Boom hydraulic control system and control method thereof and aerial work vehicle

Abstract

The present invention discloses a boom hydraulic control system, a control method thereof, and an aerial work vehicle. The boom hydraulic control system includes a main oil circuit; a boom luffing oil cylinder; a boom telescopic oil cylinder; a first solenoid valve, wherein a first oil port of the first solenoid valve is connected to an oil tank, and a rod cavity of the boom luffing oil cylinder and a first oil port of the main oil circuit are both connected to a second oil port of the first solenoid valve; a second solenoid valve, wherein a first oil port of the second solenoid valve is connected to an oil tank, and a rodless cavity of the boom telescopic oil cylinder and a second oil port of the main oil circuit are both connected to a second oil port of the second solenoid valve; a slewing platform drive motor; and a third solenoid valve, wherein a first oil port of the third solenoid valve is connected to a third oil port of the main oil circuit, and a second oil port of the third solenoid valve is connected to a first oil port of the slewing platform drive motor; or a first oil port of the third solenoid valve is connected to a fourth oil port of the main oil circuit, and a second oil port of the third solenoid valve is connected to a second oil port of the slewing platform drive motor.

Description

Technical Field

[0001] The present invention relates to the technical field of aerial work, and in particular to a boom hydraulic control system and a control method thereof, as well as an aerial work vehicle. Background Art

[0002] In the field of aerial work technology, manual control of the boom's lifting range, extension length, and rotation angle is often required to prevent the boom from tipping over due to excessive descent, extension, or rotation. Traditional aerial work platforms typically use a multi-way valve with an integrated displacement sensor to limit the boom's descent range, extension length, and rotation angle. However, this method of limiting the boom's descent and extension length is costly, prone to failure, and difficult to install a manual joystick on the aerial work platform to operate the boom. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a boom hydraulic control system that can optimize the control of the boom's lowering range, extension length, and rotation angle.

[0004] The present invention also provides a control method for a boom hydraulic control system having the above boom hydraulic control system.

[0005] The present invention also provides an aerial work platform having the above-mentioned boom hydraulic control system or applying the control method of the above-mentioned boom hydraulic control system.

[0006] The boom hydraulic control system according to the first embodiment of the present invention includes: a main oil circuit; a boom luffing oil cylinder, the boom luffing oil cylinder is used to adjust the angle of the boom relative to the horizontal plane, and the rod chamber of the boom luffing oil cylinder is connected to the first oil port of the main oil circuit; a boom telescopic oil cylinder, the boom telescopic oil cylinder is used to adjust the length of the boom, and the rodless chamber of the boom telescopic oil cylinder is connected to the second oil port of the main oil circuit; a first solenoid valve, the first oil port of the first solenoid valve is used to communicate with the oil tank, and the rod chamber of the boom luffing oil cylinder and the first oil port of the main oil circuit are both connected to the second oil port of the first solenoid valve; a second solenoid valve, The first oil port of the second solenoid valve is used to communicate with the oil tank, and the rodless chamber of the arm telescopic cylinder and the second oil port of the main oil circuit are both connected to the second oil port of the second solenoid valve; the turntable drive motor, the turntable drive motor is used to adjust the rotation angle of the turntable; and the third solenoid valve, the first oil port of the third solenoid valve is connected to the third oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the first oil port of the turntable drive motor; or the first oil port of the third solenoid valve is connected to the fourth oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the second oil port of the turntable drive motor.

[0007] The boom hydraulic control system according to the embodiment of the present invention has at least the following beneficial effects:

[0008] In the above-mentioned boom hydraulic control system, the boom luffing cylinder is used to adjust the angle of the boom relative to the horizontal plane. When the boom luffing cylinder is extended, the boom can be luffed upward, and when the boom luffing cylinder is retracted, the boom can be luffed downward; the boom telescopic cylinder is used to adjust the length of the boom. When the boom telescopic cylinder is extended, the length of the boom can be lengthened, and when the boom telescopic cylinder is retracted, the length of the boom can be shortened; the turntable drive motor is used to adjust the rotation angle of the turntable. The turntable drive motor can drive the turntable to rotate counterclockwise or clockwise, so that the turntable can drive the turntable to rotate counterclockwise or clockwise.

[0009] During the process of the boom being luffed upward or downward, the first solenoid valve is in a normally closed state. When hydraulic oil enters the rod chamber of the boom luffing cylinder from the first oil port of the main oil circuit, the piston of the boom luffing cylinder can contract, allowing the boom to be luffed downward, making the angle between the boom and the horizontal plane smaller and smaller. The smaller the angle between the boom and the horizontal plane, the greater the distance between the center of gravity of the boom and the center of gravity of the aerial work vehicle, and the more likely the aerial work vehicle is to tip over. When the angle between the boom and the horizontal plane reaches the limit angle, the first solenoid valve can be switched to an open state. At this time, the hydraulic oil from the first oil port of the main oil circuit will no longer enter the rod chamber of the boom luffing cylinder with a higher pressure. Instead, it will pass through the second oil port of the first solenoid valve connected to the first oil port of the main oil circuit and the first oil port of the first solenoid valve connected to the oil tank, and then enter the oil tank with a lower pressure. Since the hydraulic oil no longer enters the rod chamber of the boom luffing cylinder, the boom luffing cylinder can no longer retract and can only extend, that is, the boom can no longer luff downward but can only luff upward, thus preventing the aerial work vehicle from tipping over.

[0010] During the boom's lengthening or shortening, the second solenoid valve is normally closed. When hydraulic oil enters the rodless chamber of the boom's telescopic cylinder from the second port of the main oil circuit, the cylinder's piston extends, extending the boom. As the boom length increases, the distance between the boom's center of gravity and the aerial work vehicle's center of gravity increases, making the aerial work vehicle more susceptible to tipping. When the boom reaches its limit, the second solenoid valve is switched to an open state. At this point, hydraulic oil from the second port of the main oil circuit no longer enters the rodless chamber of the boom's telescopic cylinder, which has higher pressure. Instead, it flows through the second port of the second solenoid valve, which is connected to the second port of the main oil circuit, and the first port of the second solenoid valve, which is connected to the tank, into the lower-pressure tank. Since hydraulic oil no longer enters the rodless chamber of the boom's telescopic cylinder, the cylinder can no longer extend and can only retract. This means the boom can no longer lengthen but can only shorten, preventing the aerial work vehicle from tipping over.

[0011] During the counterclockwise or clockwise rotation of the turntable, the third solenoid valve is normally open. When hydraulic oil enters the turntable drive motor from the third or fourth port of the main oil circuit through the third solenoid valve, the turntable drive motor can drive the turntable to rotate counterclockwise or clockwise, thereby rotating the boom counterclockwise or clockwise relative to the vertical plane. As the turntable drives the boom to rotate so that the distance between the boom's center of gravity and the aerial work vehicle's left-right symmetry axis increases, the aerial work vehicle becomes more likely to tip over. When the turntable's rotation angle reaches the limit, the third solenoid valve is switched to the closed state. At this point, hydraulic oil from the third or fourth port of the main oil circuit no longer enters the turntable drive motor, causing the turntable drive motor to stop operating. This means that the turntable can no longer rotate, preventing the aerial work vehicle from tipping over.

[0012] To sum up, the above-mentioned boom hydraulic control system can control the boom lowering range, extension length and rotation angle by turning on and off the first solenoid valve, the second solenoid valve and the third solenoid valve, without adding other components outside the boom hydraulic control system, thereby saving costs. In addition, the above-mentioned boom hydraulic control system has a simple structure and can directly manually control the turning on and off of the first solenoid valve, the second solenoid valve and the third solenoid valve.

