A scissor-type aerial work platform and its floating control system

Abstract

The present invention discloses a floating control system and a scissor-type aerial work platform, wherein the floating control system includes a floating oil cylinder, a balancing valve, a reversing valve and an oil tank; further includes: an accumulator, which is connected to the reversing valve and a pressure sensor; a third electromagnetic reversing valve, whose two ports are respectively connected to the oil return port and the oil outlet of the oil tank, and the other port is connected to the oil inlet of the reversing valve through a second one-way valve; an electric proportional relief valve, whose two ends are respectively connected to the oil return port and the oil outlet of the oil tank; a controller, which is connected to a motor, a pressure sensor, an electric proportional relief valve, a third electromagnetic reversing valve and an accumulator, and the motor provides driving force for the oil pump of the oil tank; when the pressure value is greater than or equal to the first preset pressure value, the control motor, the electric proportional relief valve, and the third electromagnetic reversing valve lose power; when the pressure value is less than or equal to the second preset pressure value, the control motor, the electric proportional relief valve, and the third electromagnetic reversing valve are powered on. The present application has a good operating experience.

Description

Technical Field

[0001] The present invention relates to the technical field of aerial work platforms, and more specifically, to a floating control system. In addition, the present invention also relates to a scissor-type aerial work platform comprising the floating control system. Background Art

[0002] In order to improve the walking stability, safety and passability of the vehicle under different road conditions, the existing off-road scissor-type aerial work platforms all adopt a structural method in which the front axle floats and the rear axle swings.

[0003] Normally, there is a floating cylinder on each side of the front axle. Under the joint action of the floating cylinders, the front axle can swing up and down around the swing axis, and the rear axle also adopts a swing structure.

[0004] When the working platform is raised (i.e. the scissors are unfolded) during walking, the rear axle swings with the ground and sends a signal to the controller through the travel switch associated with it in the structure to control the extension and retraction of the floating cylinder of the front axle, thereby realizing the active floating function during walking. In particular, for electric or hybrid off-road scissors, in order to ensure timely response of floating, an accumulator will be added to the hydraulic system to perform instantaneous oil replenishment during floating start.

[0005] However, when the working platform is not raised (i.e., the scissors are in the retracted state), the electric or hybrid off-road scissors in the prior art do not have a floating action, the ability of the vehicle to pass through is relatively weak, and the operating comfort is poor.

[0006] In summary, how to provide a scissor lift system with a strong sense of operating comfort is a problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0007] In view of this, an object of the present invention is to provide a floating control system, which can adjust the pressure state in the system to ensure the normal operation of the floating cylinder and provide a strong sense of comfort in operation.

[0008] Another object of the present invention is to provide a scissor-type aerial work platform including the above-mentioned floating control system.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] A floating control system comprises a floating oil cylinder, a balancing valve for delivering oil to a cavity of the floating oil cylinder, a reversing valve connected to the balancing valve and an oil tank; and further comprises:

[0011] an accumulator connected to the reversing valve and a pressure sensor for detecting a pressure value of the accumulator;

[0012] A third electromagnetic reversing valve, two ports of which are respectively connected to the oil return port and the oil outlet of the oil tank, and the other port is connected to the oil inlet of the reversing valve through a second one-way valve;

[0013] An electric proportional relief valve, two ends of which are respectively connected to the oil return port of the oil tank and the oil outlet of the oil tank;

[0014] A controller connected to the motor, the pressure sensor, the electric proportional relief valve, and the third electromagnetic reversing valve, wherein the motor provides driving force for the oil pump of the oil tank;

[0015] When the pressure value is greater than or equal to a first preset pressure value, the controller controls the motor, the electric proportional relief valve, and the third electromagnetic reversing valve to lose power; when the pressure value is less than or equal to a second preset pressure value, the controller controls the motor, the electric proportional relief valve, and the third electromagnetic reversing valve to gain power.

