Hydraulic levelling device, hydraulic levelling method and aerial work platform

Abstract

The application belongs to the technical field of aerial work platforms, and discloses a hydraulic leveling device, a hydraulic leveling method and an aerial work platform. The first axle pipe of the hydraulic leveling device is connected with the rod cavity of the first leveling oil cylinder and the rodless cavity of the second leveling oil cylinder. The second axle pipe is connected with the rodless cavity of the first leveling oil cylinder and the rod cavity of the second leveling oil cylinder. The electromagnetic control valve group is connected with the first axle pipe, the second axle pipe, the oil supply pipe and the oil return pipe. The electromagnetic control valve group has a communication state and a disconnection state. When the electromagnetic control valve group is in the communication state, the first axle pipe and the second axle pipe are connected with the oil supply pipe, and the chassis can be automatically leveled. The application is suitable for the situation that the leveling requirement of the chassis is not high, and the electromagnetic valve and the oil cylinder are prevented from frequently starting and stopping. When the electromagnetic control valve group is in the disconnection state, the first axle pipe and the second axle pipe are connected with the oil return pipe, and the automatic leveling is not performed.

Description

Technical Field

[0001] This invention relates to the field of aerial work platform technology, and more particularly to a hydraulic leveling device, a hydraulic leveling method, and an aerial work platform. Background Technology

[0002] When an aerial work platform vehicle travels on a bumpy road, the axle may tilt. Currently, a hydraulic leveling device is typically used to level the vehicle chassis. Specifically, two floating cylinders are installed at each end of the axle, with the ends of both cylinders furthest from the axle connected to the chassis. Figure 1 As shown, the two floating cylinders are a left floating cylinder 1 and a right floating cylinder 2. The rod chamber of the left floating cylinder 1 and the rodless chamber of the right floating cylinder 2 are connected through a first pipeline 3. The rodless chamber of the left floating cylinder 1 and the rod chamber of the right floating cylinder 2 are connected through a second pipeline 4. The lever valve 5 is simultaneously connected to the first pipeline 3, the second pipeline 4, the inlet oil pipe 6, and the return oil pipe 7. The lever valve 5 has an initial state, a first leveling state, and a second leveling state. When the lever valve 5 is in the initial state, the first pipeline 3, the second pipeline 4, the inlet oil pipe 6, and the return oil pipe 7 are all disconnected. If the vehicle tilts to the left, the lever valve 5 can be controlled to enter the first leveling state. At this time, the oil inlet pipe 6 is connected to the second pipe 4, and the oil return pipe 7 is connected to the first pipe 3. The oil flows through the second pipe 4 into the rodless chamber of the left floating cylinder 1 and the rod chamber of the right floating cylinder 2, thereby causing the piston of the left floating cylinder 1 to extend. Simultaneously, the piston of the right floating cylinder 2 retracts, and the right floating cylinder 2 shortens, thus leveling the vehicle chassis. If the vehicle tilts to the right, the lever valve 5 can be controlled to enter the second leveling state. At this time, the oil inlet pipe 6 is connected to the first pipe 3, and the oil return pipe 7 is connected to the second pipe 4. The oil flows through the first pipe 3 into the rod chamber of the left floating cylinder 1 and the rodless chamber of the right floating cylinder 2, thereby causing the piston of the left floating cylinder 1 to retract, and the left floating cylinder 1 shortens. Simultaneously, the piston of the right floating cylinder 2 extends, and the right floating cylinder 2 lengthens, thus leveling the vehicle chassis. The above structure can level the vehicle chassis when the boom of the aerial work platform is extended and put into working condition to maintain the stability of the boom. However, when the boom is retracted, the leveling requirement of the vehicle chassis is lower, and this solution will lead to energy waste. In addition, if the aerial work platform is traveling at a high speed on uneven road surfaces, the lever valve 5 will frequently switch working states, and at the same time, it will cause the two floating cylinders to frequently extend or retract, reducing the overall service life of the hydraulic leveling device. Summary of the Invention

[0003] According to one aspect of the present invention, the present invention provides a hydraulic leveling device to solve the problems of energy waste caused by the prior art leveling device when the boom is retracted, and frequent start and stop of the lever valve and two floating cylinders when the aerial work platform is traveling at high speed, which reduces the overall service life of the leveling device.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A hydraulic leveling device for leveling the chassis of an aerial work platform vehicle, characterized in that it comprises:

[0006] The first leveling cylinder is located at one end on the chassis and at the other end on the left end of the first axle of the aerial work vehicle.

[0007] The second leveling cylinder is located at one end on the chassis and at the other end on the right end of the first axle of the aerial work vehicle.

[0008] The first axle pipeline is connected to both the rod chamber of the first leveling cylinder and the rodless chamber of the second leveling cylinder.

[0009] The second axle pipeline is connected to both the rodless chamber of the first leveling cylinder and the rod chamber of the second leveling cylinder.

[0010] The electromagnetic control valve assembly is connected to the first axle pipeline, the second axle pipeline, the oil supply pipeline, and the oil return pipeline. The electromagnetic control valve assembly has an on-state and an off-state. When the electromagnetic control valve assembly is in the on-state, both the first axle pipeline and the second axle pipeline are connected to the oil supply pipeline. When the electromagnetic control valve assembly is in the off-state, both the first axle pipeline and the second axle pipeline are connected to the oil return pipeline.

[0011] As a preferred embodiment of the hydraulic leveling device, the electromagnetic control valve group also has a first leveling state and a second leveling state. When the electromagnetic control valve group is in the first leveling state, the oil supply line is connected to the first axle line and the oil return line is connected to the second axle line. When the electromagnetic control valve group is in the second leveling state, the oil supply line is connected to the second axle line and the oil return line is connected to the first axle line.

[0012] As a preferred option for the hydraulic leveling device, it also includes:

[0013] The third leveling cylinder is located at one end on the chassis and at the other end on the left end of the second axle of the aerial work platform vehicle.

[0014] The fourth leveling cylinder is located at one end on the chassis and at the other end on the right end of the second axle of the aerial work vehicle.

