic directional valve to be powered off within a preset time when the driving source and the third electromagnetic directional valve of each oil cylinder unit are powered off.

[0030] The control method of the outrigger hydraulic control system according to the embodiment of the present application has at least the following beneficial effects:

[0031] In the control method of the outrigger hydraulic control system, the driving source is controlled to be powered on, so that the driving source drives the hydraulic pump to output hydraulic oil; the first electromagnetic directional valve is controlled to be powered on, so that the first electromagnetic directional valve is switched to the second state; and the second electromagnetic directional valve and the third electromagnetic directional valve of each cylinder unit are controlled to be powered on, so that the hydraulic oil in the hydraulic pump enters the rod cavity of the cylinder of each cylinder unit through the first electromagnetic directional valve, and the hydraulic oil in the rodless cavity of the cylinder of each cylinder unit enters the oil tank through the third electromagnetic directional valve of each cylinder unit, the second electromagnetic directional valve, and the first electromagnetic directional valve in turn. Thus, in the case that the first electromagnetic directional valve is in the second state and the second electromagnetic directional valve and the third electromagnetic directional valve of each cylinder unit are powered on, the cylinder of each cylinder unit can be retracted to realize the lowering of the aerial work platform. In this process, the hydraulic oil in the hydraulic pump can enter the rod cavity of the cylinder of each cylinder unit through the first oil port of the first electromagnetic directional valve and the fourth oil port of the first electromagnetic directional valve in turn; and the hydraulic oil in the rodless cavity of the cylinder of each cylinder unit can enter the oil tank through the second oil port of the third electromagnetic directional valve of each cylinder unit, the first oil port of the third electromagnetic directional valve of each cylinder unit, the second oil port of the second electromagnetic directional valve, the first oil port of the second electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, and the second oil port of the first electromagnetic directional valve in turn.

[0032] When the aerial work platform is lowered to the preset height, the driving source and the third electromagnetic directional valve of each cylinder unit are controlled to be powered off, so that the driving source and the third electromagnetic directional valve of each cylinder unit are switched to the open state, and the cylinder of each cylinder unit is locked.

[0033] Within the preset time when the driving source and the third electromagnetic directional valve of each cylinder unit are powered off, the second electromagnetic directional valve and the first electromagnetic directional valve are controlled to be powered off, that is, the second electromagnetic directional valve and the first electromagnetic directional valve are powered off in a delayed manner when the driving source and the third electromagnetic directional valve of each cylinder unit are powered off. In this way, when the driving source and the third electromagnetic directional valve of each cylinder unit are powered off, the pressure of the hydraulic oil in the pipeline connected between the first electromagnetic directional valve and the rod cavity of each cylinder unit can be reduced, so that the hydraulic oil in the pipeline can be prevented from being sprayed to the outside from the pipeline when the pipeline is maintained, thereby improving the safety when the pipeline is maintained.

[0034] In addition, when the aerial work platform starts to descend, i.e. the piston of the oil cylinder of each oil cylinder unit starts to contract, the second electromagnetic reversing valve, the third electromagnetic reversing valve of each oil cylinder unit and the first electromagnetic reversing valve are not switched on and off rapidly due to the sudden change of the pressure of the hydraulic oil after being powered, so that when the piston of the oil cylinder of each oil cylinder unit starts to contract, the oil cylinder can avoid emitting a howling abnormal sound and high-frequency vibration, thereby improving the stability of the outrigger oil cylinder during movement.

[0035] The aerial work platform according to the fourth aspect of the present application comprises the outrigger hydraulic control system as described above or the control method of the outrigger hydraulic control system as described above.

[0036] The aerial work platform according to the embodiments of the present application has at least the following beneficial effects:

[0037] In the aerial work platform as described above, since the outrigger hydraulic control system as described above can improve the stability of the outrigger oil cylinder during movement, the aerial work platform as described above has good stability during lifting and descending. In addition, since the outrigger hydraulic control system as described above can lock the oil cylinder of each oil cylinder unit, the aerial work platform as described above has good safety when working at a preset height. BRIEF DESCRIPTION OF DRAWINGS

[0038] The present application will be further described below in conjunction with the drawings and embodiments, in which:

[0039] Figure 1 FIG. 1 is a structural schematic diagram of the outrigger hydraulic control system according to an embodiment of the present application;

[0040] Figure 2 FIG. 2 is a structural schematic diagram of the outrigger hydraulic control system when the first electromagnetic reversing valve is in the first state according to an embodiment of the present application;

[0041] Figure 3 FIG. 3 is a structural schematic diagram of the outrigger hydraulic control system when the first electromagnetic reversing valve is in the second state according to an embodiment of the present application.

[0042] REFERENCE NUMERALS:

[0043] 100, first electromagnetic reversing valve;

[0044] 200, hydraulic pump; 210, oil tank; 220, driving source; 230, controller; 240, operation key;

[0045] 300, second electromagnetic reversing valve;

[0046] 400, first oil cylinder unit; 410, first oil cylinder; 420, third electromagnetic reversing valve A;

[0047] 500, second oil cylinder unit; 510, second oil cylinder; 520, third electromagnetic switching valve B;

[0048] 600, third oil cylinder unit; 610, third oil cylinder; 620, third electromagnetic switching valve C;

[0049] 700, fourth oil cylinder unit; 710, fourth oil cylinder; 720, third electromagnetic switching valve D;

[0050] 810, first pipeline; 820, second pipeline; 830, third pipeline; 840, fourth pipeline; 850, fifth pipeline; 860, sixth pipeline; 870, seventh pipeline; 880, eighth pipeline. DETAILED DESCRIPTION

[0051] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended only for the purpose of explaining the present application, and should not be construed as limiting the present application.

[0052] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, etc. is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or component referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application.

[0053] In the description of the present application, the plural refers to two or more. If there is a description of first, second, it is only for the purpose of distinguishing technical features, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0054] In the description of the present application, unless otherwise explicitly limited, the words such as arrangement, installation, connection, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0055] Referring to Figures 1 to 3 As shown in the drawings, an embodiment of the present application is a leg hydraulic control system, which comprises a first electromagnetic switching valve 100, a second electromagnetic switching valve 300, and an oil cylinder assembly.

[0056] Specifically, the first oil port a of the first electromagnetic directional valve 100 is configured to communicate with the hydraulic pump 200, the second oil port b of the first electromagnetic directional valve 100 is configured to communicate with the oil tank 210, in the case that the first electromagnetic directional valve 100 is in the first state, the first oil port a of the first electromagnetic directional valve 100 communicates with the third oil port c of the first electromagnetic directional valve 100, and the fourth oil port d of the first electromagnetic directional valve 100 communicates with the second oil port b of the first electromagnetic directional valve 100, in the case that the first electromagnetic directional valve 100 is in the second state, the first oil port a of the first electromagnetic directional valve 100 communicates with the fourth oil port d of the first electromagnetic directional valve 100, and the third oil port c of the first electromagnetic directional valve 100 communicates with the second oil port b of the first electromagnetic directional valve 100; the first oil port e of the second electromagnetic directional valve 300 communicates with the third oil port c of the first electromagnetic directional valve 100; the oil cylinder assembly comprises a plurality of oil cylinder units, each of which comprises an oil cylinder and a third electromagnetic directional valve, the first oil port of each third electromagnetic directional valve communicates with the second oil port f of the second electromagnetic directional valve 300, the rodless cavity of each oil cylinder communicates with the fourth oil port d of the first electromagnetic directional valve 100, and in each oil cylinder unit, the second oil port of the third electromagnetic directional valve communicates with the rodless cavity of the oil cylinder; wherein the second electromagnetic directional valve 300 and the third electromagnetic directional valve of each oil cylinder unit are configured to lock the oil cylinder of each oil cylinder unit.

[0057] Specifically, in one of the embodiments, the first electromagnetic directional valve 100 can be a three-position four-way electromagnetic directional valve, in addition, in other embodiments, the first electromagnetic directional valve 100 can also be other types of electromagnetic directional valves, such as a three-position five-way electromagnetic directional valve, or an electromagnetic directional valve with a manual control function, etc.

[0058] Further, in one of the embodiments, the second electromagnetic directional valve 300 and the third electromagnetic directional valve can be two-position two-way electromagnetic directional valves, in addition, in other embodiments, the second electromagnetic directional valve 300 and the third electromagnetic directional valve can also be other types of electromagnetic directional valves, such as two-position three-way electromagnetic directional valves, or electromagnetic directional valves with a manual control function, etc.