[0016] Preferably, the reversing valve comprises a first solenoid reversing valve and a second solenoid reversing valve;

[0017] The second ports of the first electromagnetic reversing valve and the second electromagnetic reversing valve are both connected to the oil return port of the oil tank, the third ports are both connected to the balance valve, and the first port is connected to the second port of the third electromagnetic reversing valve through the second one-way valve;

[0018] The first port of the third electromagnetic reversing valve is connected to the oil return port of the oil tank, and the third port of the third electromagnetic reversing valve is connected to the oil outlet of the oil tank and the oil inlet of the electric proportional relief valve.

[0019] Preferably, one end of the overflow valve is connected to the first ports of the first electromagnetic reversing valve and the second electromagnetic reversing valve, and the other end is connected to the second ports of the first electromagnetic reversing valve and the second electromagnetic reversing valve, and is connected to the oil return port of the oil tank;

[0020] The controller controls the set pressure value of the electric proportional relief valve so that the set pressure value of the electric proportional relief valve can be selected to be higher or lower than the set pressure value of the relief valve.

[0021] Preferably, the accumulator is connected to the third port of the accumulator-side reversing valve, the first port of the accumulator-side reversing valve is connected to the first port of the reversing valve, and the second port of the accumulator-side reversing valve is connected to the second port of the reversing valve.

[0022] Preferably, a first one-way valve is provided on the connecting pipeline between the electric proportional relief valve and the oil outlet of the oil tank, and the first one-way valve is on the main pipeline of the oil outlet of the oil tank;

[0023] The inlet of the first one-way valve is connected to the oil outlet of the oil tank, and the outlet of the first one-way valve is connected to the inlet of the electric proportional relief valve.

[0024] Preferably, the third port of the third electromagnetic reversing valve is connected to the outlet of the first one-way valve.

[0025] Preferably, the balancing valve comprises: a first two-way balancing valve and a second two-way balancing valve;

[0026] The first two-way balancing valve and the second two-way balancing valve each have a port connected to the third port of the first electromagnetic reversing valve, and the first two-way balancing valve and the second two-way balancing valve each have another port connected to the third port of the second electromagnetic reversing valve.

[0027] Preferably, the floating cylinder comprises a first floating cylinder and a second floating cylinder;

[0028] The third port of the first two-way balancing valve is connected to the rodless chamber of the first floating cylinder, and the fourth port of the first two-way balancing valve is connected to the rod chamber of the first floating cylinder;

[0029] The third port of the second two-way balancing valve is connected to the rodless chamber of the second floating cylinder, and the fourth port of the second two-way balancing valve is connected to the rod chamber of the second floating cylinder.

[0030] Preferably, the controller is connected to a handle.

[0031] A scissor-type aerial work platform comprises the floating control system described in any one of the above items.

[0032] In the floating control system provided by the present application, a pressure sensor for detecting oil pressure is provided to obtain the system pressure. When the system pressure is higher than a higher value, the controller is used to control the on and off of the motor, the electric proportional relief valve and the third electromagnetic reversing valve in the system so as to maintain a certain pressure in the system, so that the oil pressure can be slowly reduced while providing a certain amount of hydraulic oil to the floating cylinder. In this process, the system operating performance can be maintained and has a good operating experience. When the system pressure is reduced to a lower value, the above structure is controlled to be powered, thereby achieving oil supply and pressure increase. When the system pressure of the floating control system provided by the present application is in different states, different control methods can be adopted, and the hydraulic oil of the system accumulator can be used to achieve energy supply, thereby improving the operating comfort, saving energy and operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0034] Figure 1 A schematic diagram of a hydraulic system of a floating control system provided in this application.

[0035] Figure 1 , the reference numerals include:

[0036] Oil tank 1, motor 2, oil pump 3, handle 5, controller 6, pressure sensor 8, accumulator 9, relief valve 17, electric proportional relief valve 19;

[0037] A first one-way valve 4, a second one-way valve 16;

[0038] A first electromagnetic reversing valve 10, a second electromagnetic reversing valve 15, a third electromagnetic reversing valve 18, and an accumulator-side reversing valve 7;

[0039] A first two-way balancing valve 11, a second two-way balancing valve 14;

[0040] A first floating cylinder 12 and a second floating cylinder 13. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The core of the present invention is to provide a floating control system, which can adjust the pressure state in the system to ensure the normal operation of the floating oil cylinder and provide a strong sense of operating comfort.