[0015] The third axle pipeline is connected to both the rod chamber of the third leveling cylinder and the rodless chamber of the fourth leveling cylinder.

[0016] The fourth axle pipeline connects to both the rodless chamber of the third leveling cylinder and the rod chamber of the fourth leveling cylinder.

[0017] A first solenoid valve is connected to the third axle pipeline, the fourth axle pipeline, the oil supply pipeline, and the oil return pipeline. The first solenoid valve has an initial state, a first reversing state, and a second reversing state. When the first solenoid valve is in the initial state, both the third axle pipeline and the fourth axle pipeline are connected to the oil return pipeline. When the first solenoid valve is in the first reversing state, the oil supply pipeline is connected to the third axle pipeline, and the oil return pipeline is connected to the fourth axle pipeline. When the first solenoid valve is in the second reversing state, the oil supply pipeline is connected to the fourth axle pipeline, and the oil return pipeline is connected to the third axle pipeline.

[0018] According to another aspect of the present invention, a hydraulic leveling method is provided for application to the aforementioned hydraulic leveling device, the hydraulic leveling method comprising:

[0019] Obtain the boom angle of the aerial work vehicle;

[0020] Compare the boom angle with the preset angle;

[0021] If the boom angle is not greater than the preset angle, then the electromagnetic control valve group is controlled to enter the connected state.

[0022] This invention also provides a hydraulic leveling method applied to the aforementioned hydraulic leveling device, the hydraulic leveling method comprising:

[0023] Obtain the boom angle of the aerial work vehicle;

[0024] Compare the boom angle with the preset angle;

[0025] If the boom angle is greater than the preset angle, then the following steps are performed:

[0026] Detect the tilt state of the chassis;

[0027] If the chassis is detected to be tilted to the right front, the electromagnetic control valve group is controlled to enter the first leveling state.

[0028] If the chassis is detected to be tilted to the left front, the electromagnetic control valve group is controlled to enter the second leveling state.

[0029] As a preferred embodiment of the hydraulic leveling method, if the chassis is detected to be tilted to the right rear, the first solenoid valve is controlled to enter the first reversing state.

[0030] If the chassis is detected to be tilted to the left rear, the first solenoid valve is controlled to enter the second reversing state.

[0031] As a preferred embodiment of the hydraulic leveling method, if the chassis is detected to be tilted to the right, the electromagnetic control valve group is controlled to enter the first leveling state, and the first electromagnetic valve is controlled to enter the first reversing state.

[0032] If the chassis is detected to be tilted to the left, the electromagnetic control valve group is controlled to enter the second leveling state, and the first electromagnetic valve is controlled to enter the second reversing state.

[0033] As a preferred embodiment of the hydraulic leveling method, the hydraulic leveling device further includes a first tilt angle detection unit and a second tilt angle detection unit. The first tilt angle detection unit is used to detect the tilt state of the chassis in the left-right direction, and the second tilt angle detection unit is used to detect the tilt state of the chassis in the front-back direction.

[0034] In the hydraulic leveling method, detecting the tilt state of the chassis includes:

[0035] The first tilt angle detection unit detects the tilt state of the chassis in the left-right direction, and the second tilt angle detection unit detects the tilt state of the chassis in the front-back direction.

[0036] If the first tilt detection unit detects that the chassis is tilted to the right and the second tilt detection unit detects that the chassis is tilted forward, then it is determined that the chassis is tilted to the right front.

[0037] If the first tilt detection unit detects that the chassis is tilted to the left and the second tilt detection unit detects that the chassis is tilted forward, then it is determined that the chassis is tilted to the left front.

[0038] As a preferred embodiment of the hydraulic leveling method, if the boom angle is greater than the preset angle, the wheel contact state is detected simultaneously when detecting the tilt state of the chassis.

[0039] If the right front wheel is not in contact with the ground, the electromagnetic control valve group is controlled to enter the first leveling state.

[0040] If the left front wheel is detected not to be in contact with the ground, the electromagnetic control valve group is controlled to enter the second leveling state. According to another aspect of the invention, an aerial work platform is provided, including the aforementioned hydraulic leveling device. The aerial work platform further includes a chassis, a first axle, and a hydraulic system. The hydraulic system includes an oil tank, a supply pump, a supply line, and a return line. The oil tank is used to store hydraulic oil. The inlet end of the supply pump is connected to the oil tank, the outlet end is connected to the supply line, and the return line is connected to the oil tank.

[0041] The beneficial effects of this invention are:

[0042] The present invention provides a hydraulic leveling device, including a first leveling cylinder, a second leveling cylinder, a first axle pipeline, a second axle pipeline, and an electromagnetic control valve group. One end of the first leveling cylinder is disposed on the chassis, and the other end is disposed on the left end of the first axle. One end of the second leveling cylinder is disposed on the chassis, and the other end is disposed on the right end of the first axle. The tilt angle of the chassis can be adjusted by adjusting the extension of the two leveling cylinders. The first axle pipeline connects to both the rod-side chamber of the first leveling cylinder and the rodless chamber of the second leveling cylinder. The second axle pipeline connects to both the rodless chamber of the first leveling cylinder and the rod-side chamber of the second leveling cylinder. The electromagnetic control valve assembly connects to the first axle pipeline, the second axle pipeline, the oil supply pipeline, and the oil return pipeline. The electromagnetic control valve assembly has an on / off state. When the electromagnetic control valve assembly is in the on / off state, both the first and second axle pipelines are connected to the oil supply pipeline. At this time, oil simultaneously enters both the first and second axle pipelines and then enters the rod-side and rodless chambers of the first leveling cylinder and the second leveling cylinder. The leveling cylinder has rod-side and rodless chambers. Under these conditions, the chassis can automatically level itself. For example, if the vehicle's right wheel travels over a pothole, the right wheel experiences less force, and the first axle tilts to the right, while the left wheel experiences greater force. This causes the first leveling cylinder located on the left end of the first axle to retract under pressure. Oil then flows sequentially through the second axle piping, the solenoid control valve assembly, and the first axle piping, causing the second leveling cylinder located on the right end of the first axle to extend, thus achieving automatic leveling. If the vehicle's left wheel travels over a pothole, the second leveling cylinder retracts under pressure, and the first leveling cylinder extends, similarly achieving automatic leveling. When the solenoid control valve assembly is in the off state, both the first and second axle piping are connected to the return oil line, and automatic leveling no longer occurs. This hydraulic leveling device can automatically level the chassis when the leveling requirements are not high, thereby avoiding energy waste and frequent start-stop of solenoid valves and cylinders. It can be used for boom retraction of aerial work platforms and chassis leveling when the aerial work platform is in motion.