[0059] In the above-mentioned outrigger hydraulic control system, the first oil port a of the first electromagnetic directional valve 100 is used for communication with the hydraulic pump 200, the second oil port b of the first electromagnetic directional valve 100 is used for communication with the oil tank 210, the third oil port c of the first electromagnetic directional valve 100 is communicated with the first oil port e of the second electromagnetic directional valve 300, the fourth oil port d of the first electromagnetic directional valve 100 is communicated with the rod cavity of the oil cylinder of each oil cylinder unit, and the second oil port f of the second electromagnetic directional valve 300 is communicated with the first oil port of the third electromagnetic directional valve of each oil cylinder unit, and in each oil cylinder unit, the second oil port of the third electromagnetic directional valve is communicated with the rodless cavity of the oil cylinder. In this way, when it is needed to lift the aerial work platform, the piston of the oil cylinder of each oil cylinder unit needs to be extended, that is, the first electromagnetic directional valve 100 is switched to the first state, and the second electromagnetic directional valve 300 and the third electromagnetic directional valve of each oil cylinder unit are switched to the communication state, then the hydraulic oil in the hydraulic pump 200 can enter the rodless cavity of the oil cylinder of each oil cylinder unit in turn through the first oil port a of the first electromagnetic directional valve 100, the third oil port c of the first electromagnetic directional valve 100, the first oil port e of the second electromagnetic directional valve 300, the second oil port f of the second electromagnetic directional valve 300, the first oil port of the third electromagnetic directional valve of each oil cylinder unit, and the second oil port of the third electromagnetic directional valve of each oil cylinder unit, and the hydraulic oil in the rod cavity of each oil cylinder unit can enter the oil tank 210 in turn through the fourth oil port d of the first electromagnetic directional valve 100 and the second oil port b of the first electromagnetic directional valve 100, so that the piston of the oil cylinder of each oil cylinder unit is extended, so that the aerial work platform is lifted.

[0060] When the above-mentioned aerial work platform is lifted to a preset height, the second electromagnetic directional valve 300, the third electromagnetic directional valve of each oil cylinder unit, and the first electromagnetic directional valve 100 are switched to the off state, so that the oil cylinder of each oil cylinder unit is locked.

[0061] When the aerial work platform needs to be lowered, the piston of the oil cylinder of each oil cylinder unit needs to be retracted, that is, the first electromagnetic reversing valve 100 is switched to the second state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve of each oil cylinder unit are switched to the communication state, then the hydraulic oil in the hydraulic pump 200 can enter the rod cavity of each oil cylinder unit through the first oil port a of the first electromagnetic reversing valve 100, the fourth oil port d of the first electromagnetic reversing valve 100 in turn, the hydraulic oil in the rodless cavity of the oil cylinder of each oil cylinder unit can enter the tank 210 through the second oil port of the third electromagnetic reversing valve of each oil cylinder unit, the first oil port of the third electromagnetic reversing valve of each oil cylinder unit, the second oil port f of the second electromagnetic reversing valve 300, the first oil port e of the second electromagnetic reversing valve 300, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100 in turn, so that the piston of the oil cylinder of each oil cylinder unit can be retracted to lower the aerial work platform.

[0062] When the above-mentioned aerial work platform is lowered to the preset height, the second electromagnetic reversing valve 300, the third electromagnetic reversing valve of each oil cylinder unit and the first electromagnetic reversing valve 100 are switched to the off state, that is, the oil cylinder of each oil cylinder unit is locked.

[0063] When the aerial work platform starts to lower, that is, the piston of the oil cylinder of each oil cylinder unit starts to retract, the second electromagnetic reversing valve 300, the third electromagnetic reversing valve of each oil cylinder unit and the first electromagnetic reversing valve 100 will not be quickly switched on and off due to the sudden change of the pressure of the hydraulic oil, so that when the piston of the oil cylinder of each oil cylinder unit starts to retract, the oil cylinder can avoid emitting a whistling abnormal sound, and the oil cylinder can avoid high-frequency vibration, so as to improve the stability of the outrigger oil cylinder during movement.

[0064] Reference Figures 1 to 3As shown, it can be understood that the second electromagnetic reversing valve 300 is located between the third electromagnetic reversing valve and the first electromagnetic reversing valve 100, in the case that the first electromagnetic reversing valve 100 is in the first state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve are both powered, the hydraulic oil in the hydraulic pump 200 can pass through the first oil port a of the first electromagnetic reversing valve 100, the third oil port c of the first electromagnetic reversing valve 100, the first oil port e of the second electromagnetic reversing valve 300, the second oil port f of the second electromagnetic reversing valve 300, the first oil port of the third electromagnetic reversing valve, and the second oil port of the third electromagnetic reversing valve in sequence to enter the rodless chamber of the oil cylinder, and the hydraulic oil in the rod chamber of the oil cylinder can pass through the fourth oil port d of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100 in sequence to enter the oil tank 210, in the case that the first electromagnetic reversing valve 100 is in the second state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve are both powered, the hydraulic oil in the hydraulic pump 200 can pass through the first oil port a of the first electromagnetic reversing valve 100 and the fourth oil port d of the first electromagnetic reversing valve 100 to enter the rod chamber of the oil cylinder, and the hydraulic oil in the rodless chamber of the oil cylinder can pass through the second oil port of the third electromagnetic reversing valve, the first oil port of the third electromagnetic reversing valve, the second oil port f of the second electromagnetic reversing valve 300, the first oil port e of the second electromagnetic reversing valve 300, the third oil port c of the first electromagnetic reversing valve 100, and the second oil port b of the first electromagnetic reversing valve 100 to enter the oil tank 210.

[0065] Thus, when it is needed to lift the aerial work platform, the piston of the oil cylinder of each oil cylinder unit needs to be extended, that is, the first electromagnetic reversing valve 100 is switched to the first state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve of each oil cylinder unit are powered, then the hydraulic oil in the hydraulic pump 200 can pass through the first oil port a of the first electromagnetic reversing valve 100, the third oil port c of the first electromagnetic reversing valve 100, the first oil port e of the second electromagnetic reversing valve 300, the second oil port f of the second electromagnetic reversing valve 300, the first oil port of the third electromagnetic reversing valve of each oil cylinder unit, and the second oil port of the third electromagnetic reversing valve of each oil cylinder unit in sequence to enter the rodless chamber of the oil cylinder of each oil cylinder unit, and the hydraulic oil in the rod chamber of each oil cylinder unit can pass through the fourth oil port d of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100 in sequence to enter the oil tank 210, so that the piston of the oil cylinder of each oil cylinder unit can be extended to lift the aerial work platform.

[0066] When it is needed to lower the aerial work platform, the pistons of the oil cylinders of each oil cylinder unit need to be retracted, that is, the first electromagnetic reversing valve 100 is switched to the second state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve of each oil cylinder unit are electrified, so that the hydraulic oil in the hydraulic pump 200 can enter the rod cavity of each oil cylinder unit in turn through the first oil port a of the first electromagnetic reversing valve 100 and the fourth oil port d of the first electromagnetic reversing valve 100, and the hydraulic oil in the rodless cavity of the oil cylinder of each oil cylinder unit can enter the oil tank 210 in turn through the second oil port of the third electromagnetic reversing valve of each oil cylinder unit, the first oil port of the third electromagnetic reversing valve of each oil cylinder unit, the second oil port f of the second electromagnetic reversing valve 300, the first oil port e of the second electromagnetic reversing valve 300, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100, so that the pistons of the oil cylinders of each oil cylinder unit can be retracted to lower the aerial work platform.

[0067] Referring to Figure 1 As shown in the figure, it can be understood that the plurality of oil cylinder units include a first oil cylinder unit 400, a second oil cylinder unit 500, a third oil cylinder unit 600 and a fourth oil cylinder unit 700, the first oil cylinder unit 400 includes a first oil cylinder 410 and a third electromagnetic reversing valve A 420, the second oil cylinder unit 500 includes a second oil cylinder 510 and a third electromagnetic reversing valve B 520, the third oil cylinder unit 600 includes a third oil cylinder 610 and a third electromagnetic reversing valve C 620, and the fourth oil cylinder unit 700 includes a fourth oil cylinder 710 and a third electromagnetic reversing valve D 720; wherein the rodless cavity of the first oil cylinder 410 communicates with the second oil port h of the third electromagnetic reversing valve A 420, the rodless cavity of the second oil cylinder 510 communicates with the second oil port j of the third electromagnetic reversing valve B 520, the rodless cavity of the third oil cylinder 610 communicates with the second oil port m of the third electromagnetic reversing valve C 620, the rodless cavity of the fourth oil cylinder 710 communicates with the second oil port p of the third electromagnetic reversing valve D 720, and the first oil port g of the third electromagnetic reversing valve A 420, the first oil port i of the third electromagnetic reversing valve B 520, the first oil port k of the third electromagnetic reversing valve C 620 and the first oil port n of the third electromagnetic reversing valve D 720 all communicate with the second oil port f of the second electromagnetic reversing valve 300, and the rod cavity of the first oil cylinder 410, the rod cavity of the second oil cylinder 510, the rod cavity of the third oil cylinder 610 and the rod cavity of the fourth oil cylinder 710 all communicate with the fourth oil port d of the first electromagnetic reversing valve 100.