[0043] Another core of the present invention is to provide a scissor-type aerial work platform including the above-mentioned floating control system.

[0044] Please refer to Figure 1 , Figure 1Schematic diagram of a hydraulic system of a floating control system provided by the present application. The present application provides a floating control system for floating compensation of a scissor-type aerial work platform, including a floating cylinder, a balancing valve for supplying oil to the cavity of the floating cylinder, a reversing valve connected to the balancing valve, and an oil tank 1; it also includes an accumulator 9, a pressure sensor 8, a third electromagnetic reversing valve 18, an electric proportional relief valve 19, and a controller 6.

[0045] The first port of the reversing valve is connected to the oil return port of the oil tank 1 , the second port of the reversing valve is connected to the floating cylinder, and the third port of the reversing valve is connected to the oil outlet of the oil tank 1 through the second one-way valve 16 .

[0046] The accumulator 9 is connected to a reversing valve and a pressure sensor 8 for detecting a pressure value of the accumulator 9 .

[0047] Two ports of the third electromagnetic reversing valve 18 are connected to the oil return port and the oil outlet of the oil tank 1 respectively, and the other port is connected to the oil inlet of the reversing valve through the second one-way valve 16;

[0048] The two ports of the electric proportional relief valve 19 are connected to the oil return port of the oil tank 1 and the oil outlet of the oil tank 1 respectively.

[0049] The controller 6 is connected to the motor 2 , the pressure sensor 8 , the electric proportional relief valve 19 , and the third electromagnetic reversing valve 18 . The motor 2 provides driving force for the oil pump 3 of the oil tank 1 .

[0050] During the control process, when the pressure value is greater than or equal to the first preset pressure value, the control motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 lose power; when the pressure value is less than or equal to the second preset pressure value, the control motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 are powered. The first preset pressure value is greater than the second preset pressure value.

[0051] In the floating control system provided in the present application, the oil pump 3 is driven by the motor 2 to transport the hydraulic oil in the oil tank 1 to the system. The first port of the reversing valve is connected to the oil outlet of the oil tank 1, that is, the oil outlet of the oil pump 3. A first one-way valve 4 can be set on the oil outlet pipeline of the oil pump 3 to prevent the backflow of oil when the oil pump 3 stops.

[0052] The pressure sensor 8 monitors the pressure of the accumulator 9 to obtain a system pressure value.

[0053] When the system is filled with oil to the set pressure value, the controller 6 receives the signal from the pressure sensor 8 and performs a power-off operation, specifically including de-energizing the control motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 to stop supplying oil to the system.

[0054] Since the one-way valve can provide a pressure-maintaining effect for a period of time, the hydraulic oil in this part of the system can provide hydraulic oil to the balancing valve, floating cylinder, etc. through the reversing valve to ensure the normal operation of the floating cylinder. It can be seen that the motor 2 does not need to be running at this time and can also achieve the above work, thereby achieving an energy-saving and noise-free working state.

[0055] After a certain period of time, when the pressure value of the accumulator 9 detected by the pressure sensor 8 continues to decrease and reaches a lower value, the controller 6 receives the detection signal of the pressure sensor 8, and the controller 6 controls the motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 to be energized, so that the motor 2 drives the oil pump 3 to rotate and pump hydraulic oil. The hydraulic oil enters the accumulator 9 through the hydraulic circuit and enters the floating cylinder through the reversing valve. In this process, the pressure in the hydraulic system continues to increase, and the pressure value detected by the pressure sensor 8 increases, thereby returning to the state where the system is filled with oil to the set pressure value.