[0043] The present invention also provides a hydraulic leveling method applied to the above-mentioned hydraulic leveling device. The hydraulic leveling method includes obtaining the boom angle of the aerial work platform vehicle, comparing the boom angle with a preset angle, and if the boom angle is not greater than the preset angle, it indicates that the boom is in a retracted state and not working. At this time, the chassis leveling requirement is not high. Therefore, the electromagnetic control valve group is controlled to enter the connected state, so that the oil simultaneously enters the first axle pipeline and the second axle pipeline, and enters the rod-side and rodless-side chambers of the first leveling cylinder and the rod-side and rodless-side chambers of the second leveling cylinder, automatically leveling the chassis, thereby avoiding energy waste and frequent start-stop of the electromagnetic valve and cylinder.

[0044] The present invention also provides an aerial work platform vehicle, including the above-mentioned hydraulic leveling device. The hydraulic leveling device can automatically level the chassis when the chassis leveling requirements are not high, thereby avoiding energy waste and avoiding frequent start and stop of solenoid valves and cylinders. It is applicable to the boom retraction of the aerial work platform vehicle and the chassis leveling when the aerial work platform vehicle is in motion. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of a hydraulic leveling device in the prior art;

[0046] Figure 2 This is a schematic diagram of the hydraulic leveling device in an embodiment of the present invention;

[0047] Figure 3 This is a partial structural schematic diagram of the aerial work platform vehicle in an embodiment of the present invention;

[0048] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0049] Figure 5 This is a schematic diagram of the chassis and the first axle in an embodiment of the present invention;

[0050] Figure 6 This is a structural schematic diagram of the chassis and the second axle in an embodiment of the present invention;

[0051] Figure 7 This is a flowchart of the hydraulic leveling method in an embodiment of the present invention.

[0052] In the picture:

[0053] 1. Left floating cylinder; 2. Left floating cylinder; 3. First pipeline; 4. Second pipeline; 5. Rod valve; 6. Inlet oil pipe; 7. Return oil pipe;

[0054] 100. Chassis; 200. First axle; 300. Second axle;

[0055] 11. First leveling cylinder; 12. Second leveling cylinder; 13. First axle piping; 14. Second axle piping;

[0056] 20. Electromagnetic control valve assembly; 21. Third solenoid valve; 22. Fourth solenoid valve; 23. Connecting pipeline;

[0057] 31. Oil supply line; 311. First oil supply line section; 312. Second oil supply line section; 32. Return line; 33. Overflow valve;

[0058] 41. Third leveling cylinder; 42. Fourth leveling cylinder; 43. Third axle piping; 44. Fourth axle piping;

[0059] 51. First solenoid valve; 52. Second solenoid valve;

[0060] 60. Pressure sensor;

[0061] 70. Balancing valve;

[0062] 80. Tilt sensor. Detailed Implementation

[0063] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0064] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0065] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0066] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0067] Example 1

[0068] This embodiment provides a hydraulic leveling device to solve the problems in the prior art where the leveling device wastes energy when the boom is retracted, and where the lever valve and two floating cylinders frequently start and stop when the aerial work platform is traveling at high speed, reducing the overall service life of the leveling device. It can be used in the field of aerial work platform technology.

[0069] Reference Figures 2-6 The hydraulic leveling device is used to level the chassis 100 of the aerial work platform vehicle. The hydraulic leveling device includes a first leveling cylinder 11, a second leveling cylinder 12, a first axle pipeline 13, and a second axle pipeline 14. One end of the first leveling cylinder 11 is located on the chassis 100, and the other end is located on the left end of the first axle 200 of the aerial work platform vehicle. One end of the second leveling cylinder 12 is located on the chassis 100, and the other end is located on the right end of the first axle 200 of the aerial work platform vehicle. The tilt angle of the chassis 100 can be adjusted by adjusting the extension of the two leveling cylinders. Specifically, in this embodiment, one end of the rodless chamber of the first leveling cylinder 11 is connected to the chassis 100, and one end of the rod chamber is connected to the left end of the first axle 200; one end of the rodless chamber of the second leveling cylinder 12 is connected to the chassis 100, and one end of the rod chamber is connected to the right end of the first axle 200. The first axle pipe 13 is connected to both the rod chamber of the first leveling cylinder 11 and the rodless chamber of the second leveling cylinder 12; the second axle pipe 14 is connected to both the rodless chamber of the first leveling cylinder 11 and the rod chamber of the second leveling cylinder 12.

[0070] Continue to refer to Figures 2-6 The hydraulic leveling device also includes an electromagnetic control valve group 20, which is simultaneously connected to the first axle pipeline 13, the second axle pipeline 14, the oil supply pipeline 31, and the oil return pipeline 32. The electromagnetic control valve group 20 has a connected state and a disconnected state.