[0013] According to some embodiments of the present invention, the boom hydraulic control system also includes a first pipeline, one end of the first pipeline is used to communicate with the first oil port of the main oil circuit, the other end of the first pipeline is connected to the rod chamber of the boom boom cylinder, and the second oil port of the first solenoid valve is connected to the rod chamber of the boom boom cylinder and the first oil port of the main oil circuit through the first pipeline.

[0014] According to some embodiments of the present invention, the boom hydraulic control system also includes a second pipeline, one end of the second pipeline is used to connect with the second oil port of the main oil circuit, the other end of the second pipeline is connected with the rodless chamber of the boom telescopic cylinder, and the second oil port of the second solenoid valve is connected with the rodless chamber of the boom telescopic cylinder and the second oil port of the main oil circuit through the second pipeline.

[0015] According to some embodiments of the present invention, the boom hydraulic control system further includes a third pipeline and a fourth pipeline, one end of the third pipeline is used to communicate with the third oil port of the main oil circuit, and the other end of the third pipeline is communicated with the first oil port of the turntable drive motor; one end of the fourth pipeline is communicated with the fourth oil port of the main oil circuit, and the other end of the fourth pipeline is communicated with the second oil port of the turntable drive motor;

[0016] Wherein, the third solenoid valve is arranged on the third pipeline or the fourth pipeline.

[0017] According to some embodiments of the present invention, the main oil circuit includes a first relief valve, a first oil port of the first relief valve is connected to a third oil port of the main oil circuit, and a second oil port of the first relief valve is connected to an oil tank of the main oil circuit;

[0018] The main oil circuit includes a second overflow valve, a first oil port of the second overflow valve is communicated with a fourth oil port of the main oil circuit, and a second oil port of the second overflow valve is communicated with an oil tank of the main oil circuit.

[0019] According to the control method of the boom hydraulic control system of the second embodiment of the present invention, the method includes: judging whether the angle of the boom relative to the horizontal plane reaches the limit angle; when the angle of the boom relative to the horizontal plane reaches the limit angle, controlling the first solenoid valve to be energized so that the first oil port of the first solenoid valve is connected to the second oil port of the first solenoid valve; or judging whether the length of the boom reaches the limit length; when the length of the boom reaches the limit length, controlling the second solenoid valve to be energized so that the first oil port of the second solenoid valve is connected to the second oil port of the second solenoid valve; or judging whether the rotation angle of the turntable reaches the limit angle; when the rotation angle of the turntable reaches the limit angle, controlling the third solenoid valve to be energized so that the first oil port of the third solenoid valve is disconnected from the second oil port of the third solenoid valve.

[0020] The control method of the boom hydraulic control system according to the embodiment of the present invention has at least the following beneficial effects:

[0021] In the control method of the above-mentioned boom hydraulic control system, it is determined whether the angle of the boom relative to the horizontal plane has reached a limit angle. If the angle of the boom relative to the horizontal plane has reached the limit angle, that is, when the angle between the boom and the horizontal plane has reached the critical minimum angle for the aerial work vehicle to tip over, the first solenoid valve is controlled to be energized so that the first oil port of the first solenoid valve is connected to the second oil port of the first solenoid valve, causing the first solenoid valve to switch to an open state. At this time, the hydraulic oil in the first oil port of the main oil circuit will no longer enter the rod chamber of the boom boom cylinder with higher pressure. Instead, it will pass through the second oil port of the first solenoid valve connected to the first oil port of the main oil circuit and the first oil port of the first solenoid valve connected to the oil tank, and then enter the oil tank with lower pressure. Since the hydraulic oil no longer enters the rod chamber of the boom boom cylinder, the boom boom cylinder can no longer retract and can only extend. That is, the boom can no longer be adjusted downward, but can only be adjusted upward, thereby preventing the aerial work vehicle from tipping over.

[0022] Determine whether the length of the boom has reached the limit length. When the length of the boom has reached the limit length, that is, when the length of the boom has reached the critical maximum length for the aerial work vehicle to tip over, control the second solenoid valve to be energized so that the first oil port of the second solenoid valve is connected to the second oil port of the second solenoid valve, so that the second solenoid valve is switched to the open state. At this time, the hydraulic oil in the second oil port of the main oil circuit will no longer enter the rodless cavity of the boom telescopic cylinder with higher pressure, but will pass through the second oil port of the second solenoid valve connected to the second oil port of the main oil circuit and the first oil port of the second solenoid valve connected to the oil tank in sequence to enter the oil tank with lower pressure. Since the hydraulic oil no longer enters the rodless cavity of the boom telescopic cylinder, the boom telescopic cylinder can no longer be extended and can only be retracted, that is, the boom can no longer be lengthened and can only be shortened, thereby preventing the aerial work vehicle from tipping over.

[0023] The system determines whether the turntable's rotation angle has reached the limit angle. If the turntable's rotation angle reaches the limit angle, that is, if the turntable's rotation angle reaches the critical maximum angle for the aerial work vehicle to tip over, the third solenoid valve is energized to disconnect the first oil port of the third solenoid valve from the second oil port of the third solenoid valve, causing the third solenoid valve to switch to a closed state. At this time, hydraulic oil from the third oil port of the main oil circuit or the fourth oil port of the main oil circuit will no longer enter the turntable drive motor, so the turntable drive motor will stop running, that is, the turntable can no longer rotate, thereby preventing the aerial work vehicle from tipping over.

[0024] To sum up, the control method of the above-mentioned boom hydraulic control system can directly control the on and off of the first solenoid valve, the second solenoid valve and the third solenoid valve by judging the angle of the boom relative to the horizontal plane, the length of the boom and the rotation angle of the turntable, thereby realizing the control of the boom's lowering amplitude, extension length and rotation angle. It has a simple structure and is easy to operate.

[0025] According to some embodiments of the present invention, determining whether the angle of the boom relative to the horizontal plane reaches a limit angle includes: determining whether the angle of the boom relative to the horizontal plane reaches a first preset percentage of the limit angle;

[0026] When the angle of the boom relative to the horizontal plane reaches a limit angle, controlling the first solenoid valve to be energized so that the first oil port of the first solenoid valve is connected to the second oil port of the first solenoid valve includes:

[0027] When the angle of the boom relative to the horizontal plane reaches a first preset percentage of a limit angle, the first solenoid valve is controlled to be energized so that the passage between the first oil port of the first solenoid valve and the second oil port of the first solenoid valve is opened to a first preset opening, and the speed of the boom moving toward the horizontal plane is reduced according to the first preset ratio to a second preset percentage of the first preset speed;

[0028] When the speed of the boom changing toward the horizontal plane is reduced to a second preset percentage of the first preset speed according to a first preset ratio, the angle of the boom relative to the horizontal plane reaches the limit angle, and the channel between the first oil port of the first solenoid valve and the second oil port of the first solenoid valve is controlled to be fully opened.

[0029] According to some embodiments of the present invention, determining whether the length of the boom reaches a limited length includes: determining whether the length of the boom reaches a third preset percentage of the limited length;

[0030] When the length of the boom reaches a limit length, controlling the second solenoid valve to be energized so that the first oil port of the second solenoid valve is connected to the second oil port of the second solenoid valve includes:

[0031] When the length of the boom reaches a third preset percentage of the limit length, the second solenoid valve is controlled to be energized so that the passage between the first oil port of the second solenoid valve and the second oil port of the second solenoid valve is opened to a second preset opening, and the speed of change of the boom length is reduced to a third preset percentage of the second preset speed according to the second preset ratio;

[0032] When the speed of the arm's length change is reduced to a fourth preset percentage of the second preset speed according to the second preset ratio, the length of the arm reaches the limit length, and the channel between the first oil port of the second solenoid valve and the second oil port of the second solenoid valve is controlled to be fully opened.