[0068] When the aerial work platform needs to be lifted, the first oil cylinder 410 of the first oil cylinder unit 400, the second oil cylinder 510 of the second oil cylinder unit 500, the third oil cylinder 610 of the third oil cylinder unit 600 and the fourth oil cylinder 710 of the fourth oil cylinder unit 700 are simultaneously extended. That is, the first electromagnetic reversing valve 100 is switched to the first state, and the second electromagnetic reversing valve 300, the third electromagnetic reversing valve A420 of the first oil cylinder unit 400, the third electromagnetic reversing valve B520 of the second oil cylinder unit 500, the third electromagnetic reversing valve C620 of the third oil cylinder unit 600 and the third electromagnetic reversing valve D720 of the fourth oil cylinder unit 700 are all powered on. The hydraulic oil in the hydraulic pump 200 can first pass through the first electromagnetic reversing valve 100 into the second electromagnetic reversing valve 300, and then pass through the third electromagnetic reversing valve A420, the third electromagnetic reversing valve B520, the third electromagnetic reversing valve C620 and the third electromagnetic reversing valve D720 from the second electromagnetic reversing valve 300 into the rodless cavity of the first oil cylinder 410, the rodless cavity of the second oil cylinder 510, the rodless cavity of the third oil cylinder 610 and the rodless cavity of the fourth oil cylinder 710, respectively. The hydraulic oil in the rod cavity of the first oil cylinder 410, the hydraulic oil in the rod cavity of the second oil cylinder 510, the hydraulic oil in the rod cavity of the third oil cylinder 610 and the hydraulic oil in the rod cavity of the fourth oil cylinder 710 can all pass through the first electromagnetic reversing valve 100 into the oil tank 210, so that the pistons of the first oil cylinder 410, the second oil cylinder 510, the third oil cylinder 610 and the fourth oil cylinder 710 can be simultaneously extended, so that the aerial work platform can be lifted.In this process, the hydraulic oil in the hydraulic pump 200 can enter into the rodless chamber of the first oil cylinder 410 in sequence through the first oil port a of the first electromagnetic directional valve 100, the third oil port c of the first electromagnetic directional valve 100, the first oil port e of the second electromagnetic directional valve 300, the second oil port f of the second electromagnetic directional valve 300, the first oil port g of the third electromagnetic directional valve A 420, and the second oil port h of the third electromagnetic directional valve A 420; enter into the rodless chamber of the second oil cylinder 510 in sequence through the first oil port a of the first electromagnetic directional valve 100, the third oil port c of the first electromagnetic directional valve 100, the first oil port e of the second electromagnetic directional valve 300, the second oil port f of the second electromagnetic directional valve 300, the first oil port i of the third electromagnetic directional valve B 520, and the second oil port j of the third electromagnetic directional valve B 520; enter into the rodless chamber of the third oil cylinder 610 in sequence through the first oil port a of the first electromagnetic directional valve 100, the third oil port c of the first electromagnetic directional valve 100, the first oil port e of the second electromagnetic directional valve 300, the second oil port f of the second electromagnetic directional valve 300, the first oil port k of the third electromagnetic directional valve C 620, and the second oil port m of the third electromagnetic directional valve C 620; and enter into the rodless chamber of the fourth oil cylinder 710 in sequence through the first oil port a of the first electromagnetic directional valve 100, the third oil port c of the first electromagnetic directional valve 100, the first oil port e of the second electromagnetic directional valve 300, the second oil port f of the second electromagnetic directional valve 300, the first oil port n of the third electromagnetic directional valve D 720, and the second oil port p of the third electromagnetic directional valve D 720; the hydraulic oil in the rod chamber of the first oil cylinder 410, the hydraulic oil in the rod chamber of the second oil cylinder 510, the hydraulic oil in the rod chamber of the third oil cylinder 610, and the hydraulic oil in the rod chamber of the fourth oil cylinder 710 can enter into the oil tank 210 in sequence through the fourth oil port d of the first electromagnetic directional valve 100 and the second oil port b of the first electromagnetic directional valve 100.

[0069] When the aerial work platform needs to be lowered, the first oil cylinder 410 of the first oil cylinder unit 400, the second oil cylinder 510 of the second oil cylinder unit 500, the third oil cylinder 610 of the third oil cylinder unit 600 and the fourth oil cylinder 710 of the fourth oil cylinder unit 700 need to be retracted at the same time. That is, the first electromagnetic reversing valve 100 can be switched to the second state, and the second electromagnetic reversing valve 300, the third electromagnetic reversing valve A420 of the first oil cylinder unit 400, the third electromagnetic reversing valve B520 of the second oil cylinder unit 500, the third electromagnetic reversing valve C620 of the third oil cylinder unit 600 and the third electromagnetic reversing valve D720 of the fourth oil cylinder unit 700 are all powered on, then the hydraulic oil in the hydraulic pump 200 can enter the rod cavity of the first oil cylinder 410, the rod cavity of the second oil cylinder 510, the rod cavity of the third oil cylinder 610 and the rod cavity of the fourth oil cylinder 710 respectively through the first electromagnetic reversing valve 100; the hydraulic oil in the rodless cavity of the first oil cylinder 410, the hydraulic oil in the rodless cavity of the second oil cylinder 510, the hydraulic oil in the rodless cavity of the third oil cylinder 610 and the hydraulic oil in the rodless cavity of the fourth oil cylinder 710 can enter the third electromagnetic reversing valve A420, the third electromagnetic reversing valve B520, the third electromagnetic reversing valve C620 and the third electromagnetic reversing valve D720 respectively, then enter the second electromagnetic reversing valve 300 and the first electromagnetic reversing valve 100 in turn through the third electromagnetic reversing valve A420, the third electromagnetic reversing valve B520, the third electromagnetic reversing valve C620 and the third electromagnetic reversing valve D720, and finally enter the oil tank 210 through the first electromagnetic reversing valve 100, so that the pistons of the first oil cylinder 410, the second oil cylinder 510, the third oil cylinder 610 and the fourth oil cylinder 710 can be retracted at the same time, so that the aerial work platform can be lowered.In this process, the hydraulic oil in the hydraulic pump 200 can enter into the rod cavity of the first oil cylinder 410, the rod cavity of the second oil cylinder 510, the rod cavity of the third oil cylinder 610 and the rod cavity of the fourth oil cylinder 710 in sequence through the first oil port a of the first electromagnetic reversing valve 100 and the fourth oil port d of the first electromagnetic reversing valve 100 respectively; the hydraulic oil in the rodless cavity of the first oil cylinder 410 can enter into the oil tank 210 in sequence through the second oil port h of the third electromagnetic reversing valve A 420, the first oil port g of the third electromagnetic reversing valve A 420, the second oil port f of the second electromagnetic reversing valve 300, the first oil port e of the second electromagnetic reversing valve 300, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100; the hydraulic oil in the rodless cavity of the second oil cylinder 510 can enter into the oil tank 210 in sequence through the second oil port j of the third electromagnetic reversing valve B 520, the first oil port i of the third electromagnetic reversing valve B 520, the second oil port f of the second electromagnetic reversing valve 300, the first oil port e of the second electromagnetic reversing valve 300, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100; the hydraulic oil in the rodless cavity of the third oil cylinder 610 can enter into the oil tank 210 in sequence through the second oil port m of the third electromagnetic reversing valve C 620, the first oil port k of the third electromagnetic reversing valve C 620, the second oil port f of the second electromagnetic reversing valve 300, the first oil port e of the second electromagnetic reversing valve 300, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100; the hydraulic oil in the rodless cavity of the fourth oil cylinder 710 can enter into the oil tank 210 in sequence through the second oil port p of the third electromagnetic reversing valve D 720, the first oil port n of the third electromagnetic reversing valve D 720, the second oil port f of the second electromagnetic reversing valve 300, the first oil port e of the second electromagnetic reversing valve 300, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100.

[0070] Referring to Figures 1 to 3As shown, it can be understood that the outrigger hydraulic control system further comprises a first pipeline 810 and a second pipeline 820, one end of the first pipeline 810 is in communication with the rodless chamber of the first oil cylinder 410, the other end of the first pipeline 810 is in communication with the third oil port c of the first electromagnetic directional valve 100, the second electromagnetic directional valve 300 and the third electromagnetic directional valve A 420 are arranged on the first pipeline 810, one end of the second pipeline 820 is in communication with the rod chamber of the first oil cylinder 410, the other end of the second pipeline 820 is in communication with the fourth oil port d of the first electromagnetic directional valve 100; wherein, in the case that the first electromagnetic directional valve 100 is in the first state, and the second electromagnetic directional valve 300 and the third electromagnetic directional valve A 420 are all powered, the hydraulic oil in the hydraulic pump 200 can enter into the rodless chamber of the first oil cylinder 410 in turn through the first oil port a of the first electromagnetic directional valve 100, the third oil port c of the first electromagnetic directional valve 100 and the first pipeline 810, the hydraulic oil in the rod chamber of the first oil cylinder 410 can enter into the oil tank 210 in turn through the second pipeline 820, the fourth oil port d of the first electromagnetic directional valve 100 and the second oil port b of the first electromagnetic directional valve 100, in the case that the first electromagnetic directional valve 100 is in the second state, and the second electromagnetic directional valve 300 and the third electromagnetic directional valve A 420 are all powered, the hydraulic oil in the hydraulic pump 200 can enter into the rod chamber of the first oil cylinder 410 in turn through the first oil port a of the first electromagnetic directional valve 100, the fourth oil port d of the first electromagnetic directional valve 100 and the second pipeline 820, the hydraulic oil in the rodless chamber of the first oil cylinder 410 can enter into the oil tank 210 in turn through the first pipeline 810, the third oil port c of the first electromagnetic directional valve 100 and the second oil port b of the first electromagnetic directional valve 100.