[0056] In the floating control system provided in the present application, a pressure sensor 8 for detecting oil pressure is arranged in the hydraulic system to obtain the system pressure. When the system pressure is higher than a higher value, the controller 6 is used to control the motor 2, the electric proportional relief valve 19 and the third electromagnetic reversing valve 18 in the system to lose power so as to maintain a certain pressure in the system, so that the oil pressure can be slowly reduced while a certain amount of hydraulic oil can be provided to the floating cylinder. In this process, the system operating performance can be maintained and the operating experience is better. When the hydraulic oil is reduced to a lower value, the above-mentioned structure is controlled to be energized to achieve oil supply and pressure increase.

[0057] The floating control system provided in the present application can adopt different control methods when the system pressure is in different states, and utilize the hydraulic oil of the system accumulator 9 to realize energy supply, thereby improving the operating comfort, saving energy and achieving efficient operation.

[0058] In the present application, the controller 6 is connected to the handle 5 , and the output of the controller 6 is controlled by the handle 5 .

[0059] In a specific embodiment, the reversing valve includes a first solenoid reversing valve 10 and a second solenoid reversing valve 15;

[0060] The second ports of the first solenoid reversing valve 10 and the second solenoid reversing valve 15 are both connected to the oil return port of the oil tank 1, the third ports of the first solenoid reversing valve 10 and the second solenoid reversing valve 15 are both connected to the balance valve, and the first ports of the first solenoid reversing valve 10 and the second solenoid reversing valve 15 are connected to the second port of the third solenoid reversing valve 18 through the second one-way valve 16;

[0061] The first port of the third electromagnetic reversing valve 18 is connected to the oil return port of the oil tank 1 , and the third port of the third electromagnetic reversing valve 18 is connected to the oil outlet of the oil tank 1 and the oil inlet of the electric proportional relief valve 19 .

[0062] In this embodiment, the first electromagnetic reversing valve 10 and the second electromagnetic reversing valve 15 are respectively connected to the balancing valve because the number of balancing valves is usually two, which are used for the settings of two floating cylinders respectively.

[0063] On the basis of the above embodiment, a relief valve 17 is provided in the floating control system, one end of the relief valve 17 is connected to the first port of the first solenoid reversing valve 10 and the second solenoid reversing valve 15, and the other end is connected to the second port of the first solenoid reversing valve 10 and the second solenoid reversing valve 15, and is connected to the oil return port of the oil tank 1;

[0064] The controller 6 controls the set pressure value of the electric proportional relief valve 19 so that the set pressure value of the electric proportional relief valve 19 can be selected to be higher or lower than the set pressure value of the relief valve 17 .

[0065] Please refer to Figure 1 , wherein the two ports of the electric proportional relief valve 19 are respectively connected to the outlet of the first one-way valve 4 and the oil return port of the oil tank 1, the relief valve 17, the first solenoid reversing valve 10 and the second solenoid reversing valve 15 are arranged in parallel, and the parallel circuit is arranged in series with the third solenoid reversing valve 18, that is, after passing through the first one-way valve 4, the hydraulic oil can pass through the third solenoid reversing valve 18 and then enter the above-mentioned parallel structure.

[0066] The set pressures of the electric proportional relief valve 19 and the relief valve 17 are different, and the set pressure value of the electric proportional relief valve 19 can be adjusted by a controller to achieve different system control pressures.

[0067] For example, when the workbench is not raised, the controller 6 controls the electric proportional relief valve 19 to set a low pressure value lower than the pressure limit of the relief valve 17. The pressure of the hydraulic system depends on the set value of the electric proportional relief valve 19. The set value of this pressure needs to be able to fully open the two balance valves and ensure that the piston rod of the floating cylinder can be extended so that the tire touches the ground.

[0068] When the workbench is in the elevated state, the controller 6 controls the electric proportional relief valve 19 to set a high pressure value higher than the pressure limit of the relief valve 17. The hydraulic system pressure depends on the set value of the relief valve 17. This pressure value must be able to fully open the balance valve and ensure that the piston rod of the floating cylinder is extended to level the chassis.