[0071] When the electromagnetic control valve group 20 is in the connected state, both the first axle pipeline 13 and the second axle pipeline 14 are connected to the oil supply pipeline 31. At this time, oil simultaneously enters the first axle pipeline 13 and the second axle pipeline 14, and enters the rod-side and rodless-side chambers of the first leveling cylinder 11 and the rod-side and rodless-side chambers of the second leveling cylinder 12. At this time, the chassis 100 can automatically level itself. For example, if the right wheel of the vehicle travels to a pothole on the road, the right wheel experiences less force, and the first axle 200 tilts to the right, while the left wheel experiences greater force. This allows the oil supply to the first axle to be adjusted. The first leveling cylinder 11 at the left end of the first axle 200 retracts under pressure, and the hydraulic fluid flows sequentially through the second axle pipeline 14, the solenoid control valve group 20, and the first axle pipeline 13, causing the second leveling cylinder 12 located at the right end of the first axle 200 to extend, thereby achieving automatic leveling. Specifically, the hydraulic fluid flows out from the rodless chamber of the first leveling cylinder 11 and the rod chamber of the second leveling cylinder 12, and enters the first axle pipeline 13 through the second axle pipeline 14 and the solenoid control valve group 20, and then enters the rod chamber of the first leveling cylinder 11 and the rodless chamber of the second leveling cylinder 12. If the left wheel of the vehicle travels to a pothole in the road surface, the second leveling cylinder 12 retracts under pressure, and the first leveling cylinder 11 extends, which also enables automatic leveling.

[0072] When the electromagnetic control valve group 20 is in the off state, both the first axle pipeline 13 and the second axle pipeline 14 are connected to the return oil pipeline 32. At this time, the pressure in the rod-side and rodless-side chambers of the first leveling cylinder 11 and the rod-side and rodless-side chambers of the second leveling cylinder 12 are both 0. This hydraulic leveling device allows the chassis 100 to tilt adaptively according to road conditions when the leveling requirements are not high, thus avoiding energy waste and frequent starting and stopping of the electromagnetic valve and cylinders. It can be used for boom retraction of aerial work platforms and for leveling the chassis 100 while the aerial work platform is in motion.

[0073] It is understandable that when the electromagnetic control valve group 20 is in the connected state, the automatic leveling is achieved only by the first leveling cylinder 11 or the second leveling cylinder 12 being pressurized. The leveling effect is not significant compared to the existing technology. However, for aerial work platforms that are not in operation or traveling at high speed, the leveling effect of this hydraulic leveling device can meet the actual driving needs. When the boom is deployed for high-altitude operations, the leveling effect of the hydraulic leveling device cannot meet the operational needs. To address this, the electromagnetic control valve group 20 also has a first leveling state and a second leveling state. When the electromagnetic control valve group 20 is in the first leveling state, the oil supply line 31 is connected to the first axle line 13, and the oil return line 32 is connected to the second axle line 14. Hydraulic oil is supplied to the first axle line 13 through the oil supply line 31, so that the oil flows into the rod chamber of the first leveling cylinder 11 and the rodless chamber of the second leveling cylinder 12, thereby causing the first leveling cylinder 11 to shorten and the second leveling cylinder 12 to extend. This is applicable to situations where the first axle 200 is tilted to the right, and is used to level the chassis 100. When the electromagnetic control valve group 20 is in the second leveling state, the oil supply line 31 is connected to the second axle line 14, and the oil return line 32 is connected to the first axle line 13. Hydraulic oil is supplied to the second axle line 14 through the oil supply line 31 so that the oil flows into the rodless chamber of the first leveling cylinder 11 and the rod chamber of the second leveling cylinder 12, thereby causing the first leveling cylinder 11 to extend and the second leveling cylinder 12 to shorten. This is applicable to situations where the first axle 200 is tilted to the left, and is used to level the chassis 100.

[0074] In this embodiment, the first axle 200 is the front axle of the vehicle, the first leveling state of the electromagnetic control valve group 20 is suitable for the situation where the vehicle is tilted to the right front, and the second leveling state of the electromagnetic control valve group 20 is suitable for the situation where the vehicle is tilted to the left front.

[0075] Continue to refer to Figures 2-6The hydraulic leveling device also includes a third leveling cylinder 41, a fourth leveling cylinder 42, a third axle pipe 43, a fourth axle pipe 44, and a first solenoid valve 51. One end of the third leveling cylinder 41 is located on the chassis 100, and the other end is located on the left end of the second axle 300 of the aerial work platform vehicle. One end of the fourth leveling cylinder 42 is located on the chassis 100, and the other end is located on the right end of the second axle 300 of the aerial work platform vehicle, wherein the second axle 300 is the rear axle of the vehicle. The third axle pipe 43 connects to both the rod-side chamber of the third leveling cylinder 41 and the rodless chamber of the fourth leveling cylinder 42; the fourth axle pipe 44 connects to both the rodless chamber of the third leveling cylinder 41 and the rod-side chamber of the fourth leveling cylinder 42. The first solenoid valve 51 is simultaneously connected to the third axle pipeline 43, the fourth axle pipeline 44, the oil supply pipeline 31, and the return oil pipeline 32. The first solenoid valve 51 has an initial state, a first reversing state, and a second reversing state. When the first solenoid valve 51 is in the initial state, the third axle pipeline 43 and the fourth axle pipeline 44 are both connected to the return oil pipeline 32. At this time, the third leveling cylinder 41 and the fourth leveling cylinder 42 remain stationary and do not perform leveling actions. When the first solenoid valve 51 is in the first reversing state, the oil supply line 31 is connected to the third axle line 43, and the oil return line 32 is connected to the fourth axle line 44. The oil enters the third axle line 43 through the oil supply line 31, and enters the rod chamber of the third leveling cylinder 41 and the rodless chamber of the fourth leveling cylinder 42, so as to drive the third leveling cylinder 41 to shorten and the fourth leveling cylinder 42 to extend. This can be used when the second axle 300 is tilted to the right, that is, when the vehicle is tilted to the right rear, to level the chassis 100. When the first solenoid valve 51 is in the second reversing state, the oil supply line 31 is connected to the fourth axle line 44, and the oil return line 32 is connected to the third axle line 43. Oil enters the fourth axle line 44 through the oil supply line 31, and then enters the rodless chamber of the third leveling cylinder 41 and the rod chamber of the fourth leveling cylinder 42, causing the third leveling cylinder 41 to extend and the fourth leveling cylinder 42 to shorten. This is suitable for situations where the second axle 300 is tilted to the left, i.e., the vehicle is tilted to the left rear, for leveling the chassis 100. The first solenoid valve 51 is a three-position four-way solenoid valve with left, middle, and right positions. When the first solenoid valve 51 is in the left position, it is in the first reversing state; when it is in the middle position, it is in the initial state; and when it is in the right position, it is in the second reversing state.