[0071] When the aerial work platform needs to be lifted, the first oil cylinder 410 needs to be extended. That is, the first electromagnetic directional valve 100 is switched to the first state, and the second electromagnetic directional valve 300 and the third electromagnetic directional valve A 420 are powered, so that the hydraulic oil in the hydraulic pump 200 can first enter the third oil port c of the first electromagnetic directional valve 100 through the first oil port a of the first electromagnetic directional valve 100, then enter the rodless cavity of the first oil cylinder 410 through the first pipeline 810 communicated with the third oil port c of the first electromagnetic directional valve 100, and the hydraulic oil in the rod cavity of the first oil cylinder 410 can first enter the second pipeline 820, then enter the first electromagnetic directional valve 100 through the fourth oil port d of the first electromagnetic directional valve 100 communicated with the second pipeline 820, and finally enter the tank 210 through the second oil port b of the first electromagnetic directional valve 100 communicated with the fourth oil port d of the first electromagnetic directional valve 100, so that the piston of the first oil cylinder 410 can be extended. In this process, the hydraulic oil in the hydraulic pump 200 can enter the rodless cavity of the first oil cylinder 410 in turn through the first oil port e of the second electromagnetic directional valve 300, the second oil port f of the second electromagnetic directional valve 300, the first oil port g of the third electromagnetic directional valve A 420 and the second oil port h of the third electromagnetic directional valve A 420 when flowing through the first pipeline 810.

[0072] When the aerial work platform needs to be lowered, the first oil cylinder 410 needs to be retracted. That is, the first electromagnetic directional valve 100 is switched to the second state, and the second electromagnetic directional valve 300 and the third electromagnetic directional valve A 420 are powered, so that the hydraulic oil in the hydraulic pump 200 can first enter the fourth oil port d of the first electromagnetic directional valve 100 through the first oil port a of the first electromagnetic directional valve 100, then enter the rod cavity of the first oil cylinder 410 through the second pipeline 820 communicated with the fourth oil port d of the first electromagnetic directional valve 100, and the hydraulic oil in the rodless cavity of the first oil cylinder 410 can first enter the first pipeline 810, then enter the first electromagnetic directional valve 100 through the third oil port c of the first electromagnetic directional valve 100 communicated with the first pipeline 810, and finally enter the tank 210 through the second oil port b of the first electromagnetic directional valve 100 communicated with the third oil port c of the first electromagnetic directional valve 100, so that the piston of the first oil cylinder 410 can be retracted. In this process, the hydraulic oil in the rodless cavity of the first oil cylinder 410 can enter the third oil port c of the first electromagnetic directional valve 100 in turn through the second oil port h of the third electromagnetic directional valve A 420, the first oil port g of the third electromagnetic directional valve A 420, the second oil port f of the second electromagnetic directional valve 300 and the first oil port e of the second electromagnetic directional valve 300 when flowing through the first pipeline 810.

[0073] Referring to Figures 1 to 3As shown, it can be understood that the outrigger hydraulic control system further comprises a third pipeline 830 and a fourth pipeline 840, one end of the third pipeline 830 communicates with the rodless chamber of the second oil cylinder 510, the other end of the third pipeline 830 communicates with the pipeline between the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve A 420 of the first pipeline 810, the third electromagnetic reversing valve B 520 is arranged on the third pipeline 830, one end of the fourth pipeline 840 communicates with the rod chamber of the second oil cylinder 510, the other end of the fourth pipeline 840 communicates with the fourth oil port d of the first electromagnetic reversing valve 100; wherein, in the case that the first electromagnetic reversing valve 100 is in the first state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve B 520 are all powered on, the hydraulic oil in the hydraulic pump 200 can enter into the rodless chamber of the second oil cylinder 510 in turn through the first oil port a of the first electromagnetic reversing valve 100, the third oil port c of the first electromagnetic reversing valve 100, the first pipeline 810 and the third pipeline 830, the hydraulic oil in the rod chamber of the second oil cylinder 510 can enter into the oil tank 210 in turn through the fourth pipeline 840, the fourth oil port d of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100, in the case that the first electromagnetic reversing valve 100 is in the second state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve B 520 are all powered on, the hydraulic oil in the hydraulic pump 200 can enter into the rod chamber of the second oil cylinder 510 in turn through the first oil port a of the first electromagnetic reversing valve 100, the fourth oil port d of the first electromagnetic reversing valve 100 and the fourth pipeline 840, the hydraulic oil in the rodless chamber of the second oil cylinder 510 can enter into the oil tank 210 in turn through the third pipeline 830, the first pipeline 810, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100.

[0074] When the aerial work platform needs to be lifted, the second oil cylinder 510 needs to be extended. That is, the first electromagnetic directional valve 100 is switched to the first state, and the second electromagnetic directional valve 300 and the third electromagnetic directional valve B520 are powered, so that the hydraulic oil in the hydraulic pump 200 can first enter the first pipeline 810 communicated with the first oil port a of the first electromagnetic directional valve 100 and the third oil port c of the first electromagnetic directional valve 100, and then enter the rodless cavity of the second oil cylinder 510 through the third pipeline 830 communicated with the first pipeline 810. The hydraulic oil in the rod cavity of the second oil cylinder 510 can first enter the fourth pipeline 840, and then enter the first electromagnetic directional valve 100 through the fourth oil port d of the first electromagnetic directional valve 100 communicated with the fourth pipeline 840, and finally enter the tank 210 through the second oil port b of the first electromagnetic directional valve 100 communicated with the fourth oil port d of the first electromagnetic directional valve 100, so that the piston of the second oil cylinder 510 can be extended. In this process, the hydraulic oil in the hydraulic pump 200 can pass through the first oil port e of the second electromagnetic directional valve 300 and the second oil port f of the second electromagnetic directional valve 300 in turn when flowing through the first pipeline 810, and the hydraulic oil in the hydraulic pump 200 can pass through the first oil port i of the third electromagnetic directional valve B520 and the second oil port j of the third electromagnetic directional valve B520 in turn when flowing through the third pipeline 830, and finally enter the rodless cavity of the second oil cylinder 510.

[0075] When it is needed to lower the aerial work platform, the second oil cylinder 510 needs to be retracted. That is, the first electromagnetic directional valve 100 is switched to the second state, and the second electromagnetic directional valve 300 and the third electromagnetic directional valve B520 are electrified, so that the hydraulic oil in the hydraulic pump 200 can first enter the fourth oil port d of the first electromagnetic directional valve 100 through the first oil port a of the first electromagnetic directional valve 100, and then enter the rod cavity of the second oil cylinder 510 through the fourth pipeline 840 communicated with the fourth oil port d of the first electromagnetic directional valve 100. The hydraulic oil in the rodless cavity of the second oil cylinder 510 can pass through the third pipeline 830 and the first pipeline 810 in turn, and then enter the first electromagnetic directional valve 100 through the third oil port c of the first electromagnetic directional valve 100, and finally enter the tank 210 through the second oil port b of the first electromagnetic directional valve 100 communicated with the third oil port c of the first electromagnetic directional valve 100, so that the piston of the second oil cylinder 510 can be retracted. In this process, when the hydraulic oil in the rodless cavity of the second oil cylinder 510 flows through the third pipeline 830, it can pass through the second oil port j of the third electromagnetic directional valve B520 and the first oil port i of the third electromagnetic directional valve B520 in turn, and when the hydraulic oil in the rodless cavity of the second oil cylinder 510 flows through the first pipeline 810, it can pass through the second oil port f of the second electromagnetic directional valve 300 and the first oil port e of the second electromagnetic directional valve 300 in turn, and finally enter the third oil port c of the first electromagnetic directional valve 100.

[0076] With reference to Figures 1 to 3As shown, it can be understood that the outrigger hydraulic control system further comprises a fifth pipeline 850 and a sixth pipeline 860, one end of the fifth pipeline 850 is in communication with the rodless chamber of the third oil cylinder 610, the other end of the fifth pipeline 850 is in communication with the pipeline between the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve A 420 of the first pipeline 810, the third electromagnetic reversing valve C 620 is arranged on the fifth pipeline 850, one end of the sixth pipeline 860 is in communication with the rod chamber of the third oil cylinder 610, the other end of the sixth pipeline 860 is in communication with the fourth oil port d of the first electromagnetic reversing valve 100; wherein, in the case that the first electromagnetic reversing valve 100 is in the first state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve C 620 are all powered on, the hydraulic oil in the hydraulic pump 200 can enter into the rodless chamber of the third oil cylinder 610 in turn through the first oil port a of the first electromagnetic reversing valve 100, the third oil port c of the first electromagnetic reversing valve 100, the first pipeline 810 and the fifth pipeline 850, the hydraulic oil in the rod chamber of the third oil cylinder 610 can enter into the oil tank 210 in turn through the sixth pipeline 860, the fourth oil port d of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100, in the case that the first electromagnetic reversing valve 100 is in the second state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve C 620 are all powered on, the hydraulic oil in the hydraulic pump 200 can enter into the rod chamber of the third oil cylinder 610 in turn through the first oil port a of the first electromagnetic reversing valve 100, the fourth oil port d of the first electromagnetic reversing valve 100 and the sixth pipeline 860, the hydraulic oil in the rodless chamber of the third oil cylinder 610 can enter into the oil tank 210 in turn through the fifth pipeline 850, the first pipeline 810, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100.