[0033] According to some embodiments of the present invention, the determining whether the rotation angle of the turntable reaches the limit angle includes: determining whether the rotation angle of the turntable reaches a fifth preset percentage of the limit angle;

[0034] When the rotation angle of the turntable reaches a limited angle, controlling the third solenoid valve to be energized so as to disconnect the first oil port of the third solenoid valve from the second oil port of the third solenoid valve comprises:

[0035] When the rotation angle of the turntable reaches the fifth preset percentage of the limit angle, the third solenoid valve is controlled to be energized so that the channel between the first oil port of the third solenoid valve and the second oil port of the third solenoid valve is closed to the third preset opening, and the rotation speed of the turntable is reduced to the sixth preset percentage of the third preset speed according to the third preset ratio; and when the rotation speed of the turntable is reduced to the sixth preset percentage of the third preset speed according to the third preset ratio, the rotation angle of the turntable reaches the limit angle, and the channel between the first oil port of the third solenoid valve and the second oil port of the third solenoid valve is controlled to be completely closed.

[0036] An aerial work vehicle according to an embodiment of the third aspect of the present invention includes: the boom hydraulic control system as described above; or a control method using the boom hydraulic control system as described above.

[0037] In the above-mentioned aerial work vehicle, the above-mentioned boom hydraulic control system can control the boom's descent range, extension length, and rotation angle by switching the first solenoid valve, the second solenoid valve, and the third solenoid valve on and off, so that the above-mentioned aerial work vehicle will not tip over during operation, thereby providing the above-mentioned aerial work vehicle with good stability during operation. Furthermore, the control method of the above-mentioned boom hydraulic control system can directly control the switching of the first solenoid valve, the second solenoid valve, and the third solenoid valve by judging the boom's amplitude angle, the boom's length, and the boom's rotation angle, so that the above-mentioned boom hydraulic control system has the advantage of being easy to operate when controlling the boom's descent range, extension length, and rotation angle, thereby allowing the above-mentioned aerial work vehicle to more conveniently perform anti-tipping operations. Therefore, an aerial work vehicle having the above-mentioned boom hydraulic control system or applying the above-mentioned boom hydraulic control system control method has good stability during operation and can more conveniently perform anti-tipping operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0039] Figure 1 A schematic diagram of the structure of the boom hydraulic control system according to an embodiment of the present invention Figure 1 ;

[0040] Figure 2 A schematic diagram of the structure of the boom hydraulic control system according to an embodiment of the present invention Figure 2 .

[0041] Figure Number:

[0042] 100, main oil circuit; 110, first relief valve; 120, second relief valve;

[0043] 200, boom luffing cylinder; 210, first pipeline;

[0044] 300, boom telescopic cylinder; 310, second pipeline;

[0045] 400, first solenoid valve;

[0046] 500, fuel tank;

[0047] 600, second solenoid valve;

[0048] 700, turntable drive motor; 710, third pipeline; 720, fourth pipeline;

[0049] 800, the third solenoid valve. DETAILED DESCRIPTION

[0050] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0051] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0052] In the description of the present invention, "a plurality" refers to more than two. The use of "first" or "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of the indicated technical features, or implicitly indicating the order of the indicated technical features.

[0053] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0054] Reference Figure 1 As shown, a boom hydraulic control system according to an embodiment of the present invention includes: a main oil circuit 100, a boom luffing cylinder 200, a boom telescopic cylinder 300, a first solenoid valve 400, a second solenoid valve 600, a turntable drive motor 700 and a third solenoid valve 800.

[0055] Specifically, the boom luffing cylinder 200 is used to adjust the angle of the boom relative to the horizontal plane, and the rod chamber of the boom luffing cylinder 200 is connected to the first oil port a of the main oil circuit 100; the boom telescopic cylinder 300 is used to adjust the length of the boom, and the rodless chamber of the boom telescopic cylinder 300 is connected to the second oil port b of the main oil circuit 100; the first oil port e of the first solenoid valve 400 is used to communicate with the oil tank 500, and the rod chamber of the boom luffing cylinder 200 and the first oil port a of the main oil circuit 100 are both connected to the second oil port f of the first solenoid valve 400; the first oil port g of the second solenoid valve 600 is used to communicate with the oil tank 500. The rodless chamber of the boom telescopic cylinder 300 and the second oil port b of the main oil circuit 100 are connected to the second oil port h of the second solenoid valve 600; the turntable drive motor 700 is used to adjust the rotation angle of the turntable; the first oil port i of the third solenoid valve 800 is connected to the third oil port c of the main oil circuit 100, and the second oil port j of the third solenoid valve 800 is connected to the first oil port k of the turntable drive motor 700; or the first oil port i of the third solenoid valve 800 is connected to the fourth oil port d of the main oil circuit 100, and the second oil port j of the third solenoid valve 800 is connected to the second oil port m of the turntable drive motor 700.

[0056] More specifically, in one embodiment, the first solenoid valve 400, the second solenoid valve 600 and the third solenoid valve 800 can all be solenoid reversing valves. In addition, in other embodiments, the first solenoid valve 400, the second solenoid valve 600 and the third solenoid valve 800 can all be solenoid proportional valves.

[0057] In the above-mentioned boom hydraulic control system, the boom luffing cylinder 200 is used to adjust the angle of the boom relative to the horizontal plane. When the boom luffing cylinder 200 is extended, the boom can be luffed upward, and when the boom luffing cylinder 200 is retracted, the boom can be luffed downward; the boom telescopic cylinder 300 is used to adjust the length of the boom. When the boom telescopic cylinder 300 is extended, the length of the boom can be lengthened, and when the boom telescopic cylinder 300 is retracted, the length of the boom can be shortened; the turntable drive motor 700 is used to adjust the rotation angle of the turntable. The turntable drive motor 700 can drive the turntable to rotate counterclockwise or clockwise, so that the turntable can drive the turntable to rotate counterclockwise or clockwise.

[0058] During the boom's upward or downward luffing, the first solenoid valve 400 is normally closed. When hydraulic oil enters the rod chamber of the boom-luffing cylinder 200 from the first port a of the main oil circuit 100, the piston of the boom-luffing cylinder 200 contracts, allowing the boom to luff downward, decreasing the angle between the boom and the horizontal plane. As the angle between the boom and the horizontal plane decreases, the distance between the boom's center of gravity and the aerial work vehicle's center of gravity increases, making the aerial work vehicle more susceptible to tipping. When the boom-to-horizontal angle reaches a limit, the first solenoid valve 400 is switched to an open state. At this point, hydraulic oil from the first port a of the main oil circuit 100 no longer enters the rod chamber of the boom-luffing cylinder 200, which has a higher pressure. Instead, it flows sequentially through the second port f of the first solenoid valve 400, which is connected to the first port a of the main oil circuit 100, and the first port e of the first solenoid valve 400, which is connected to the oil tank 500, into the lower-pressure oil tank 500. Since the hydraulic oil no longer enters the rod chamber of the boom luffing cylinder 200, the boom luffing cylinder 200 can no longer retract and can only extend, that is, the boom can no longer luff downward but can only luff upward, thereby preventing the aerial work vehicle from tipping over.