[0069] In the embodiment provided in the present application, the electric proportional relief valve 19 is a variable valve body that can control the relief pressure, which is connected to the controller 6 and is used to adjust different relief pressures of different control modes in the system under different working conditions.

[0070] Based on the above embodiment, the accumulator 9 is connected to the third port of the accumulator-side reversing valve 7, the first port of the accumulator-side reversing valve 7 is connected to the first port of the reversing valve, and the second port of the accumulator-side reversing valve 7 is connected to the second port of the reversing valve.

[0071] It should be noted that, in the present application, the first electromagnetic reversing valve 10 and the second electromagnetic reversing valve 15 are both two-position three-way electromagnetic reversing valves, and the accumulator-side reversing valve 7 is a two-position three-way electromagnetic reversing valve.

[0072] Both ports of the accumulator-side reversing valve 7 are connected to the first solenoid reversing valve 10 and the second solenoid reversing valve 15. The accumulator-side reversing valve 7 is used to control the inflow and outflow of hydraulic oil in the hydraulic circuit so as to control the flow of hydraulic oil between the accumulator and the reversing valve.

[0073] In a specific embodiment, a first check valve 4 is provided on the connecting pipeline between the electric proportional relief valve 19 and the oil outlet of the oil tank 1, and the first check valve is on the main pipeline of the oil outlet of the oil tank 1;

[0074] The inlet of the first one-way valve 4 is connected to the oil outlet of the oil tank 1 , and the outlet of the first one-way valve 4 is connected to the inlet of the electric proportional relief valve 19 .

[0075] The function of the first one-way valve 4 is to prevent oil from returning to the oil pump 3, wherein the third port of the third electromagnetic reversing valve 18 is connected to the outlet connection of the first one-way valve 4, and when the third electromagnetic reversing valve 18 is in the disconnected state, the instability of the oil flow is avoided.

[0076] Based on any one of the above embodiments, the balancing valve includes: a first two-way balancing valve 11 and a second two-way balancing valve 14;

[0077] The first two-way balancing valve 11 and the second two-way balancing valve 14 each have a port connected to the third port of the first electromagnetic reversing valve 10 , and the first two-way balancing valve 11 and the second two-way balancing valve 14 each have another port connected to the third port of the second electromagnetic reversing valve 15 .

[0078] In addition, the floating cylinder includes a first floating cylinder 12 and a second floating cylinder 13;

[0079] The third port of the first two-way balancing valve 11 is connected to the rodless chamber of the first floating oil cylinder 12, and the fourth port of the first two-way balancing valve 11 is connected to the rod chamber of the first floating oil cylinder 12;

[0080] The third port of the second two-way balancing valve 14 is connected to the rodless chamber of the second floating cylinder 13 , and the fourth port of the second two-way balancing valve 14 is connected to the rod chamber of the second floating cylinder 3 .

[0081] In a specific embodiment provided by the present application, the floating control system includes an oil tank 1, a motor 2, an oil pump 3, a controller 6, an accumulator side reversing valve 7, a pressure sensor 8, an accumulator 9, a relief valve 17, and an electric proportional relief valve 19; wherein the valve body structure provided includes:

[0082] A first one-way valve 4, a second one-way valve 16;

[0083] A first electromagnetic reversing valve 10, a second electromagnetic reversing valve 15, a third electromagnetic reversing valve 18, and an accumulator-side reversing valve 7;

[0084] A first two-way balancing valve 11, a second two-way balancing valve 14;

[0085] The first floating cylinder 12 and the second floating cylinder 13 .

[0086] In the present application, the electric proportional relief valve 19 can be a positive proportional relief valve or a negative proportional relief valve, and the types of each electromagnetic reversing valve can also be adjusted according to the use requirements. In addition, the relief valve 17 can be a direct-acting relief valve, a pilot relief valve or a proportional relief valve.