[0077] When the aerial work platform needs to be lifted, the third oil cylinder 610 needs to be extended. That is, the first electromagnetic reversing valve 100 is switched to the first state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve C620 are powered, so that the hydraulic oil in the hydraulic pump 200 can first enter the first pipeline 810 communicated with the third oil port c of the first electromagnetic reversing valve 100 through the first oil port a of the first electromagnetic reversing valve 100 and the third oil port c of the first electromagnetic reversing valve 100, and then enter the rodless cavity of the third oil cylinder 610 through the fifth pipeline 850 communicated with the first pipeline 810. The hydraulic oil in the rod cavity of the third oil cylinder 610 can first enter the sixth pipeline 860, and then enter the first electromagnetic reversing valve 100 through the fourth oil port d of the first electromagnetic reversing valve 100 communicated with the sixth pipeline 860, and finally enter the tank 210 through the second oil port b of the first electromagnetic reversing valve 100 communicated with the fourth oil port d of the first electromagnetic reversing valve 100, so that the piston of the third oil cylinder 610 can be extended. In this process, the hydraulic oil in the hydraulic pump 200 can pass through the first oil port e of the second electromagnetic reversing valve 300 and the second oil port f of the second electromagnetic reversing valve 300 in turn when flowing through the first pipeline 810, and the hydraulic oil in the hydraulic pump 200 can pass through the first oil port k of the third electromagnetic reversing valve C620 and the second oil port m of the third electromagnetic reversing valve C620 in turn when flowing through the fifth pipeline 850, and finally enter the rodless cavity of the third oil cylinder 610.

[0078] When it is needed to lower the aerial work platform, the third oil cylinder 610 needs to be retracted. That is, the first electromagnetic reversing valve 100 is switched to the second state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve C620 are electrified, so that the hydraulic oil in the hydraulic pump 200 can first enter the fourth oil port d of the first electromagnetic reversing valve 100 through the first oil port a of the first electromagnetic reversing valve 100, and then enter the rod cavity of the third oil cylinder 610 through the sixth pipeline 860 communicated with the fourth oil port d of the first electromagnetic reversing valve 100. The hydraulic oil in the rodless cavity of the third oil cylinder 610 can pass through the fifth pipeline 850 and the first pipeline 810 in turn, and then enter the first electromagnetic reversing valve 100 through the third oil port c of the first electromagnetic reversing valve 100, and finally enter the tank 210 through the second oil port b of the first electromagnetic reversing valve 100 communicated with the third oil port c of the first electromagnetic reversing valve 100, so that the piston of the third oil cylinder 610 can be retracted. In this process, when the hydraulic oil in the rodless cavity of the third oil cylinder 610 flows through the fifth pipeline 850, it can pass through the second oil port m of the third electromagnetic reversing valve C620 and the first oil port k of the third electromagnetic reversing valve C620 in turn. When the hydraulic oil in the rodless cavity of the third oil cylinder 610 flows through the first pipeline 810, it can pass through the second oil port f of the second electromagnetic reversing valve 300 and the first oil port e of the second electromagnetic reversing valve 300 in turn, and finally enter the third oil port c of the first electromagnetic reversing valve 100.

[0079] Referring to Figures 1 to 3As shown, it can be understood that the outrigger hydraulic control system further comprises a seventh pipeline 870 and an eighth pipeline 880, one end of the seventh pipeline 870 is in communication with the rodless cavity of the fourth oil cylinder 710, the other end of the seventh pipeline 870 is in communication with the pipeline between the first pipeline 810 and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve A 420, the third electromagnetic reversing valve D 720 is arranged on the seventh pipeline 870, one end of the eighth pipeline 880 is in communication with the rod cavity of the fourth oil cylinder 710, the other end of the eighth pipeline 880 is in communication with the fourth oil port d of the first electromagnetic reversing valve 100; wherein, in the case that the first electromagnetic reversing valve 100 is in the first state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve D 720 are all powered on, the hydraulic oil in the hydraulic pump 200 can enter the rodless cavity of the fourth oil cylinder 710 in turn through the first oil port a of the first electromagnetic reversing valve 100, the third oil port c of the first electromagnetic reversing valve 100, the first pipeline 810 and the seventh pipeline 870, the hydraulic oil in the rod cavity of the fourth oil cylinder 710 can enter the oil tank 210 in turn through the eighth pipeline 880, the fourth oil port d of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100, in the case that the first electromagnetic reversing valve 100 is in the second state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve D 720 are all powered on, the hydraulic oil in the hydraulic pump 200 can enter the rod cavity of the fourth oil cylinder 710 in turn through the first oil port a of the first electromagnetic reversing valve 100, the fourth oil port d of the first electromagnetic reversing valve 100 and the eighth pipeline 880, the hydraulic oil in the rodless cavity of the fourth oil cylinder 710 can enter the oil tank 210 in turn through the seventh pipeline 870, the first pipeline 810, the third oil port c of the first electromagnetic reversing valve 100 and the second oil port b of the first electromagnetic reversing valve 100.

[0080] When the aerial work platform needs to be lifted, the fourth oil cylinder 710 needs to be extended. That is, the first electromagnetic reversing valve 100 is switched to the first state, and the second electromagnetic reversing valve 300 and the third electromagnetic reversing valve D720 are powered, so that the hydraulic oil in the hydraulic pump 200 can first enter the first pipeline 810 communicated with the third oil port c of the first electromagnetic reversing valve 100 through the first oil port a of the first electromagnetic reversing valve 100 and the third oil port c of the first electromagnetic reversing valve 100, and then enter the rodless cavity of the fourth oil cylinder 710 through the seventh pipeline 870 communicated with the first pipeline 810. The hydraulic oil in the rod cavity of the fourth oil cylinder 710 can first enter the eighth pipeline 880, and then enter the first electromagnetic reversing valve 100 through the fourth oil port d of the first electromagnetic reversing valve 100 communicated with the eighth pipeline 880, and finally enter the tank 210 through the second oil port b of the first electromagnetic reversing valve 100 communicated with the fourth oil port d of the first electromagnetic reversing valve 100, so that the piston of the fourth oil cylinder 710 can be extended. In this process, the hydraulic oil in the hydraulic pump 200 can pass through the first oil port e of the second electromagnetic reversing valve 300 and the second oil port f of the second electromagnetic reversing valve 300 in turn when flowing through the first pipeline 810, and the hydraulic oil in the hydraulic pump 200 can pass through the first oil port n of the third electromagnetic reversing valve D720 and the second oil port p of the third electromagnetic reversing valve D720 in turn when flowing through the seventh pipeline 870, and finally enter the rodless cavity of the fourth oil cylinder 710.

[0081] When it is necessary to lower the aerial work platform, the fourth cylinder 710 needs to be retracted. The first solenoid directional valve 100 can be switched to the second state, and the second solenoid directional valve 300 and the third solenoid directional valve D720 can be energized. Then, the hydraulic oil in the hydraulic pump 200 can first enter the fourth port d of the first solenoid directional valve 100 through the first port a, and then enter the rod chamber of the fourth cylinder 710 through the eighth pipeline 880 connected to the fourth port d of the first solenoid directional valve 100. The hydraulic oil in the rodless chamber of the fourth cylinder 710 can sequentially pass through the seventh pipeline 870 and the first pipeline 810, and then enter the first solenoid directional valve 100 through the third port c of the first solenoid directional valve 100 connected to the first pipeline 810. Finally, it enters the oil tank 210 through the second port b of the first solenoid directional valve 100 connected to the third port c of the first solenoid directional valve 100, thereby enabling the piston of the fourth cylinder 710 to retract. During this process, the hydraulic oil in the rodless chamber of the fourth cylinder 710, when flowing through the seventh pipeline 870, can sequentially pass through the second port p and the first port n of the third solenoid directional valve D720. The hydraulic oil in the rodless chamber of the fourth cylinder 710, when flowing through the first pipeline 810, can sequentially pass through the second port f and the first port e of the second solenoid directional valve 300, and finally enter the third port c of the first solenoid directional valve 100.

[0082] Reference Figure 1 as well as Figure 2 As shown, a control method for a hydraulic control system for outriggers according to an embodiment of the present invention includes: in a first case:

[0083] S100: The drive source 220 is energized, causing it to drive the hydraulic pump 200 to output hydraulic oil; the first solenoid directional valve 100 is energized, switching it to its first state; the second solenoid directional valve 300 is energized, connecting its first port e to its second port f; the third solenoid directional valve of each cylinder unit is energized, connecting its first port to its second port, so that the hydraulic oil in the hydraulic pump 200 passes through the first solenoid valve sequentially. The first port a of the magnetic directional valve 100, the third port c of the first electromagnetic directional valve 100, the first port e of the second electromagnetic directional valve 300, the second port f of the second electromagnetic directional valve 300, the first port of the third electromagnetic directional valve of each cylinder unit, and the second port of the third electromagnetic directional valve of each cylinder unit enter the rodless chamber of the cylinder of each cylinder unit, and cause the hydraulic oil in the rod chamber of the cylinder of each cylinder unit to sequentially pass through the fourth port d of the first electromagnetic directional valve 100 and the second port b of the first electromagnetic directional valve 100 into the oil tank 210.

[0084] S200, controlling the driving source 220 and the third electromagnetic directional control valve of each oil cylinder unit to lose power, so that the oil cylinder of each oil cylinder unit is locked.