[0059] During the boom lengthening or shortening process, the second solenoid valve 600 is normally closed. When hydraulic oil enters the rodless chamber of the boom extension cylinder 300 from the second oil port b of the main oil circuit 100, the piston of the boom extension cylinder 300 extends, extending the boom. As the boom length increases, the distance between the boom's center of gravity and the aerial work vehicle's center of gravity increases, making the aerial work vehicle more likely to tip over. When the boom length reaches the limit, the second solenoid valve 600 is switched to the open state. At this time, the hydraulic oil in the second oil port b of the main oil circuit 100 no longer enters the rodless chamber of the boom extension cylinder 300, which has a higher pressure. Instead, it passes through the second oil port h of the second solenoid valve 600, which is connected to the second oil port b of the main oil circuit 100, and the first oil port g of the second solenoid valve 600, which is connected to the oil tank 500, and then enters the oil tank 500, which has a lower pressure. Since the hydraulic oil no longer enters the rodless cavity of the boom telescopic cylinder 300, the boom telescopic cylinder 300 can no longer extend but can only retract, that is, the boom can no longer lengthen but can only shorten, thereby preventing the aerial work vehicle from tipping over.

[0060] During the counterclockwise or clockwise rotation of the turntable, the third solenoid valve 800 is normally open. When hydraulic oil enters the turntable drive motor 700 from the third oil port c of the main oil circuit 100 or from the fourth oil port d of the main oil circuit 100 through the third solenoid valve 800, the turntable drive motor 700 can drive the turntable to rotate counterclockwise or clockwise, thereby causing the boom to rotate counterclockwise or clockwise relative to the vertical plane. When the turntable drives the boom to rotate so that the distance between the boom's center of gravity and the left-right symmetry axis of the aerial work vehicle increases, the aerial work vehicle is more likely to tip over. When the turntable's rotation angle reaches the limit angle, the third solenoid valve 800 can be switched to the closed state. At this time, the hydraulic oil from the third oil port c of the main oil circuit 100 or the fourth oil port d of the main oil circuit 100 will no longer enter the turntable drive motor 700, so the turntable drive motor 700 will stop running, that is, the turntable can no longer rotate, so that the aerial work vehicle will not tip over.

[0061] To sum up, the above-mentioned boom hydraulic control system can control the boom's lowering range, extension length and rotation angle by turning on and off the first solenoid valve 400, the second solenoid valve 600 and the third solenoid valve 800, without adding other components outside the boom hydraulic control system, thereby saving costs. In addition, the above-mentioned boom hydraulic control system has a simple structure and can directly manually control the on and off of the first solenoid valve 400, the second solenoid valve 600 and the third solenoid valve 800.

[0062] Reference Figure 1 As shown, it can be understood that the boom hydraulic control system also includes a first pipeline 210, one end of the first pipeline 210 is used to communicate with the first oil port a of the main oil circuit 100, and the other end of the first pipeline 210 is connected to the rod chamber of the boom luffing cylinder 200, and the second oil port f of the first solenoid valve 400 is connected to the rod chamber of the boom luffing cylinder 200 and the first oil port a of the main oil circuit 100 through the first pipeline 210.

[0063] In this way, when hydraulic oil enters the rod chamber of the boom-booming cylinder 200 from the first oil port a of the main oil circuit 100 through the first pipeline 210, the piston of the boom-booming cylinder 200 can be retracted, allowing the boom to be luffed downward, making the angle between the boom and the horizontal plane smaller and smaller. When the angle between the boom and the horizontal plane reaches the limit angle, the first solenoid valve 400 can be switched to the open state. At this time, the hydraulic oil in the first oil port a of the main oil circuit 100 will no longer enter the rod chamber of the boom-booming cylinder 200 with higher pressure through the first pipeline 210. Instead, it will pass through the first pipeline 210, sequentially through the second oil port f of the first solenoid valve 400 connected to the first oil port a of the main oil circuit 100, and the first oil port e of the first solenoid valve 400 connected to the oil tank 500, and enter the oil tank 500 with lower pressure. Since the hydraulic oil no longer enters the rod chamber of the boom luffing cylinder 200 through the first pipeline 210, the boom luffing cylinder 200 can no longer retract and can only extend, that is, the boom can no longer luff downward but can only luff upward, thereby preventing the aerial work vehicle from tipping over.

[0064] Reference Figure 1 As shown, it can be understood that the boom hydraulic control system also includes a second pipeline 310, one end of the second pipeline 310 is used to communicate with the second oil port b of the main oil circuit 100, and the other end of the second pipeline 310 is connected to the rodless cavity of the boom telescopic cylinder 300, and the second oil port h of the second solenoid valve 600 is connected to the rodless cavity of the boom telescopic cylinder 300 and the second oil port b of the main oil circuit 100 through the second pipeline 310.

[0065] In this way, when hydraulic oil enters the rodless cavity of the boom extension cylinder 300 from the second oil port b of the main oil circuit 100 through the second pipeline 310, the piston of the boom extension cylinder 300 can be extended, thereby increasing the length of the boom. When the boom reaches the limit length, the second solenoid valve 600 can be switched to the open state. At this time, the hydraulic oil in the second oil port b of the main oil circuit 100 will no longer enter the rodless cavity of the boom extension cylinder 300 with higher pressure through the second pipeline 310. Instead, it will pass through the second pipeline 310, sequentially through the second oil port h of the second solenoid valve 600 connected to the second oil port b of the main oil circuit 100, and the first oil port g of the second solenoid valve 600 connected to the oil tank 500, and then enter the oil tank 500 with lower pressure. Since the hydraulic oil no longer enters the rodless cavity of the boom telescopic cylinder 300 through the second pipeline 310, the boom telescopic cylinder 300 can no longer extend but can only retract, that is, the boom can no longer lengthen but can only shorten, so that the aerial work vehicle will not tip over.

[0066] Reference Figure 1 as well as Figure 2As shown, it can be understood that the boom hydraulic control system also includes a third pipeline 710 and a fourth pipeline 720, one end of the third pipeline 710 is used to communicate with the third oil port c of the main oil circuit 100, and the other end of the third pipeline 710 is connected to the first oil port k of the turntable drive motor 700, one end of the fourth pipeline 720 is connected to the fourth oil port d of the main oil circuit 100, and the other end of the fourth pipeline 720 is connected to the second oil port m of the turntable drive motor 700; wherein, the third solenoid valve 800 is arranged on the third pipeline 710 or the fourth pipeline 720.

[0067] Specifically, in one embodiment, when the hydraulic oil enters the first oil port k of the turntable drive motor 700 from the third oil port c of the main oil circuit 100 through the third pipeline 710, and the hydraulic oil in the second oil port m of the turntable drive motor 700 enters the fourth oil port d of the main oil circuit 100 through the fourth pipeline 720, the turntable drive motor 700 can drive the turntable to rotate counterclockwise; when the hydraulic oil enters the second oil port m of the turntable drive motor 700 from the fourth oil port d of the main oil circuit 100 through the fourth pipeline 720, and the hydraulic oil in the first oil port k of the turntable drive motor 700 enters the third oil port c of the main oil circuit 100 through the third pipeline 710, the turntable drive motor 700 can drive the turntable to rotate clockwise. In addition, in other embodiments, when the hydraulic oil enters the first oil port k of the turntable drive motor 700 from the third oil port c of the main oil circuit 100 through the third pipeline 710, and the hydraulic oil in the second oil port m of the turntable drive motor 700 enters the fourth oil port d of the main oil circuit 100 through the fourth pipeline 720, the turntable drive motor 700 can drive the turntable to rotate clockwise; when the hydraulic oil enters the second oil port m of the turntable drive motor 700 from the fourth oil port d of the main oil circuit 100 through the fourth pipeline 720, and the hydraulic oil in the first oil port k of the turntable drive motor 700 enters the third oil port c of the main oil circuit 100 through the third pipeline 710, the turntable drive motor 700 can drive the turntable to rotate counterclockwise.