[0076] Optionally, the oil supply line 31 includes a first oil supply line section 311 and a second oil supply line section 312, wherein the first oil supply line section 311 is connected to the supply pump, and the second oil supply line section 312 is connected to the solenoid control valve group 20 and the first solenoid valve 51. The hydraulic leveling device also includes a second solenoid valve 52, which is connected to the first oil supply line section 311, the second oil supply line section 312, and the return line 32. The second solenoid valve 52 is a two-position three-way solenoid valve with a left position and a right position. When the second solenoid valve 52 is in the left position, the second oil supply line section 312 is connected to the return line 32, and the hydraulic leveling device does not participate in leveling. When the second solenoid valve 52 is in the right position, the first oil supply line section 311 is connected to the second oil supply line section 312, and the hydraulic leveling device can participate in leveling.

[0077] Optionally, an overflow valve 33 is provided between the first oil supply pipe section 311 and the return oil line 32. The overflow valve 33 is used to discharge excess oil in the first oil supply pipe section 311 to the return oil line 32.

[0078] Optionally, the electromagnetic control valve assembly 20 specifically includes a third solenoid valve 21, a fourth solenoid valve 22, and a connecting pipeline 23. The third solenoid valve 21 is a three-position four-way solenoid valve, simultaneously connected to the second oil supply line section 312, the connecting pipeline 23, the first axle pipeline 13, and the second axle pipeline 14. The third solenoid valve 21 has left, middle, and right positions. When the third solenoid valve 21 is in the left position, the second oil supply line section 312 is connected to the first axle pipeline 13, and the connecting pipeline 23 is connected to the second axle pipeline 14. When the third solenoid valve 21 is in the middle position, the connecting pipeline 23 is simultaneously connected to both the first axle pipeline 13 and the second axle pipeline 14. When the third solenoid valve 21 is in the right position, the second oil supply line section 312 is connected to the second axle pipeline 14, and the connecting pipeline 23 is connected to the first axle pipeline 13. Furthermore, the fourth solenoid valve 22 is a two-position three-way solenoid valve, simultaneously connected to the connecting pipe 23, the second oil supply pipe section 312, and the return oil pipe 32. The fourth solenoid valve 22 has a left position and a right position. When the fourth solenoid valve 22 is in the left position, the connecting pipe 23 is connected to the return oil pipe 32; when the fourth solenoid valve 22 is in the right position, the second oil supply pipe section 312 is connected to the connecting pipe 23. In this electromagnetic control valve group 20, if the third solenoid valve 21 is in the middle position and the fourth solenoid valve 22 is in the left position, then both the first axle pipe 13 and the second axle pipe 14 are connected to the return oil pipe 32, and the electromagnetic control valve group 20 is in the open state; if the third solenoid valve 21 is in the middle position and the fourth solenoid valve 22 is in the right position, then both the first axle pipe 13 and the second axle pipe 14 are connected to the second oil supply pipe section 312, and the electromagnetic control valve group 20 is in the connected ... When valve 21 is in the left position and the fourth solenoid valve 22 is in the left position, the second oil supply line 312 is connected to the first axle line 13, and the return line 32 is connected to the second axle line 14. At this time, the solenoid control valve group 20 is in the first leveling state. If the third solenoid valve 21 is in the right position and the fourth solenoid valve 22 is in the left position, the second oil supply line 312 is connected to the second axle line 14, and the return line 32 is connected to the first axle line 13. At this time, the solenoid control valve group 20 is in the second leveling state.

[0079] Optionally, the first leveling cylinder 11, the second leveling cylinder 12, the third leveling cylinder 41, and the fourth leveling cylinder 42 are all connected to a balance valve 70. The following explanation uses the balance valve 70 connected to the first leveling cylinder 11 as an example to illustrate its function. Specifically, the balance valve 70 connects the first axle pipe 13 to the rod-side chamber of the first leveling cylinder 11, and the second axle pipe 14 to the rodless chamber of the first leveling cylinder 11, allowing hydraulic fluid to enter. Furthermore, after hydraulic fluid has entered and leveling is completed, the balance valve 70 disconnects the connection to maintain the oil pressure within the first leveling cylinder 11, preventing further hydraulic oil flow and maintaining the leveled state. The balance valve 70 is a relatively common technology in the field, and its specific structure and principle will not be elaborated further.

[0080] Example 2

[0081] This embodiment provides a hydraulic leveling method, applied to the hydraulic leveling device in the above embodiments, with reference to... Figure 7 The hydraulic leveling method includes the following steps.

[0082] S1000: Obtain the boom angle of the aerial work platform vehicle.

[0083] The boom is the lifting device of an aerial work platform. The boom angle is the angle between the center line of the boom and the front-rear direction of the vehicle. Alternatively, the boom can be placed close to the boom storage platform and can rotate relative to the surface of the boom storage platform to complete the boom deployment. The boom angle is the angle between the center line of the boom and the surface of the boom storage platform.

[0084] S1100: Compare the boom angle with the preset angle.

[0085] In this embodiment, the preset angle is 0°, while in other embodiments, the preset angle can be other values, such as 1°, 2° or 3°.

[0086] If the boom angle is not greater than the preset angle, then step S1200 is executed; if the boom angle is greater than the preset angle, then steps S2000 and S3000 are executed simultaneously.

[0087] S1200: Controls the solenoid control valve group 20 to enter the connected state.

[0088] If the boom angle is not greater than the preset angle, it indicates that the boom is not in the extended state and is not working. At this time, the leveling requirement for the chassis 100 is not high. Therefore, the solenoid control valve group 20 is activated, allowing oil to simultaneously enter the first axle pipeline 13 and the second axle pipeline 14, and then into the rod-side and rodless-side chambers of the first leveling cylinder 11 and the second leveling cylinder 12, automatically leveling the chassis 100. This avoids energy waste and frequent starting and stopping of the solenoid valves and cylinders. This control scheme is suitable for situations where the aerial work platform is traveling at high or low speeds.