[0085] S300, controlling the second electromagnetic directional control valve 300 and the first electromagnetic directional control valve 100 to lose power within a preset time when the driving source 220 and the third electromagnetic directional control valve of each oil cylinder unit lose power.

[0086] Specifically, the first case is the case that the piston of the oil cylinder of each oil cylinder unit is extended, i.e. the case that the aerial work platform is lifted.

[0087] Further, when the operation key 240, which can be a handle or a button, is pressed to transmit a signal to the controller 230, the controller 230 controls the DT1 of the first electromagnetic directional control valve 100 to be powered on, the first electromagnetic directional control valve 100 switches to the first state; when the operation key 240 is pressed to transmit a signal to the controller 230, the controller 230 controls the DT3 of the second electromagnetic directional control valve 300 to be powered on, the first oil port e of the second electromagnetic directional control valve 300 communicates with the second oil port f of the second electromagnetic directional control valve 300; when the operation key 240 is pressed to transmit a signal to the controller 230, the controller 230 controls the DT4 of the third electromagnetic directional control valve of each oil cylinder unit to be powered on, the first oil port of the third electromagnetic directional control valve of each oil cylinder unit communicates with the second oil port of the third electromagnetic directional control valve of each oil cylinder unit.

[0088] Further, in one embodiment, the second electromagnetic directional control valve 300 and the first electromagnetic directional control valve 100 are controlled to lose power within a preset time when the driving source 220 and the third electromagnetic directional control valve of each oil cylinder unit lose power, i.e. within 1s to 2s when the driving source 220 and the third electromagnetic directional control valve of each oil cylinder unit lose power, in addition to this, in other embodiments, different preset times can be determined according to different working conditions.

[0089] It should be noted that, in the case that the oil cylinder of each oil cylinder unit is locked, the pipe maintenance port is Figure 1 and Figure 2 the V1 port between the second electromagnetic directional control valve 300 and the third electromagnetic directional control valve of each oil cylinder unit.

[0090] In the control method of the outrigger hydraulic control system, the driving source 220 is controlled to be powered on, so that the driving source 220 drives the hydraulic pump 200 to output hydraulic oil; the first electromagnetic directional valve 100 is controlled to be powered on, so that the first electromagnetic directional valve 100 is switched to the first state; and the second electromagnetic directional valve 300 and the third electromagnetic directional valve of each cylinder unit are controlled to be powered on, so that the hydraulic oil in the hydraulic pump 200 sequentially passes through the first electromagnetic directional valve 100, the second electromagnetic directional valve 300, and the third electromagnetic directional valve of each cylinder unit, and then enters the rodless chamber of the cylinder of each cylinder unit, and the hydraulic oil in the rod chamber of the cylinder of each cylinder unit passes through the first electromagnetic directional valve 100 and then enters the oil tank 210. Thus, when the first electromagnetic directional valve 100 is in the first state and the second electromagnetic directional valve 300 and the third electromagnetic directional valve of each cylinder unit are powered on, the cylinder of each cylinder unit can be extended, so as to realize the lifting of the aerial work platform. In this process, the hydraulic oil in the hydraulic pump 200 sequentially passes through the first oil port a of the first electromagnetic directional valve 100, the third oil port c of the first electromagnetic directional valve 100, the first oil port e of the second electromagnetic directional valve 300, the second oil port f of the second electromagnetic directional valve 300, the first oil port of the third electromagnetic directional valve of each cylinder unit, and the second oil port of the third electromagnetic directional valve of each cylinder unit, and then enters the rodless chamber of the cylinder of each cylinder unit; and the hydraulic oil in the rod chamber of the cylinder of each cylinder unit sequentially passes through the fourth oil port d of the first electromagnetic directional valve 100 and the second oil port b of the first electromagnetic directional valve 100, and then enters the oil tank 210.

[0091] When the aerial work platform is lifted to the preset height, the driving source 220 and the third electromagnetic directional valve of each cylinder unit are controlled to be powered off, so that the driving source 220 and the third electromagnetic directional valve of each cylinder unit are switched to the off state, and the cylinder of each cylinder unit is locked.

[0092] In the preset time when the driving source 220 and the third electromagnetic directional valve of each cylinder unit are powered off, the second electromagnetic directional valve 300 and the first electromagnetic directional valve 100 are controlled to be powered off, that is, the second electromagnetic directional valve 300 and the first electromagnetic directional valve 100 are powered off in the case that the driving source 220 and the third electromagnetic directional valve of each cylinder unit are powered off. In this way, in the case that the driving source 220 and the third electromagnetic directional valve of each cylinder unit are powered off, the pressure of the hydraulic oil in the pipeline connecting the second electromagnetic directional valve 300 and the third electromagnetic directional valve of each cylinder unit can be reduced, so that the hydraulic oil in the pipeline can be prevented from being sprayed to the outside from the pipeline when the pipeline is maintained, and the safety during the maintenance of the pipeline is improved.

[0093] Referring to Figure 1 and Figure 3As shown, the control method of the outrigger hydraulic control system of an embodiment of the present application comprises the following steps:

[0094] H100, controlling the driving source 220 to be powered on, so that the driving source 220 drives the hydraulic pump 200 to output hydraulic oil; controlling the first electromagnetic directional valve 100 to be powered on, so that the first electromagnetic directional valve 100 switches to the second state; controlling the second electromagnetic directional valve 300 to be powered on, so that the first oil port e of the second electromagnetic directional valve 300 communicates with the second oil port f of the second electromagnetic directional valve 300; and controlling the third electromagnetic directional valve of each oil cylinder unit to be powered on, so that the first oil port of the third electromagnetic directional valve communicates with the second oil port of the third electromagnetic directional valve, so that the hydraulic oil in the hydraulic pump 200 enters the rod cavity of the oil cylinder of each oil cylinder unit through the first oil port a of the first electromagnetic directional valve 100 and the fourth oil port d of the first electromagnetic directional valve 100 in sequence, and the hydraulic oil in the rodless cavity of the oil cylinder of each oil cylinder unit enters the oil tank 210 through the second oil port f of the second electromagnetic directional valve 300, the first oil port e of the second electromagnetic directional valve 300, the third oil port c of the first electromagnetic directional valve 100, and the second oil port b of the first electromagnetic directional valve 100 in sequence.

[0095] H200, controlling the driving source 220 and the third electromagnetic directional valve of each oil cylinder unit to be powered off, so that the oil cylinder of each oil cylinder unit is locked.

[0096] H300, controlling the second electromagnetic directional valve 300 and the first electromagnetic directional valve 100 to be powered off within a preset time when the driving source 220 and the third electromagnetic directional valve of each oil cylinder unit are powered off.

[0097] Specifically, the second case is the case that the piston of the oil cylinder of each oil cylinder unit is retracted, i.e., the case that the aerial work platform is lowered.

[0098] Further, when the operation key 240, which can be a handle or a button, is pressed to transmit a signal to the controller 230, the controller 230 controls the DT2 of the first electromagnetic directional valve 100 to be powered on, so that the first electromagnetic directional valve 100 switches to the second state; when the operation key 240 is pressed to transmit a signal to the controller 230, the controller 230 controls the DT3 of the second electromagnetic directional valve 300 to be powered on, so that the first oil port e of the second electromagnetic directional valve 300 communicates with the second oil port f of the second electromagnetic directional valve 300; and when the operation key 240 is pressed to transmit a signal to the controller 230, the controller 230 controls the DT4 of the third electromagnetic directional valve of each oil cylinder unit to be powered on, so that the first oil port of the third electromagnetic directional valve of each oil cylinder unit communicates with the second oil port of the third electromagnetic directional valve of each oil cylinder unit.

[0099] Further, in one embodiment, the second electromagnetic directional valve 300 and the first electromagnetic directional valve 100 are controlled to be de-energized within a preset time in which the driving source 220 and the third electromagnetic directional valve of each oil cylinder unit are de-energized, i.e. within 1s to 2s in which the driving source 220 and the third electromagnetic directional valve of each oil cylinder unit are de-energized. In other embodiments, different preset times can be determined according to different working conditions.

[0100] It should be noted that, in the case that the oil cylinder of each oil cylinder unit is locked, the pipe maintenance opening is V2 in the first electromagnetic directional valve 100 and the rod cavity of the oil cylinder of each oil cylinder unit. Figure 1 and Figure 3 V2 is located between the first electromagnetic directional valve 100 and the rod cavity of the oil cylinder of each oil cylinder unit.