[0068] So, refer to Figure 1As shown, when the third solenoid valve 800 is installed on the third pipeline 710, hydraulic oil can flow through the third pipeline 710, sequentially through the third oil port c of the main oil circuit 100, the first oil port i of the third solenoid valve 800, and the second oil port j of the third solenoid valve 800, into the first oil port k of the turntable drive motor 700. The hydraulic oil in the second oil port m of the turntable drive motor 700 can flow through the fourth pipeline 720 into the fourth oil port d of the main oil circuit 100. At this time, the turntable drive motor 700 can drive the turntable to rotate counterclockwise or clockwise, thereby rotating the boom counterclockwise or clockwise relative to the vertical plane. When the rotation angle of the turntable reaches the limit angle, the third solenoid valve 800 can be switched to the closed state. At this time, the hydraulic oil in the third oil port c of the main oil circuit 100 will no longer enter the first oil port k of the turntable drive motor 700 through the third pipeline 710, so the turntable drive motor 700 will stop running, that is, the turntable can no longer rotate, so that the aerial work vehicle will not tip over.

[0069] Reference Figure 2 As shown, when the third solenoid valve 800 is installed on the fourth pipeline 720, hydraulic oil can flow through the fourth pipeline 720, sequentially through the fourth oil port d of the main oil circuit 100, the first oil port i of the third solenoid valve 800, and the second oil port j of the third solenoid valve 800, and then enter the second oil port m of the turntable drive motor 700. The hydraulic oil in the first oil port k of the turntable drive motor 700 can flow through the third pipeline 710 and enter the third oil port c of the main oil circuit 100. At this time, the turntable drive motor 700 can drive the turntable to rotate counterclockwise or clockwise, so that the boom can rotate counterclockwise or clockwise relative to the vertical plane. When the rotation angle of the turntable reaches the limit angle, the third solenoid valve 800 can be switched to the closed state. At this time, the hydraulic oil in the fourth oil port d of the main oil circuit 100 will no longer enter the second oil port m of the turntable drive motor 700 through the fourth pipeline 720, so the turntable drive motor 700 will stop running, that is, the turntable can no longer rotate, so that the aerial work vehicle will not tip over.

[0070] Reference Figure 1 as well as Figure 2 As shown, it can be understood that the main oil circuit 100 includes a first overflow valve 110, the first oil port n of the first overflow valve 110 is connected to the third oil port c of the main oil circuit 100, and the second oil port p of the first overflow valve 110 is connected to the oil tank 500 of the main oil circuit 100; the main oil circuit 100 includes a second overflow valve 120, the first oil port q of the second overflow valve 120 is connected to the fourth oil port d of the main oil circuit 100, and the second oil port r of the second overflow valve 120 is connected to the oil tank 500 of the main oil circuit 100.

[0071] So, refer to Figure 1 As shown, since the first oil port n of the first relief valve 110 is connected to the third oil port c of the main oil circuit 100, and the second oil port p of the first relief valve 110 is connected to the oil tank 500 of the main oil circuit 100, when the third solenoid valve 800 is set on the third pipeline 710, the third solenoid valve 800 is switched to the closed state. At this time, the hydraulic oil between the third oil port c of the main oil circuit 100 and the first oil port i of the third solenoid valve 800 will flow to the first relief valve 110 with lower pressure, and flow into the oil tank 500 of the main oil circuit 100 through the first relief valve 110, thereby playing a certain pressure relief role for the pipeline between the third oil port c of the main oil circuit 100 and the first oil port i of the third solenoid valve 800.

[0072] Reference Figure 2 As shown, since the first oil port q of the second overflow valve 120 is connected to the fourth oil port d of the main oil circuit 100, and the second oil port r of the second overflow valve 120 is connected to the oil tank 500 of the main oil circuit 100, when the third solenoid valve 800 is set on the fourth pipeline 720, the third solenoid valve 800 is switched to the closed state. At this time, the hydraulic oil between the fourth oil port d of the main oil circuit 100 and the first oil port i of the third solenoid valve 800 will flow to the second overflow valve 120 with lower pressure, and flow into the oil tank 500 of the main oil circuit 100 through the second overflow valve 120, thereby playing a certain pressure relief role for the pipeline between the fourth oil port d of the main oil circuit 100 and the first oil port i of the third solenoid valve 800.

[0073] A control method for a boom hydraulic control system according to an embodiment of the present invention includes:

[0074] Determine whether the angle of the boom relative to the horizontal plane reaches a limit angle; if the angle of the boom relative to the horizontal plane reaches the limit angle, control the first solenoid valve 400 to be energized so that the first oil port e of the first solenoid valve 400 is connected to the second oil port f of the first solenoid valve 400;

[0075] or determining whether the length of the boom reaches the limit length; if the length of the boom reaches the limit length, controlling the second solenoid valve 600 to be energized so that the first oil port g of the second solenoid valve 600 is connected to the second oil port h of the second solenoid valve 600;

[0076] Or determine whether the rotation angle of the turntable reaches the limit angle; when the rotation angle of the turntable reaches the limit angle, control the third solenoid valve 800 to be energized so that the first oil port i of the third solenoid valve 800 is disconnected from the second oil port j of the third solenoid valve 800.

[0077] It should be noted that the above-mentioned boom hydraulic control system also includes an angle sensor, a length sensor, a rotary encoder and a controller, wherein the angle sensor is used to detect the angle of the boom's upward or downward amplitude change, and transmit the boom's amplitude change angle signal to the controller, the length sensor is used to detect the length of the boom's extension or shortening, and transmit the boom's length signal to the controller, the rotary encoder is used to detect the rotation angle of the turntable, and transmit the turntable's rotation angle signal to the controller, the controller is used to determine whether the boom's amplitude change angle reaches the limit angle, and also to determine whether the boom's length reaches the limit length, and to determine whether the turntable's rotation angle reaches the limit angle.

[0078] In the above-mentioned control method for the boom hydraulic control system, a determination is made as to whether the boom angle relative to the horizontal plane has reached a limit angle. If the boom angle relative to the horizontal plane has reached the limit angle, that is, if the angle between the boom and the horizontal plane has reached the critical minimum angle for the aerial work vehicle to tip over, the first solenoid valve 400 is energized to connect the first oil port e of the first solenoid valve 400 with the second oil port f of the first solenoid valve 400, thereby switching the first solenoid valve 400 to an open state. At this point, the hydraulic oil in the first oil port a of the main oil circuit 100 no longer enters the rod chamber of the boom luffing cylinder 200, which has a higher pressure. Instead, the hydraulic oil passes through the second oil port f of the first solenoid valve 400, which is connected to the first oil port a of the main oil circuit 100, and the first oil port e of the first solenoid valve 400, which is connected to the oil tank 500, and then enters the oil tank 500, which has a lower pressure. Since the hydraulic oil no longer enters the rod chamber of the boom luffing cylinder 200, the boom luffing cylinder 200 can no longer retract and can only extend, that is, the boom can no longer luff downward but can only luff upward, thereby preventing the aerial work vehicle from tipping over.