[0087] Please refer to Figure 1 The oil outlet of the oil pump 3 (or the oil outlet of the oil tank 1) is connected to the inlet of the first one-way valve 4, and the outlet of the first one-way valve 4 is connected to the oil inlet of the electric proportional relief valve 19 and the third port of the third electromagnetic reversing valve 18 ( Figure 1 ③ in the middle, i.e. the oil inlet) connection;

[0088] The oil tank 1 is connected to the oil outlet of the electric proportional relief valve 19 and the oil outlet of the relief valve 17, and is also connected to the second port of the first electromagnetic reversing valve 10, the second port of the second electromagnetic reversing valve 15, the first port of the third electromagnetic reversing valve 18 and the second port of the accumulator side reversing valve 7 ( Figure 1 ②) to realize oil return to oil tank 1.

[0089] The second port ( Figure 1 ②, i.e., the oil outlet) is connected to the oil inlet of the second one-way valve 16, and the oil outlet of the second one-way valve 16 is connected to the first port of the first electromagnetic reversing valve 10, the first port of the second electromagnetic reversing valve 15, and the first port of the accumulator side reversing valve 7.

[0090] The third port of the first electromagnetic reversing valve 10 is connected to the second port of the first two-way balancing valve 11 and the first port of the second two-way balancing valve 14;

[0091] The third port of the second electromagnetic reversing valve 15 is connected to the first port of the first two-way balancing valve 11 and the second port of the second two-way balancing valve 14;

[0092] The third port and the fourth port of the first two-way balancing valve 11 are connected to the rodless chamber and the rod chamber of the first floating cylinder 12 respectively. The third port and the fourth port of the second two-way balancing valve 14 are connected to the rodless chamber and the rod chamber of the second floating cylinder 13 respectively.

[0093] The third port of the accumulator-side reversing valve 7 is connected to the accumulator 9 and the pressure sensor 8 .

[0094] Both ends of the relief valve 17 are connected to the first port and the second port of the first electromagnetic reversing valve 10 respectively, or are connected to other positions equivalent to these two positions.

[0095] The controller 6 of the present application is connected to the motor 2 , the pressure sensor 8 , the accumulator 9 , the electric proportional relief valve 19 , the first electromagnetic reversing valve 10 , the second electromagnetic reversing valve 15 , the third electromagnetic reversing valve 18 , and the accumulator-side reversing valve 7 .

[0096] When the scissors of the working platform are in the retracted state, push the handle 5 to perform the walking operation.

[0097] The controller 6 controls the motor 2, the electric proportional relief valve 19, the first electromagnetic reversing valve 10, the second electromagnetic reversing valve 15, the third electromagnetic reversing valve 18, and the accumulator side reversing valve 7 to be connected and powered, and the pressure sensor 8 feeds back the monitoring signal to the controller. After the motor 2 is powered, it drives the oil pump 3 to provide hydraulic oil, and the hydraulic oil enters the accumulator 9, and the rod chamber and rodless chamber of the first floating oil cylinder 12 and the second floating oil cylinder 13 through the above-mentioned hydraulic circuit. Since the rod chamber and the rodless chamber are both subjected to the pressure transmission of the valve body, the pressure of the two is the same, and the effective area of ​​the rodless chamber is larger than the effective area of ​​the rod chamber, and the piston rods of the first floating oil cylinder 12 and the second floating oil cylinder 13 can be extended outward. At this time, the controller 6 controls the electric proportional relief valve 19 to set a pressure value lower than the limit value of the relief valve 17, and the system pressure depends on the pressure value of the electric proportional relief valve 19. This pressure value needs to be able to fully open the first two-way balancing valve 11 and the second two-way balancing valve 14, and ensure that the piston rods of the first floating oil cylinder 12 and the second floating oil cylinder 13 are extended to make the tire touch the ground in real time.