[0101] In the control method of the above-mentioned outrigger hydraulic control system, the driving source 220 is controlled to be energized, so that the driving source 220 drives the hydraulic pump 200 to output hydraulic oil. The first electromagnetic directional valve 100 is controlled to be energized, so that the first electromagnetic directional valve 100 is switched to the second state. The second electromagnetic directional valve 300 and the third electromagnetic directional valve of each oil cylinder unit are controlled to be energized, so that the hydraulic oil in the hydraulic pump 200 enters the rod cavity of the oil cylinder of each oil cylinder unit through the first electromagnetic directional valve 100, and the hydraulic oil in the rodless cavity of the oil cylinder of each oil cylinder unit enters the tank 210 through the third electromagnetic directional valve of each oil cylinder unit, the second electromagnetic directional valve 300 and the first electromagnetic directional valve 100 in turn. Thus, in the case that the first electromagnetic directional valve 100 is in the second state and the second electromagnetic directional valve 300 and the third electromagnetic directional valve of each oil cylinder unit are all energized, the oil cylinder of each oil cylinder unit can be contracted, so as to realize the lowering of the aerial work platform. In this process, the hydraulic oil in the hydraulic pump 200 can enter the rod cavity of the oil cylinder of each oil cylinder unit through the first oil port a of the first electromagnetic directional valve 100 and the fourth oil port d of the first electromagnetic directional valve 100 in turn. The hydraulic oil in the rodless cavity of the oil cylinder of each oil cylinder unit can enter the tank 210 through the second oil port of the third electromagnetic directional valve of each oil cylinder unit, the first oil port of the third electromagnetic directional valve of each oil cylinder unit, the second oil port f of the second electromagnetic directional valve 300, the first oil port e of the second electromagnetic directional valve 300, the third oil port c of the first electromagnetic directional valve 100 and the second oil port b of the first electromagnetic directional valve 100 in turn.

[0102] When the above-mentioned aerial work platform is lowered to a preset height, the driving source 220 and the third electromagnetic directional valve of each oil cylinder unit are controlled to be de-energized, so that the driving source 220 and the third electromagnetic directional valve of each oil cylinder unit are switched to the open state, i.e. the oil cylinder of each oil cylinder unit is locked.

[0103] In the preset time when the driving source 220 and the third electromagnetic switching valve of each oil cylinder unit lose electricity, the second electromagnetic switching valve 300 and the first electromagnetic switching valve 100 lose electricity, that is, the second electromagnetic switching valve 300 and the first electromagnetic switching valve 100 lose electricity in a delay manner when the driving source 220 and the third electromagnetic switching valve of each oil cylinder unit lose electricity. In this way, when the driving source 220 and the third electromagnetic switching valve of each oil cylinder unit lose electricity, the pressure of the hydraulic oil in the pipeline connected between the first electromagnetic switching valve 100 and the rod cavity of each oil cylinder unit can be reduced, so that the hydraulic oil in the pipeline can be prevented from being sprayed to the outside from the pipeline when the pipeline is overhauled, thereby improving the safety when the pipeline is overhauled.

[0104] In addition, when the aerial work platform starts to descend, that is, the piston of the oil cylinder of each oil cylinder unit starts to contract, the second electromagnetic switching valve 300, the third electromagnetic switching valve of each oil cylinder unit and the first electromagnetic switching valve 100 do not switch the on-off state quickly due to the sudden change of the pressure of the hydraulic oil after being powered on, so that when the piston of the oil cylinder of each oil cylinder unit starts to contract, the oil cylinder can be prevented from emitting a whistling abnormal sound and high-frequency vibration, thereby improving the stability of the outrigger oil cylinder during movement.

[0105] The aerial work platform of one embodiment of the present application comprises the outrigger hydraulic control system described above or the control method applied to the outrigger hydraulic control system described above.

[0106] In the aerial work platform described above, the outrigger hydraulic control system described above can improve the stability of the outrigger oil cylinder during movement when the aerial work platform starts to descend, so that the aerial work platform described above has good stability during lifting and descending. In addition, the outrigger hydraulic control system described above can lock the oil cylinder of each oil cylinder unit, so that the aerial work platform described above has good safety when working at a preset height.

[0107] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. A control method of a hydraulic outrigger control system, characterized by, The application is applied to a support leg hydraulic control system, and the support leg hydraulic control system comprises: a first electromagnetic directional valve, a first oil port of the first electromagnetic directional valve is used for being communicated with a hydraulic pump, a second oil port of the first electromagnetic directional valve is used for being communicated with an oil tank, in a case where the first electromagnetic directional valve is in a first state, the first oil port of the first electromagnetic directional valve is communicated with a third oil port of the first electromagnetic directional valve, and a fourth oil port of the first electromagnetic directional valve is communicated with the second oil port of the first electromagnetic directional valve, in a case where the first electromagnetic directional valve is in a second state, the first oil port of the first electromagnetic directional valve is communicated with a fourth oil port of the first electromagnetic directional valve, and the third oil port of the first electromagnetic directional valve is communicated with the second oil port of the first electromagnetic directional valve; a second electromagnetic directional valve, a first oil port of the second electromagnetic directional valve is communicated with the third oil port of the first electromagnetic directional valve; a cylinder assembly, the cylinder assembly comprises a plurality of cylinder units, each of the cylinder units comprises a cylinder and a third electromagnetic directional valve, a first oil port of each of the third electromagnetic directional valves is communicated with a second oil port of the second electromagnetic directional valve, a rod cavity of each of the cylinders is communicated with the fourth oil port of the first electromagnetic directional valve, and in each of the cylinder units, a second oil port of the third electromagnetic directional valve is communicated with a rodless cavity of the cylinder; wherein the second electromagnetic directional valve is located between the third electromagnetic directional valve and the first electromagnetic directional valve; a control method of the support leg hydraulic control system comprises: in a first case: controlling a driving source to be powered on, so that the driving source drives the hydraulic pump to output hydraulic oil; controlling the first electromagnetic directional valve to be powered on, so that the first electromagnetic directional valve is switched to the first state; controlling the second electromagnetic directional valve to be powered on, so that the first oil port of the second electromagnetic directional valve is communicated with the second oil port of the second electromagnetic directional valve; controlling the third electromagnetic directional valve of each of the cylinder units to be powered on, so that the first oil port of the third electromagnetic directional valve is communicated with the second oil port of the third electromagnetic directional valve, so that the hydraulic oil in the hydraulic pump sequentially passes through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first oil port of the second electromagnetic directional valve, the second oil port of the second electromagnetic directional valve, the first oil port of the third electromagnetic directional valve of each of the cylinder units, and the second oil port of the third electromagnetic directional valve of each of the cylinder units, and enters the rodless cavity of the cylinder of each of the cylinder units, and the hydraulic oil in the rod cavity of the cylinder of each of the cylinder units sequentially passes through the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve, and enters the oil tank; controlling the driving source and the third electromagnetic directional valve of each of the cylinder units to be powered off, so that the cylinder of each of the cylinder units is locked; In a preset time when the driving source and the third electromagnetic switching valve of each oil cylinder unit lose power, the second electromagnetic switching valve and the first electromagnetic switching valve are controlled to lose power, and in the case that the driving source and the third electromagnetic switching valve of each oil cylinder unit lose power, the second electromagnetic switching valve and the first electromagnetic switching valve are controlled to lose power with delay. In the second case: The driving source is controlled to be powered on, so that the driving source drives the hydraulic pump to output hydraulic oil; The first electromagnetic switching valve is controlled to be powered on, so that the first electromagnetic switching valve is switched to the second state; The second electromagnetic switching valve is controlled to be powered on, so that the first oil port of the second electromagnetic switching valve communicates with the second oil port of the second electromagnetic switching valve; The third electromagnetic switching valve of each oil cylinder unit is controlled to be powered on, so that the first oil port of the third electromagnetic switching valve communicates with the second oil port of the third electromagnetic switching valve, so that the hydraulic oil in the hydraulic pump enters the rod cavity of each oil cylinder unit through the first oil port of the first electromagnetic switching valve and the fourth oil port of the first electromagnetic switching valve in turn, and the hydraulic oil in the rodless cavity of each oil cylinder unit enters the oil tank through the second oil port of the third electromagnetic switching valve of each oil cylinder unit, the first oil port of the third electromagnetic switching valve of each oil cylinder unit, the second oil port of the second electromagnetic switching valve, the first oil port of the second electromagnetic switching valve, the third oil port of the first electromagnetic switching valve, and the second oil port of the first electromagnetic switching valve in turn; The driving source and the third electromagnetic switching valve of each oil cylinder unit are controlled to lose power, so that the oil cylinder of each oil cylinder unit is locked; In a preset time when the driving source and the third electromagnetic switching valve of each oil cylinder unit lose power, the second electromagnetic switching valve and the first electromagnetic switching valve are controlled to lose power, and in the case that the driving source and the third electromagnetic switching valve of each oil cylinder unit lose power, the second electromagnetic switching valve and the first electromagnetic switching valve are controlled to lose power with delay.

2. The control method of the outrigger hydraulic control system according to claim 1, characterized by, In the case that the first electromagnetic reversing valve is in the first state, and the second electromagnetic reversing valve and the third electromagnetic reversing valve are powered, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the oil cylinder in sequence through the first oil port of the first electromagnetic reversing valve, the third oil port of the first electromagnetic reversing valve, the first oil port of the second electromagnetic reversing valve, the second oil port of the second electromagnetic reversing valve, the first oil port of the third electromagnetic reversing valve and the second oil port of the third electromagnetic reversing valve, and the hydraulic oil in the rod chamber of the oil cylinder can enter into the oil tank in sequence through the fourth oil port of the first electromagnetic reversing valve and the second oil port of the first electromagnetic reversing valve, in the case that the first electromagnetic reversing valve is in the second state, and the second electromagnetic reversing valve and the third electromagnetic reversing valve are powered, the hydraulic oil in the hydraulic pump can enter into the rod chamber of the oil cylinder in sequence through the first oil port of the first electromagnetic reversing valve and the fourth oil port of the first electromagnetic reversing valve, and the hydraulic oil in the rodless chamber of the oil cylinder can enter into the oil tank in sequence through the second oil port of the third electromagnetic reversing valve, the first oil port of the third electromagnetic reversing valve, the second oil port of the second electromagnetic reversing valve, the first oil port of the second electromagnetic reversing valve, the third oil port of the first electromagnetic reversing valve and the second oil port of the first electromagnetic reversing valve.