[0089] S2000: Detects the tilt status of chassis 100.

[0090] In this embodiment, the first axle 200 is the front axle of the vehicle, and the second axle 300 is the rear axle of the vehicle. In other embodiments, the first axle 200 may be the rear axle of the vehicle, and the second axle 300 may be the front axle of the vehicle, or the vehicle may have multiple axles, with the first axle 200 and the second axle 300 being two of them.

[0091] If the chassis 100 is detected to be tilted to the right front, proceed to step S2100; if the chassis 100 is detected to be tilted to the left front, proceed to step S2200; if the chassis 100 is detected to be tilted to the right rear, proceed to step S2300; if the chassis 100 is detected to be tilted to the left rear, proceed to step S2400; if the chassis 100 is detected to be tilted to the right, proceed to step S2500; if the chassis 100 is detected to be tilted to the left, proceed to step S2600.

[0092] Specifically, detecting a rightward tilt of the chassis 100 means detecting that the angle of tilt of the chassis 100 along the longitudinal direction of the vehicle body is less than the calibrated angle, and that the chassis 100 is tilted to the right along the lateral direction of the vehicle body; detecting a leftward tilt of the chassis 100 means detecting that the angle of tilt of the chassis 100 along the longitudinal direction of the vehicle body is less than the calibrated angle, and that the chassis 100 is tilted to the left along the lateral direction of the vehicle body. In this embodiment, the calibrated angle is 1°.

[0093] Optionally, the hydraulic leveling device further includes a first tilt angle detection unit and a second tilt angle detection unit. The first tilt angle detection unit is used to detect the tilt state of the chassis in the left-right direction, and the second tilt angle detection unit is used to detect the tilt state of the chassis in the front-back direction. In this embodiment, a tilt angle sensor 80 with two detection axes is used. One detection axis of the tilt angle sensor 80 is the first tilt angle detection unit, and the other detection axis is the second tilt angle detection unit. The tilt angle sensor 80 is arranged in the aerial work platform as follows: Figures 3-4As shown. In other embodiments, two tilt sensors can be provided, one as a first tilt detection unit to detect the tilt state of the chassis 100 in the left-right direction, and the other as a second tilt detection unit to detect the tilt state of the chassis 100 in the front-back direction.

[0094] In step S2000, detecting the tilt state of the chassis 100 includes:

[0095] The first tilt angle detection unit detects the tilt of the chassis 100 in the left-right direction, and the second tilt angle detection unit detects the tilt of the chassis 100 in the front-back direction.

[0096] If the first tilt detection unit detects that the chassis 100 is tilted to the right, and the second tilt detection unit detects that the chassis 100 is tilted forward, then it is determined that the chassis 100 is tilted to the right front.

[0097] If the first tilt detection unit detects that the chassis 100 is tilted to the left, and the second tilt detection unit detects that the chassis 100 is tilted forward, then it is determined that the chassis 100 is tilted to the left front.

[0098] If the first tilt detection unit detects that the chassis 100 is tilted to the right, and the second tilt detection unit detects that the chassis 100 is tilted to the rear, then it is determined that the chassis 100 is tilted to the right rear.

[0099] If the first tilt detection unit detects that the chassis 100 is tilted to the left and the second tilt detection unit detects that the chassis 100 is tilted to the rear, then it is determined that the chassis 100 is tilted to the left rear.

[0100] If the first tilt detection unit detects that the chassis 100 is tilted to the right, and the second tilt detection unit detects that the tilt angle of the chassis 100 in the front-rear direction is less than the calibrated angle, then it is determined that the chassis 100 is tilted to the right.

[0101] If the first tilt detection unit detects that the chassis 100 is tilted to the left, and the second tilt detection unit detects that the tilt angle of the chassis 100 in the front-rear direction is less than the calibrated angle, then it is determined that the chassis 100 is tilted to the left.

[0102] S2100: Controls the solenoid control valve group 20 to enter the first leveling state.

[0103] If the chassis 100 is detected to be tilted to the right front, the control solenoid valve group 20 is put into the first leveling state. The oil supply line 31 is connected to the first axle line 13, and the oil return line 32 is connected to the second axle line 14. Hydraulic oil is supplied to the first axle line 13 through the oil supply line 31 so that the oil flows into the rod chamber of the first leveling cylinder 11 and the rodless chamber of the second leveling cylinder 12, thereby causing the first leveling cylinder 11 to shorten and the second leveling cylinder 12 to extend, thereby causing the chassis 100 to return to the center.

[0104] S2200: Controls the solenoid control valve group 20 to enter the second leveling state.

[0105] If the chassis 100 is detected to be tilted to the left front, the control solenoid valve group 20 is put into the second leveling state. The oil supply line 31 is connected to the second axle line 14, and the oil return line 32 is connected to the first axle line 13. Hydraulic oil is supplied to the second axle line 14 through the oil supply line 31 so that the oil flows into the rodless chamber of the first leveling cylinder 11 and the rod chamber of the second leveling cylinder 12, thereby causing the first leveling cylinder 11 to extend and the second leveling cylinder 12 to shorten, thereby causing the chassis 100 to return to the center.

[0106] S2300: Controls the first solenoid valve 51 to enter the first reversing state.

[0107] If the chassis 100 is detected to be tilted to the right rear, the first solenoid valve 51 is controlled to enter the first reversing state. The oil supply line 31 is connected to the third axle line 43, and the oil return line 32 is connected to the fourth axle line 44. The oil enters the third axle line 43 through the oil supply line 31, and enters the rod chamber of the third leveling cylinder 41 and the rodless chamber of the fourth leveling cylinder 42, so as to drive the third leveling cylinder 41 to shorten and the fourth leveling cylinder 42 to extend, thereby driving the chassis 100 to return to the center.

[0108] S2400: Controls the first solenoid valve 51 to enter the second reversing state.