[0098] In the above state, the pressure sensor 8 on the hydraulic circuit detects the pressure value in the accumulator 9 in real time and feeds it back to the controller 6. When it is detected that the filling pressure reaches the set first pressure value, the controller 6 controls the motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 to lose power, and the system stops supplying oil to the balance valve. At this time, the hydraulic oil in the accumulator 9 can be stored in the system circuit for a long time under the action of the second one-way valve 16, which can ensure the normal operation of the first floating oil cylinder 12 and the second floating oil cylinder 13. Therefore, in the current state, the motor 2 will not run, and some electromagnetic valves on the floating circuit do not need to be powered, which is energy-saving and noise-free. After a period of time, the system pressure drops. When the pressure sensor 8 detects that the pressure of the accumulator 9 is lower than the second preset value, the controller 6 will control the motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 to be energized. After the motor 2 is energized, it drives the oil pump 3 to start pumping hydraulic oil. The hydraulic oil enters the hydraulic circuit and enters the rod chamber and the rodless chamber of the accumulator 9, the first floating cylinder 12 and the second floating cylinder 13. This reciprocating process is used to realize the floating action when the working platform is not raised (that is, the scissors are in a retracted state).

[0099] The above control method can enable the electric or hybrid off-road scissors to move and float at the same time when the working platform is retracted. The adjustment method realized by this structure can improve the vehicle's passing ability under different road conditions, enhance operating comfort, avoid the occurrence of loud noise, and achieve energy-saving operation.

[0100] Similarly, when the working platform is raised (i.e., the scissors are in the unfolded state), the handle 5 is pushed to perform the walking action, and the controller 6 controls the motor 2, the electric proportional relief valve 19, the third electromagnetic reversing valve 18, and the accumulator side reversing valve 7 to be energized. The motor 2 controls the oil pump 3 to supply oil, and the hydraulic oil enters the accumulator 9 through the hydraulic circuit. At this time, the electric proportional relief valve 19 sets a high pressure value higher than the relief valve 17. The system pressure depends on the set value of the relief valve 17. This pressure value needs to be able to completely open the first two-way balance valve 11, the second two-way balance valve 14, and ensure that the piston rods of the first floating oil cylinder 12 and the second floating oil cylinder 13 are extended to level the chassis.

[0101] In the above state, when it is detected that the filling oil pressure reaches the set first pressure value, the controller 6 controls the motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 to lose power and stop supplying oil. The hydraulic oil in the accumulator 9 can be stored in the circuit for a long time under the action of the second one-way valve 16. This part of the hydraulic oil can ensure the oil replenishment at the moment of starting the floating cylinder and improve the action response of the floating cylinder. Therefore, under this working condition, the motor 2 does not operate, and some electromagnetic valves on the floating circuit do not need to be powered, which is energy-saving and noise-free. When the pressure sensor 8 detects that the pressure of the accumulator 9 is lower than a certain value, the controller 6 controls the motor 2, the electric proportional relief valve 19, and the third electromagnetic reversing valve 18 to be powered, and the motor 2 controls the oil pump 3 to pump the pressure oil, and the hydraulic oil enters the accumulator 9 through the hydraulic circuit to realize the floating action when the working platform is raised (that is, the scissors are in the unfolded state).

[0102] In addition to the main hydraulic structure and connection relationship of the floating control system provided in the above-mentioned embodiments, the present invention also provides a scissor-type aerial work platform including the above-mentioned floating control system. The scissor-type aerial work platform adopts the above-mentioned floating control system to achieve relatively smooth operation and good operating effect. Please refer to the prior art for the structure of other parts, which will not be repeated in this article.