3. The control method of the outrigger hydraulic control system according to claim 2, characterized by, The plurality of oil cylinder units comprise a first oil cylinder unit, a second oil cylinder unit, a third oil cylinder unit and a fourth oil cylinder unit, the first oil cylinder unit comprises a first oil cylinder and a third electromagnetic reversing valve A, the second oil cylinder unit comprises a second oil cylinder and a third electromagnetic reversing valve B, the third oil cylinder unit comprises a third oil cylinder and a third electromagnetic reversing valve C, and the fourth oil cylinder unit comprises a fourth oil cylinder and a third electromagnetic reversing valve D. The rodless chamber of the first oil cylinder is in communication with the second oil port of the third electromagnetic reversing valve A, the rodless chamber of the second oil cylinder is in communication with the second oil port of the third electromagnetic reversing valve B, the rodless chamber of the third oil cylinder is in communication with the second oil port of the third electromagnetic reversing valve C, the rodless chamber of the fourth oil cylinder is in communication with the second oil port of the third electromagnetic reversing valve D, and the first oil port of the third electromagnetic reversing valve A, the first oil port of the third electromagnetic reversing valve B, the first oil port of the third electromagnetic reversing valve C and the first oil port of the third electromagnetic reversing valve D are in communication with the second oil port of the second electromagnetic reversing valve, and the rod chamber of the first oil cylinder, the rod chamber of the second oil cylinder, the rod chamber of the third oil cylinder and the rod chamber of the fourth oil cylinder are in communication with the fourth oil port of the first electromagnetic reversing valve.

4. The control method of the outrigger hydraulic control system according to claim 3, characterized by, The outrigger hydraulic control system further comprises a first pipeline and a second pipeline, one end of the first pipeline is communicated with the rodless cavity of the first oil cylinder, the other end of the first pipeline is communicated with the third oil port of the first electromagnetic directional valve, the second electromagnetic directional valve and the third electromagnetic directional valve A are arranged on the first pipeline, one end of the second pipeline is communicated with the rod cavity of the first oil cylinder, the other end of the second pipeline is communicated with the fourth oil port of the first electromagnetic directional valve; Wherein, in the case that the first electromagnetic directional valve is in the first state, and the second electromagnetic directional valve and the third electromagnetic directional valve A are powered on, the hydraulic oil in the hydraulic pump can enter into the rodless cavity of the first oil cylinder through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve and the first pipeline in turn, the hydraulic oil in the rod cavity of the first oil cylinder can enter into the oil tank through the second pipeline, the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in turn, in the case that the first electromagnetic directional valve is in the second state, and the second electromagnetic directional valve and the third electromagnetic directional valve A are powered on, the hydraulic oil in the hydraulic pump can enter into the rod cavity of the first oil cylinder through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve and the second pipeline in turn, the hydraulic oil in the rodless cavity of the first oil cylinder can enter into the oil tank through the first pipeline, the third oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve in turn.

5. The control method of the outrigger hydraulic control system according to claim 4, characterized by, The outrigger hydraulic control system further comprises a third pipeline and a fourth pipeline, one end of the third pipeline is communicated with the rodless cavity of the second oil cylinder, the other end of the third pipeline is communicated with the pipeline between the second electromagnetic directional valve and the third electromagnetic directional valve A of the first pipeline, the third electromagnetic directional valve B is arranged on the third pipeline, one end of the fourth pipeline is communicated with the rod cavity of the second oil cylinder, the other end of the fourth pipeline is communicated with the fourth oil port of the first electromagnetic directional valve; Wherein, in the case that the first electromagnetic directional valve is in the first state, and the second electromagnetic directional valve and the third electromagnetic directional valve A are powered on, the hydraulic oil in the hydraulic pump can enter into the rodless cavity of the second oil cylinder through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve and the third pipeline in turn, the hydraulic oil in the rod cavity of the second oil cylinder can enter into the oil tank through the fourth pipeline, the second oil port of the first electromagnetic directional valve and the second pipeline in turn, in the case that the first electromagnetic directional valve is in the second state, and the second electromagnetic directional valve and the third electromagnetic directional valve A are powered on, the hydraulic oil in the hydraulic pump can enter into the rod cavity of the second oil cylinder through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve and the fourth pipeline in turn, the hydraulic oil in the rodless cavity of the second oil cylinder can enter into the oil tank through the third pipeline, the second oil port of the first electromagnetic directional valve and the second pipeline in turn. Wherein, in the case that the first electromagnetic directional valve is in the first state, and the second electromagnetic directional valve and the third electromagnetic directional valve B are both powered, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the second oil cylinder in sequence through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first pipeline and the third pipeline, the hydraulic oil in the rod chamber of the second oil cylinder can enter into the oil tank in sequence through the fourth pipeline, the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve, in the case that the first electromagnetic directional valve is in the second state, and the second electromagnetic directional valve and the third electromagnetic directional valve B are both powered, the hydraulic oil in the hydraulic pump can enter into the rod chamber of the second oil cylinder in sequence through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve and the fourth pipeline, the hydraulic oil in the rodless chamber of the second oil cylinder can enter into the oil tank in sequence through the third pipeline, the first pipeline, the third oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve.

6. The control method of the outrigger hydraulic control system according to claim 4, characterized by, The outrigger hydraulic control system further comprises a fifth pipeline and a sixth pipeline, one end of the fifth pipeline is in communication with the rodless chamber of the third oil cylinder, the other end of the fifth pipeline is in communication with the pipeline between the second electromagnetic directional valve and the third electromagnetic directional valve A of the first pipeline, the third electromagnetic directional valve C is arranged on the fifth pipeline, one end of the sixth pipeline is in communication with the rod chamber of the third oil cylinder, the other end of the sixth pipeline is in communication with the fourth oil port of the first electromagnetic directional valve; Wherein, in the case that the first electromagnetic directional valve is in the first state, and the second electromagnetic directional valve and the third electromagnetic directional valve C are both powered, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the third oil cylinder in sequence through the first oil port of the first electromagnetic directional valve, the third oil port of the first electromagnetic directional valve, the first pipeline and the fifth pipeline, the hydraulic oil in the rod chamber of the third oil cylinder can enter into the oil tank in sequence through the sixth pipeline, the fourth oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve, in the case that the first electromagnetic directional valve is in the second state, and the second electromagnetic directional valve and the third electromagnetic directional valve C are both powered, the hydraulic oil in the hydraulic pump can enter into the rod chamber of the third oil cylinder in sequence through the first oil port of the first electromagnetic directional valve, the fourth oil port of the first electromagnetic directional valve and the sixth pipeline, the hydraulic oil in the rodless chamber of the third oil cylinder can enter into the oil tank in sequence through the fifth pipeline, the first pipeline, the third oil port of the first electromagnetic directional valve and the second oil port of the first electromagnetic directional valve.

7. The control method of the outrigger hydraulic control system according to claim 4, characterized by, The outrigger hydraulic control system further comprises a seventh pipeline and an eighth pipeline, one end of the seventh pipeline is communicated with the rodless chamber of the fourth oil cylinder, the other end of the seventh pipeline is communicated with the pipeline between the second electromagnetic reversing valve and the third electromagnetic reversing valve A of the first pipeline, the third electromagnetic reversing valve D is arranged on the seventh pipeline, one end of the eighth pipeline is communicated with the rod chamber of the fourth oil cylinder, the other end of the eighth pipeline is communicated with the fourth oil port of the first electromagnetic reversing valve; Wherein, in the case that the first electromagnetic reversing valve is in the first state, and the second electromagnetic reversing valve and the third electromagnetic reversing valve D are powered on, the hydraulic oil in the hydraulic pump can enter into the rodless chamber of the fourth oil cylinder through the first oil port of the first electromagnetic reversing valve, the third oil port of the first electromagnetic reversing valve, the first pipeline and the seventh pipeline in turn, the hydraulic oil in the rod chamber of the fourth oil cylinder can enter into the oil tank through the eighth pipeline, the fourth oil port of the first electromagnetic reversing valve and the second oil port of the first electromagnetic reversing valve in turn, in the case that the first electromagnetic reversing valve is in the second state, and the second electromagnetic reversing valve and the third electromagnetic reversing valve D are powered on, the hydraulic oil in the hydraulic pump can enter into the rod chamber of the fourth oil cylinder through the first oil port of the first electromagnetic reversing valve, the fourth oil port of the first electromagnetic reversing valve and the eighth pipeline in turn, the hydraulic oil in the rodless chamber of the fourth oil cylinder can enter into the oil tank through the seventh pipeline, the first pipeline, the third oil port of the first electromagnetic reversing valve and the second oil port of the first electromagnetic reversing valve in turn.

8. An aerial work platform, characterized by The control method of the outrigger hydraulic control system as claimed in any one of claims 1 to 7 is applied.

Images