[0109] If the chassis 100 is detected to be tilted to the left rear, the first solenoid valve 51 is controlled to enter the second reversing state. The oil supply line 31 is connected to the fourth axle line 44, and the oil return line 32 is connected to the third axle line 43. The oil enters the fourth axle line 44 through the oil supply line 31, and enters the rodless chamber of the third leveling cylinder 41 and the rod chamber of the fourth leveling cylinder 42, so as to drive the third leveling cylinder 41 to extend and the fourth leveling cylinder 42 to shorten, thereby driving the chassis 100 to return to the center.

[0110] S2500: Controls the solenoid control valve group 20 to enter the first leveling state and controls the first solenoid valve 51 to enter the first reversing state.

[0111] If the chassis 100 is detected to be tilted to the right, the solenoid control valve group 20 is controlled to enter the first leveling state, and the first solenoid valve 51 is controlled to enter the first reversing state, so as to drive the first leveling cylinder 11 to shorten, the second leveling cylinder 12 to extend, and simultaneously drive the third leveling cylinder 41 to shorten and the fourth leveling cylinder 42 to extend, thereby driving the chassis 100 to return to the upright position.

[0112] S2600: Controls the solenoid control valve group 20 to enter the second leveling state and controls the first solenoid valve 51 to enter the second reversing state.

[0113] If the chassis 100 is detected to be tilted to the left, the solenoid control valve group 20 is controlled to enter the second leveling state, and the first solenoid valve 51 is controlled to enter the second reversing state, so as to drive the first leveling cylinder 11 to extend, the second leveling cylinder 12 to shorten, and simultaneously drive the third leveling cylinder 41 to extend and the fourth leveling cylinder 42 to shorten, thereby driving the chassis 100 to return to the upright position.

[0114] S3000: Detects the contact status of the wheels with the ground.

[0115] When executing step S2000, step S3000 is executed simultaneously. Specifically, the detection of wheel contact status can be achieved through pressure sensors 60. Four pressure sensors 60 are provided, and the four pressure sensors 60 are respectively connected to the first leveling cylinder 11, the second leveling cylinder 12, the third leveling cylinder 41, and the fourth leveling cylinder 42. The following description only uses the pressure sensor 60 connected to the first leveling cylinder 11 as an example. This pressure sensor 60 is used to detect the pressure exerted by the chassis 100 on the rodless end of the first leveling cylinder 11, or the pressure exerted by the first axle 200 on the rod end of the first leveling cylinder 11. If the left front wheel is in contact with the ground, the pressure value detected by the pressure sensor 60 is larger; if the left front wheel is not in contact with the ground, the pressure value detected by the pressure sensor 60 is smaller. The arrangement of the pressure sensors 60 in the aerial work platform vehicle is as follows: Figures 3-4 As shown.

[0116] Specifically, if the pressure sensor 60 connected to the first leveling cylinder 11 detects a pressure less than a preset pressure, it is determined that the left front wheel is not in contact with the ground. If the pressure sensor 60 connected to the second leveling cylinder 12 detects a pressure less than a preset pressure, it is determined that the right front wheel is not in contact with the ground. If the pressure sensor 60 connected to the third leveling cylinder 41 detects a pressure less than a preset pressure, it is determined that the left rear wheel is not in contact with the ground. If the pressure sensor 60 connected to the fourth leveling cylinder 42 detects a pressure less than a preset pressure, it is determined that the right rear wheel is not in contact with the ground.

[0117] In step S3000, if it is detected that the right front wheel is not in contact with the ground, then step S2100 is executed, that is, the electromagnetic control valve group 20 is controlled to enter the first leveling state, so as to drive the first leveling cylinder 11 to shorten and the second leveling cylinder 12 to extend, so that the right front wheel touches the ground.

[0118] If the left front wheel is not in contact with the ground, step S2200 is executed, that is, the electromagnetic control valve group 20 is controlled to enter the second leveling state, so as to drive the first leveling cylinder 11 to extend and the second leveling cylinder 12 to shorten, so that the left front wheel touches the ground.

[0119] If the right rear wheel is not in contact with the ground, step S2300 is executed, that is, the first solenoid valve 51 is controlled to enter the first reversing state, so as to drive the third leveling cylinder 41 to shorten and the fourth leveling cylinder 42 to extend, so that the right rear wheel touches the ground.

[0120] If the left rear wheel is not in contact with the ground, step S2400 is executed, that is, the first solenoid valve 51 is controlled to enter the second reversing state, so as to drive the third leveling cylinder 41 to extend and the fourth leveling cylinder 42 to shorten, so that the left rear wheel touches the ground.

[0121] Optionally, after the control solenoid valve group 20 or the first solenoid valve 51 changes its working state, the pressure on the corresponding leveling cylinder is continuously monitored. If the pressure value is not less than the preset pressure, it indicates that the wheel has touched the ground and the above actions stop.

[0122] Example 3

[0123] This embodiment provides an aerial work platform vehicle, which includes the hydraulic leveling device described in the previous embodiment. The vehicle also includes a chassis 100, a first axle 200, and a hydraulic system. The hydraulic system includes an oil tank, a supply pump, a supply line 31, and a return line 32. The oil tank stores hydraulic oil. The inlet end of the supply pump is connected to the oil tank, and the outlet end is connected to the supply line 31. The return line 32 is also connected to the oil tank. This hydraulic leveling device can automatically level the chassis 100 when the leveling requirements are not high, thus avoiding energy waste and frequent starting and stopping of the solenoid valves and cylinders. It is suitable for leveling the chassis 100 when the boom of the aerial work platform is retracted and the vehicle is in motion.