[0103] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0104] The floating control system and the scissor-type aerial work platform provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A floating control system, comprising a floating oil cylinder, a balancing valve for supplying oil to a cavity of the floating oil cylinder, a reversing valve connected to the balancing valve, and an oil tank (1); characterized in that: Also includes: An accumulator (9) connected to the reversing valve and a pressure sensor (8) for detecting a pressure value of the accumulator (9); A third electromagnetic reversing valve (18), two ports of which are respectively connected to the oil return port and the oil outlet of the oil tank (1), and the other port is connected to the oil inlet of the reversing valve via a second one-way valve (16); An electric proportional relief valve (19), two ends of which are respectively connected to the oil return port of the oil tank (1) and the oil outlet of the oil tank (1); a controller (6) connected to the motor (2), the pressure sensor (8), the electric proportional relief valve (19), and the third electromagnetic reversing valve (18), wherein the motor (2) provides driving force for the oil pump (3) of the oil tank (1); When the pressure value is greater than or equal to a first preset pressure value, the controller (6) controls the motor (2), the electric proportional relief valve (19), and the third electromagnetic reversing valve (18) to lose power; when the pressure value is less than or equal to a second preset pressure value, the controller (6) controls the motor (2), the electric proportional relief valve (19), and the third electromagnetic reversing valve (18) to gain power; The reversing valve comprises a first electromagnetic reversing valve (10) and a second electromagnetic reversing valve (15); The second ports of the first electromagnetic reversing valve (10) and the second electromagnetic reversing valve (15) are both connected to the oil return port of the oil tank (1), the third ports are both connected to the balancing valve, and the first port is connected to the second port of the third electromagnetic reversing valve (18) via the second one-way valve (16); The first port of the third electromagnetic reversing valve (18) is connected to the oil return port of the oil tank (1), and the third port of the third electromagnetic reversing valve (18) is connected to the oil outlet of the oil tank (1) and the oil inlet of the electric proportional relief valve (19); One end of the overflow valve (17) is connected to the first ports of the first electromagnetic reversing valve (10) and the second electromagnetic reversing valve (15), and the other end is connected to the second ports of the first electromagnetic reversing valve (10) and the second electromagnetic reversing valve (15), and is also connected to the oil return port of the oil tank (1); The controller (6) controls the set pressure value of the electric proportional relief valve (19) so that the set pressure value of the electric proportional relief valve (19) is higher or lower than the set pressure value of the relief valve (17); A first one-way valve (4) is provided on the connecting pipeline between the electric proportional relief valve (19) and the oil outlet of the oil tank (1), and the first one-way valve is on the main pipeline of the oil outlet of the oil tank (1); The inlet of the first one-way valve (4) is connected to the oil outlet of the oil tank (1), and the outlet of the first one-way valve (4) is connected to the inlet of the electric proportional relief valve (19).

2. The floating control system according to claim 1, characterized in that: The accumulator (9) is connected to the third port of the accumulator-side reversing valve (7), the first port of the accumulator-side reversing valve (7) is connected to the first port of the reversing valve, and the second port of the accumulator-side reversing valve (7) is connected to the second port of the reversing valve.

3. The floating control system according to claim 1, characterized in that: The third port of the third electromagnetic reversing valve (18) is connected to the outlet of the first one-way valve (4).

4. The floating control system according to claim 2 or 3, characterized in that: The balancing valve comprises: a first two-way balancing valve (11) and a second two-way balancing valve (14); The first two-way balancing valve (11) and the second two-way balancing valve (14) each have a port connected to the third port of the first electromagnetic reversing valve (10), and the first two-way balancing valve (11) and the second two-way balancing valve (14) each have another port connected to the third port of the second electromagnetic reversing valve (15).

5. The floating control system according to claim 4, characterized in that: The floating oil cylinder comprises a first floating oil cylinder (12) and a second floating oil cylinder (13); The third port of the first two-way balancing valve (11) is connected to the rodless chamber of the first floating oil cylinder (12), and the fourth port of the first two-way balancing valve (11) is connected to the rod chamber of the first floating oil cylinder (12); The third port of the second two-way balancing valve (14) is connected to the rodless chamber of the second floating cylinder (13), and the fourth port of the second two-way balancing valve (14) is connected to the rod chamber of the second floating cylinder (13).

6. The floating control system according to claim 4, characterized in that: The controller (6) is connected to the handle (5).

7. A scissor-type aerial work platform, characterized in that: A floating control system comprising any one of claims 1 to 6.

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