[0079] The system determines whether the boom length has reached the limit. If the boom length has reached the limit, i.e., the maximum critical length for the aerial work vehicle to tip over, the second solenoid valve 600 is energized, connecting the first port g of the second solenoid valve 600 with the second port h of the second solenoid valve 600, thereby switching the second solenoid valve 600 to the open state. At this point, hydraulic oil from the second port b of the main oil circuit 100 no longer enters the rodless chamber of the boom extension cylinder 300, which has a higher pressure. Instead, it passes through the second port h of the second solenoid valve 600, which is connected to the second port b of the main oil circuit 100, and the first port g of the second solenoid valve 600, which is connected to the fuel tank 500, and enters the fuel tank 500, which has a lower pressure. Since hydraulic oil no longer enters the rodless chamber of the boom extension cylinder 300, the boom extension cylinder 300 can no longer extend and can only retract. This means that the boom can no longer lengthen and can only shorten, thus preventing the aerial work vehicle from tipping over.

[0080] The system determines whether the turntable's rotation angle has reached the limit angle. If the turntable's rotation angle reaches the limit angle, that is, if the turntable's rotation angle reaches the critical maximum angle for the aerial work vehicle to tip over, the third solenoid valve 800 is energized to disconnect the first oil port i of the third solenoid valve 800 from the second oil port j of the third solenoid valve 800, causing the third solenoid valve 800 to switch to the closed state. At this time, hydraulic oil from the third oil port c of the main oil circuit 100 or the fourth oil port d of the main oil circuit 100 will no longer enter the turntable drive motor 700, thereby stopping the turntable drive motor 700. In other words, the turntable can no longer rotate, thereby preventing the aerial work vehicle from tipping over.

[0081] To sum up, the control method of the above-mentioned boom hydraulic control system can directly control the on and off of the first solenoid valve 400, the second solenoid valve 600 and the third solenoid valve 800 by judging the angle of the boom relative to the horizontal plane, the length of the boom and the rotation angle of the turntable, thereby realizing the control of the boom's lowering amplitude, extension length and rotation angle. It has a simple structure and is easy to operate.

[0082] It can be understood that determining whether the angle of the boom relative to the horizontal plane reaches the limit angle includes: determining whether the angle of the boom relative to the horizontal plane reaches a first preset percentage of the limit angle; when the angle of the boom relative to the horizontal plane reaches the limit angle, controlling the first solenoid valve 400 to be energized so that the first oil port e of the first solenoid valve 400 is connected to the second oil port f of the first solenoid valve 400 includes: when the angle of the boom relative to the horizontal plane reaches a first preset percentage of the limit angle, controlling the first solenoid valve 400 to be energized so that the channel between the first oil port e of the first solenoid valve 400 and the second oil port f of the first solenoid valve 400 is opened to a first preset opening, and the speed of the downward amplitude change of the boom is reduced to a second preset percentage of the first preset speed according to a first preset ratio; when the speed of the downward amplitude change of the boom is reduced to the second preset percentage of the first preset speed according to the first preset ratio, the angle of the boom relative to the horizontal plane reaches the limit angle, and the channel between the first oil port e of the first solenoid valve 400 and the second oil port f of the first solenoid valve 400 is controlled to be completely open.

[0083] Specifically, the first solenoid valve 400 is a first solenoid proportional valve, with a first preset percentage between 85% and 95%, and a second preset percentage between 25% and 35%. The first preset opening, first preset ratio, and first preset speed can be determined based on various system components, including the model and size of the boom, the model and size of the boom luffing cylinder 200, the diameter of the hydraulic pipeline, the power of the hydraulic pump, and actual operating conditions.

[0084] In this way, when the boom's angle relative to the horizontal plane reaches a first preset percentage of the limit angle, the first solenoid valve 400 is controlled to be energized to connect the first oil port e of the first solenoid valve 400 with the second oil port f of the first solenoid valve 400. This opens the passage between the first oil port e of the first solenoid valve 400 and the second oil port f of the first solenoid valve 400 to a first preset opening, thereby reducing the boom's downward amplitude change speed according to the first preset ratio to a second preset percentage of the first preset speed. This allows the first solenoid valve 400 to open slowly, allowing the boom to decelerate in advance and slowly stop at the second preset percentage of the first preset speed. Therefore, during the process of stopping the boom's amplitude change relative to the horizontal plane, the impact caused by the sudden cessation of amplitude change can be reduced, thereby ensuring the stability of the boom and the aerial work vehicle.

[0085] It can be understood that determining whether the length of the boom reaches the limit length includes: determining whether the length of the boom reaches the third preset percentage of the limit length; when the length of the boom reaches the limit length, controlling the second solenoid valve 600 to be energized so that the first oil port g of the second solenoid valve 600 is connected to the second oil port h of the second solenoid valve 600 includes: when the length of the boom reaches the third preset percentage of the limit length, controlling the second solenoid valve 600 to be energized so that the channel between the first oil port g of the second solenoid valve 600 and the second oil port h of the second solenoid valve 600 is opened to the second preset opening, and the speed of change of the boom length is reduced to the third preset percentage of the second preset speed according to the second preset ratio; when the speed of change of the boom length is reduced to the fourth preset percentage of the second preset speed according to the second preset ratio, the length of the boom reaches the limit length, and the channel between the first oil port g of the second solenoid valve 600 and the second oil port h of the second solenoid valve 600 is controlled to be completely open.

[0086] Specifically, the second solenoid valve 600 is a second solenoid proportional valve. The third preset percentage is between 85% and 95%, and the fourth preset percentage is between 25% and 35%. The second preset opening, second preset ratio, and second preset speed can be determined based on various system components, including the model and size of the boom, the model and size of the boom luffing cylinder 200, the diameter of the hydraulic pipeline, the power of the hydraulic pump, and actual operating conditions.

[0087] In this way, when the boom length reaches a third preset percentage of the limit length, the second solenoid valve 600 is energized to connect the first oil port g of the second solenoid valve 600 with the second oil port h of the second solenoid valve 600. This opens the passage between the first oil port g of the second solenoid valve 600 and the second oil port h of the second solenoid valve 600 to a second preset opening degree, thereby reducing the speed of change of the boom length according to the second preset ratio to a third preset percentage of the second preset speed. This allows the second solenoid valve 600 to open slowly, allowing the boom to decelerate in advance and slowly stop at a fourth preset percentage of the second preset speed. Therefore, during the process of stopping the boom extension, the impact caused by the sudden stop of the boom extension can be reduced, thereby ensuring the stability of the boom and the aerial work vehicle.

[0088] It can be understood that judging whether the rotation angle of the turntable reaches the limit angle includes: judging whether the rotation angle of the turntable reaches the fifth preset percentage of the limit angle; when the rotation angle of the turntable reaches the limit angle, controlling the third solenoid valve 800 to be energized so that the first oil port i of the third solenoid valve 800 and the second oil port j of the third solenoid valve 800 are disconnected includes: when the rotation angle of the turntable reaches the fifth preset percentage of the limit angle, controlling the third solenoid valve 800 to be energized so that the channel between the first oil port i of the third solenoid valve 800 and the second oil port j of the third solenoid valve 800 is closed to a third preset opening, and the rotation speed of the turntable is reduced to a sixth preset percentage of the third preset speed according to the third preset ratio; and when the rotation speed of the turntable is reduced to a sixth preset percentage of the third preset speed according to the third preset ratio, the rotation angle of the turntable reaches the limit angle, and the channel between the first oil port i of the third solenoid valve 800 and the second oil port j of the third solenoid valve 800 is controlled to be completely closed.

[0089] Specifically, the third solenoid valve 800 is a third solenoid proportional valve. The fifth preset percentage is between 85% and 95%, and the sixth preset percentage is between 25% and 35%. The third preset opening, third preset ratio, and third preset speed can be determined based on various system components, including the model and size of the boom, the model and size of the boom luffing cylinder 200, the diameter of the hydraulic pipeline, the power of the hydraulic pump, and actual operating conditions.