[0124] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A hydraulic leveling method, characterized in that, Applied to a hydraulic leveling device; the hydraulic leveling device, used for leveling the chassis (100) of an aerial work platform, includes: The first leveling cylinder (11) is located at one end on the chassis (100) and at the other end on the left end of the first axle (200) of the aerial work vehicle; The second leveling cylinder (12) is located at one end on the chassis (100) and at the other end on the right end of the first axle (200) of the aerial work vehicle; The first axle (200) pipeline is connected to the rod chamber of the first leveling cylinder (11) and the rodless chamber of the second leveling cylinder (12); The second axle (300) pipeline is connected to both the rodless chamber of the first leveling cylinder (11) and the rod chamber of the second leveling cylinder (12); The electromagnetic control valve assembly (20) is connected to the pipelines of the first axle (200), the pipelines of the second axle (300), the oil supply pipeline (31), and the oil return pipeline (32). The electromagnetic control valve assembly (20) has a connected state and a disconnected state. When the electromagnetic control valve assembly (20) is in the connected state, the pipelines of the first axle (200) and the second axle (300) are both connected to the oil supply pipeline (31). When the electromagnetic control valve assembly (20) is in the disconnected state, the pipelines of the first axle (200) and the second axle (300) are both connected to the oil return pipeline (32). The hydraulic leveling method includes: Obtain the boom angle of the aerial work vehicle; Compare the boom angle with the preset angle; If the boom angle is not greater than the preset angle, then the electromagnetic control valve group (20) is controlled to enter the connected state.

2. The hydraulic leveling method according to claim 1, characterized in that, The electromagnetic control valve assembly (20) also has a first leveling state and a second leveling state. When the electromagnetic control valve assembly (20) is in the first leveling state, the oil supply line (31) is connected to the first axle (200) line and the oil return line (32) is connected to the second axle (300) line. When the electromagnetic control valve assembly (20) is in the second leveling state, the oil supply line (31) is connected to the second axle (300) line and the oil return line (32) is connected to the first axle (200) line.

3. The hydraulic leveling method according to claim 2, characterized in that, Also includes: The third leveling cylinder (41) is located at one end on the chassis (100) and at the other end on the left end of the second axle (300) of the aerial work vehicle; The fourth leveling cylinder (42) is located at one end on the chassis (100) and at the other end on the right end of the second axle (300) of the aerial work vehicle; The third axle pipeline (43) is connected to the rod chamber of the third leveling cylinder (41) and the rodless chamber of the fourth leveling cylinder (42); The fourth axle pipeline (44) is connected to both the rodless chamber of the third leveling cylinder (41) and the rod chamber of the fourth leveling cylinder (42). The first solenoid valve (51) is connected to the third axle pipeline (43), the fourth axle pipeline (44), the oil supply pipeline (31), and the oil return pipeline (32). The first solenoid valve (51) has an initial state, a first reversing state, and a second reversing state. When the first solenoid valve (51) is in the initial state, the third axle pipeline (43) and the fourth axle pipeline (44) are both connected to the oil return pipeline (32). When the first solenoid valve (51) is in the first reversing state, the oil supply pipeline (31) is connected to the third axle pipeline (43), and the oil return pipeline (32) is connected to the fourth axle pipeline (44). When the first solenoid valve (51) is in the second reversing state, the oil supply pipeline (31) is connected to the fourth axle pipeline (44), and the oil return pipeline (32) is connected to the third axle pipeline (43).

4. The hydraulic leveling method according to claim 3, characterized in that, The first axle (200) is the front axle of the vehicle; the hydraulic leveling method includes: Obtain the boom angle of the aerial work vehicle; Compare the boom angle with the preset angle; If the boom angle is greater than the preset angle, then the following steps are performed: Detect the tilt state of the chassis (100); If the chassis (100) is detected to be tilted to the right front, the electromagnetic control valve group (20) is controlled to enter the first leveling state; If the chassis (100) is detected to be tilted to the left front, the electromagnetic control valve group (20) is controlled to enter the second leveling state.

5. The hydraulic leveling method according to claim 4, characterized in that, In the hydraulic leveling device, the second axle (300) is the rear axle of the vehicle; the hydraulic leveling method further includes: If the chassis (100) is detected to be tilted to the right rear, the first solenoid valve (51) is controlled to enter the first reversing state; If the chassis (100) is detected to be tilted to the left rear, the first solenoid valve (51) is controlled to enter the second reversing state.

6. The hydraulic leveling method according to claim 5, characterized in that, In the hydraulic leveling method, if the chassis (100) is detected to be tilted to the right, the electromagnetic control valve group (20) is controlled to enter the first leveling state, and the first electromagnetic valve (51) is controlled to enter the first reversing state. If the chassis (100) is detected to be tilted to the left, the electromagnetic control valve group (20) is controlled to enter the second leveling state, and the first electromagnetic valve (51) is controlled to enter the second reversing state.

7. The hydraulic leveling method according to claim 4, characterized in that, The hydraulic leveling device also includes a first tilt angle detection unit and a second tilt angle detection unit; In the hydraulic leveling method, detecting the tilt state of the chassis (100) includes: The tilt state of the chassis (100) in the left-right direction is detected by the first tilt angle detection unit, and the tilt state of the chassis (100) in the front-back direction is detected by the second tilt angle detection unit. If the first tilt detection unit detects that the chassis (100) is tilted to the right, and the second tilt detection unit detects that the chassis (100) is tilted forward, then it is determined that the chassis (100) is tilted to the right front. If the first tilt detection unit detects that the chassis (100) is tilted to the left, and the second tilt detection unit detects that the chassis (100) is tilted forward, then it is determined that the chassis (100) is tilted to the left front.

8. The hydraulic leveling method according to any one of claims 4-7, characterized in that, If the boom angle is greater than the preset angle, the wheel contact state is detected simultaneously when the tilt state of the chassis (100) is detected. If the right front wheel is not in contact with the ground, the electromagnetic control valve group (20) is controlled to enter the first leveling state; If the left front wheel is not in contact with the ground, the electromagnetic control valve group (20) is controlled to enter the second leveling state.

9. An aerial work platform vehicle, characterized in that, The aerial work platform includes a hydraulic leveling device used in the hydraulic leveling method as described in any one of claims 1-3. The aerial work platform also includes a chassis (100), a first axle (200), and a hydraulic system. The hydraulic system includes an oil tank, a supply pump, an oil supply line (31), and a return line (32). The oil tank is used to store hydraulic oil. The inlet end of the supply pump is connected to the oil tank, the outlet end is connected to the oil supply line (31), and the return line (32) is connected to the oil tank.

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