[0090] In this way, when the turntable's rotation angle reaches the fifth preset percentage of the limit angle, the third solenoid valve 800 is energized to close the passage between the first oil port i and the second oil port j of the third solenoid valve 800 to a third preset opening, and the turntable's rotation speed is reduced according to the third preset ratio to a sixth preset percentage of the third preset speed. This allows the third solenoid valve 800 to close slowly, allowing the boom to decelerate in advance and slowly stop at the sixth preset percentage of the third preset speed. Therefore, during the process of stopping the turntable's rotation, the impact caused by the boom's sudden stop can be reduced, thereby ensuring the stability of the boom and the aerial work vehicle.

[0091] An aerial work vehicle according to an embodiment of the present invention includes: the boom hydraulic control system as described above; or a control method using the boom hydraulic control system as described above.

[0092] In the above-mentioned aerial work vehicle, the boom hydraulic control system can control the boom's descent range, extension length, and rotation angle by switching the first solenoid valve 400, the second solenoid valve 600, and the third solenoid valve 800 on and off, so that the above-mentioned aerial work vehicle will not tip over during operation, thereby providing the above-mentioned aerial work vehicle with good stability during operation. Furthermore, the control method of the above-mentioned boom hydraulic control system can directly control the switching of the first solenoid valve 400, the second solenoid valve 600, and the third solenoid valve 800 by judging the boom's amplitude adjustment angle, the boom's length, and the rotation angle of the slewing platform. This makes the above-mentioned boom hydraulic control system easy to operate when controlling the boom's descent range, extension length, and rotation angle, thereby allowing the above-mentioned aerial work vehicle to more conveniently perform anti-tipping operations. Therefore, an aerial work vehicle equipped with the above-mentioned boom hydraulic control system or using the above-mentioned boom hydraulic control system control method has good stability during operation and can more conveniently perform anti-tipping operations.

[0093] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A control method for a boom hydraulic control system, characterized in that: Applied to the boom hydraulic control system, the boom hydraulic control system includes: Main oil line; A boom luffing cylinder, the boom luffing cylinder being used to adjust the angle of the boom relative to the horizontal plane, the rod chamber of the boom luffing cylinder being in communication with the first oil port of the main oil circuit; A boom telescopic oil cylinder, the boom telescopic oil cylinder is used to adjust the length of the boom, and the rodless chamber of the boom telescopic oil cylinder is connected to the second oil port of the main oil circuit; a first solenoid valve, wherein the first oil port of the first solenoid valve is connected to the oil tank, and the rod chamber of the boom luffing cylinder and the first oil port of the main oil circuit are both connected to the second oil port of the first solenoid valve; a second solenoid valve, wherein the first oil port of the second solenoid valve is used to communicate with the oil tank, and the rodless chamber of the boom telescopic oil cylinder and the second oil port of the main oil circuit are both connected to the second oil port of the second solenoid valve; a turntable drive motor, the turntable drive motor being used to adjust the rotation angle of the turntable; and a third solenoid valve, wherein the first oil port of the third solenoid valve is connected to the third oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the first oil port of the turntable drive motor; or the first oil port of the third solenoid valve is connected to the fourth oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the second oil port of the turntable drive motor; The control method of the boom hydraulic control system includes: determining whether the angle of the boom relative to the horizontal plane reaches a limit angle; if the angle of the boom relative to the horizontal plane reaches the limit angle, controlling the first solenoid valve to be energized so that the first oil port of the first solenoid valve is connected to the second oil port of the first solenoid valve; Wherein, the determining whether the angle of the boom relative to the horizontal plane reaches the limit angle comprises: determining whether the angle of the boom relative to the horizontal plane reaches a first preset percentage of the limit angle; When the angle of the boom relative to the horizontal plane reaches a limit angle, controlling the first solenoid valve to be energized so that the first oil port of the first solenoid valve is connected to the second oil port of the first solenoid valve includes: When the angle of the boom relative to the horizontal plane reaches a first preset percentage of a limit angle, the first solenoid valve is controlled to be energized so that the passage between the first oil port of the first solenoid valve and the second oil port of the first solenoid valve is opened to a first preset opening, and the speed of the boom moving toward the horizontal plane is reduced according to the first preset ratio to a second preset percentage of the first preset speed; When the speed of the boom changing toward the horizontal plane is reduced to a second preset percentage of the first preset speed according to a first preset ratio, the angle of the boom relative to the horizontal plane reaches the limit angle, and the channel between the first oil port of the first solenoid valve and the second oil port of the first solenoid valve is controlled to be fully opened.

2. The control method of the boom hydraulic control system according to claim 1, characterized in that: The boom hydraulic control system also includes a first pipeline, one end of the first pipeline is used to communicate with the first oil port of the main oil circuit, the other end of the first pipeline is connected to the rod chamber of the boom boom cylinder, and the second oil port of the first solenoid valve is connected to the rod chamber of the boom boom cylinder and the first oil port of the main oil circuit through the first pipeline.

3. The control method of the boom hydraulic control system according to claim 1, characterized in that: The boom hydraulic control system also includes a second pipeline, one end of the second pipeline is used to communicate with the second oil port of the main oil circuit, the other end of the second pipeline is connected to the rodless chamber of the boom telescopic cylinder, and the second oil port of the second solenoid valve is connected to the rodless chamber of the boom telescopic cylinder and the second oil port of the main oil circuit through the second pipeline.

4. The control method of the boom hydraulic control system according to claim 1, characterized in that: The boom hydraulic control system further includes a third pipeline and a fourth pipeline, one end of the third pipeline is used to communicate with the third oil port of the main oil circuit, and the other end of the third pipeline is communicated with the first oil port of the turntable drive motor; one end of the fourth pipeline is communicated with the fourth oil port of the main oil circuit, and the other end of the fourth pipeline is communicated with the second oil port of the turntable drive motor; Wherein, the third solenoid valve is arranged on the third pipeline or the fourth pipeline.

5. The control method of the boom hydraulic control system according to claim 4, characterized in that: The main oil circuit includes a first relief valve, a first oil port of the first relief valve is connected to a third oil port of the main oil circuit, and a second oil port of the first relief valve is connected to an oil tank of the main oil circuit; The main oil circuit includes a second overflow valve, a first oil port of the second overflow valve is communicated with a fourth oil port of the main oil circuit, and a second oil port of the second overflow valve is communicated with an oil tank of the main oil circuit.

6. A control method for a boom hydraulic control system, characterized in that: Applied to the boom hydraulic control system, the boom hydraulic control system includes: Main oil line; A boom luffing cylinder, the boom luffing cylinder being used to adjust the angle of the boom relative to the horizontal plane, the rod chamber of the boom luffing cylinder being in communication with the first oil port of the main oil circuit; A boom telescopic oil cylinder, the boom telescopic oil cylinder is used to adjust the length of the boom, and the rodless chamber of the boom telescopic oil cylinder is connected to the second oil port of the main oil circuit; a first solenoid valve, wherein the first oil port of the first solenoid valve is connected to the oil tank, and the rod chamber of the boom luffing cylinder and the first oil port of the main oil circuit are both connected to the second oil port of the first solenoid valve; a second solenoid valve, wherein the first oil port of the second solenoid valve is used to communicate with the oil tank, and the rodless chamber of the boom telescopic oil cylinder and the second oil port of the main oil circuit are both connected to the second oil port of the second solenoid valve; a turntable drive motor, the turntable drive motor being used to adjust the rotation angle of the turntable; and a third solenoid valve, wherein the first oil port of the third solenoid valve is connected to the third oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the first oil port of the turntable drive motor; or the first oil port of the third solenoid valve is connected to the fourth oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the second oil port of the turntable drive motor; The control method of the boom hydraulic control system includes: determining whether the length of the boom reaches a limit length; if the length of the boom reaches the limit length, controlling the second solenoid valve to be energized so that the first oil port of the second solenoid valve is connected to the second oil port of the second solenoid valve; Wherein, the determining whether the length of the boom reaches the limit length includes: determining whether the length of the boom reaches a third preset percentage of the limit length; When the length of the boom reaches a limit length, controlling the second solenoid valve to be energized so that the first oil port of the second solenoid valve is connected to the second oil port of the second solenoid valve includes: When the length of the boom reaches a third preset percentage of the limit length, the second solenoid valve is controlled to be energized so that the passage between the first oil port of the second solenoid valve and the second oil port of the second solenoid valve is opened to a second preset opening, and the speed of change of the boom length is reduced to a third preset percentage of the second preset speed according to the second preset ratio; When the speed of the arm's length change is reduced to a fourth preset percentage of the second preset speed according to the second preset ratio, the length of the arm reaches the limit length, and the channel between the first oil port of the second solenoid valve and the second oil port of the second solenoid valve is controlled to be fully opened.

7. The control method of the boom hydraulic control system according to claim 6, characterized in that: The boom hydraulic control system also includes a first pipeline, one end of the first pipeline is used to communicate with the first oil port of the main oil circuit, the other end of the first pipeline is connected to the rod chamber of the boom boom cylinder, and the second oil port of the first solenoid valve is connected to the rod chamber of the boom boom cylinder and the first oil port of the main oil circuit through the first pipeline.

8. The control method of the boom hydraulic control system according to claim 6, characterized in that: The boom hydraulic control system also includes a second pipeline, one end of the second pipeline is used to communicate with the second oil port of the main oil circuit, the other end of the second pipeline is connected to the rodless chamber of the boom telescopic cylinder, and the second oil port of the second solenoid valve is connected to the rodless chamber of the boom telescopic cylinder and the second oil port of the main oil circuit through the second pipeline.

9. The control method of the boom hydraulic control system according to claim 6, characterized in that: The boom hydraulic control system further includes a third pipeline and a fourth pipeline, one end of the third pipeline is used to communicate with the third oil port of the main oil circuit, and the other end of the third pipeline is communicated with the first oil port of the turntable drive motor; one end of the fourth pipeline is communicated with the fourth oil port of the main oil circuit, and the other end of the fourth pipeline is communicated with the second oil port of the turntable drive motor; Wherein, the third solenoid valve is arranged on the third pipeline or the fourth pipeline.

10. The control method of the boom hydraulic control system according to claim 9, characterized in that: The main oil circuit includes a first relief valve, a first oil port of the first relief valve is connected to a third oil port of the main oil circuit, and a second oil port of the first relief valve is connected to an oil tank of the main oil circuit; The main oil circuit includes a second overflow valve, a first oil port of the second overflow valve is communicated with a fourth oil port of the main oil circuit, and a second oil port of the second overflow valve is communicated with an oil tank of the main oil circuit.

11. A control method for a boom hydraulic control system, characterized in that: Applied to the boom hydraulic control system, the boom hydraulic control system includes: Main oil line; A boom luffing cylinder, the boom luffing cylinder being used to adjust the angle of the boom relative to the horizontal plane, the rod chamber of the boom luffing cylinder being in communication with the first oil port of the main oil circuit; A boom telescopic oil cylinder, the boom telescopic oil cylinder is used to adjust the length of the boom, and the rodless chamber of the boom telescopic oil cylinder is connected to the second oil port of the main oil circuit; a first solenoid valve, wherein the first oil port of the first solenoid valve is connected to the oil tank, and the rod chamber of the boom luffing cylinder and the first oil port of the main oil circuit are both connected to the second oil port of the first solenoid valve; a second solenoid valve, wherein the first oil port of the second solenoid valve is used to communicate with the oil tank, and the rodless chamber of the boom telescopic oil cylinder and the second oil port of the main oil circuit are both connected to the second oil port of the second solenoid valve; a turntable drive motor, the turntable drive motor being used to adjust the rotation angle of the turntable; and a third solenoid valve, wherein the first oil port of the third solenoid valve is connected to the third oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the first oil port of the turntable drive motor; or the first oil port of the third solenoid valve is connected to the fourth oil port of the main oil circuit, and the second oil port of the third solenoid valve is connected to the second oil port of the turntable drive motor; The control method of the boom hydraulic control system includes: Determine whether the rotation angle of the turntable reaches a limit angle; when the rotation angle of the turntable reaches the limit angle, control the third solenoid valve to be energized so that the first oil port of the third solenoid valve is disconnected from the second oil port of the third solenoid valve; Wherein, the determining whether the rotation angle of the turntable reaches the limit angle includes: determining whether the rotation angle of the turntable reaches a fifth preset percentage of the limit angle; When the rotation angle of the turntable reaches a limited angle, controlling the third solenoid valve to be energized so as to disconnect the first oil port of the third solenoid valve from the second oil port of the third solenoid valve comprises: When the rotation angle of the turntable reaches the fifth preset percentage of the limit angle, the third solenoid valve is controlled to be energized so that the channel between the first oil port of the third solenoid valve and the second oil port of the third solenoid valve is closed to the third preset opening, and the rotation speed of the turntable is reduced to the sixth preset percentage of the third preset speed according to the third preset ratio; and when the rotation speed of the turntable is reduced to the sixth preset percentage of the third preset speed according to the third preset ratio, the rotation angle of the turntable reaches the limit angle, and the channel between the first oil port of the third solenoid valve and the second oil port of the third solenoid valve is controlled to be completely closed.

12. The control method of the boom hydraulic control system according to claim 11, characterized in that: The boom hydraulic control system also includes a first pipeline, one end of the first pipeline is used to communicate with the first oil port of the main oil circuit, the other end of the first pipeline is connected to the rod chamber of the boom boom cylinder, and the second oil port of the first solenoid valve is connected to the rod chamber of the boom boom cylinder and the first oil port of the main oil circuit through the first pipeline.

13. The control method of the boom hydraulic control system according to claim 11, characterized in that: The boom hydraulic control system also includes a second pipeline, one end of the second pipeline is used to communicate with the second oil port of the main oil circuit, the other end of the second pipeline is connected to the rodless chamber of the boom telescopic cylinder, and the second oil port of the second solenoid valve is connected to the rodless chamber of the boom telescopic cylinder and the second oil port of the main oil circuit through the second pipeline.

14. The control method of the boom hydraulic control system according to claim 11, characterized in that: The boom hydraulic control system further includes a third pipeline and a fourth pipeline, one end of the third pipeline is used to communicate with the third oil port of the main oil circuit, and the other end of the third pipeline is communicated with the first oil port of the turntable drive motor; one end of the fourth pipeline is communicated with the fourth oil port of the main oil circuit, and the other end of the fourth pipeline is communicated with the second oil port of the turntable drive motor; Wherein, the third solenoid valve is arranged on the third pipeline or the fourth pipeline.

15. The control method of the boom hydraulic control system according to claim 14, characterized in that: The main oil circuit includes a first relief valve, a first oil port of the first relief valve is connected to a third oil port of the main oil circuit, and a second oil port of the first relief valve is connected to an oil tank of the main oil circuit; The main oil circuit includes a second overflow valve, a first oil port of the second overflow valve is communicated with a fourth oil port of the main oil circuit, and a second oil port of the second overflow valve is communicated with an oil tank of the main oil circuit.

16. An aerial work vehicle, characterized in that: The control method of the boom hydraulic control system according to any one of claims 1 to 15 is applied.

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