Energy-saving hydraulic control system for overhead working truck

Abstract

The utility model relates to an energy-saving hydraulic control system for an overhead working truck, and belongs to the field of overhead working trucks. The hydraulic system comprises a main pump, an engine, an overflow valve, a first electromagnetic valve, a lower vehicle proportional valve, a low-precision proportional three-way flow valve, a one-way valve, a high-precision proportional valve, a second electromagnetic valve, a third electromagnetic valve, an oil tank, a first oil inlet pipe, a first oil outlet pipe, a second oil outlet pipe, a second oil inlet pipe and a third oil inlet pipe. The device is structurally characterized in that the two ends of the first oil inlet pipe are connected with the first electromagnetic valve and the oil tank respectively, the two ends of the first oil outlet pipe are connected with the one-way valve and the oil tank respectively, and the two ends of the second oil outlet pipe are connected with the one-way valve and the high-precision proportional valve respectively; the two ends of the second oil inlet pipe are connected with the high-precision proportional valve and the first electromagnetic valve respectively, the two ends of the third oil inlet pipe are connected with the first electromagnetic valve and the lower vehicle proportional valve respectively, the main pump is connected with the engine, and the main pump and the overflow valve are both arranged on the first oil inlet pipe.

Description

Technical Field

[0001] This utility model relates to an energy-saving hydraulic control system for aerial work platforms, belonging to the field of aerial work platforms. Background Technology

[0002] Some aerial work platforms place the proportional valve assembly before the central rotating body to allow excess hydraulic oil to flow back to the tank more quickly, thus bringing the valve assembly closer to the main pump and oil tank. This results in two oil pipes passing through the central rotating body for each action, leading to too many channels in the central rotating body, making it difficult to manufacture. Furthermore, the numerous oil pipes passing through the central rotating body make pipe laying more difficult. Placing the proportional valve assembly after the central rotating body reduces the number of channels and connecting pipes in the central rotating body, but the valve assembly is farther from the main pump and oil tank, increasing the hydraulic oil return distance and thus increasing energy loss.

[0003] Some actions of aerial work platforms require high-precision control, while others do not. Using high-precision proportional valves for all actions would be costly. Some aerial work platform chassis have large engine displacements with ample power output, which can lead to energy waste. After a conventional vehicle completes an action and is left idle for a period of time, the hydraulic oil will flow back to the tank. At this time, some pipelines will be without hydraulic oil. When the actuator and the control valve group are far apart, there will be action delays and energy loss due to the recharging of hydraulic oil. Utility Model Content

[0004] The purpose of this utility model is to overcome the above-mentioned shortcomings in the existing technology and to provide a hydraulic control system for an energy-saving aerial work platform with a reasonable structural design.

[0005] The technical solution adopted by this utility model to solve the above problems is as follows: The energy-saving aerial work platform hydraulic control system includes a main pump, engine, overflow valve, No. 1 solenoid valve, lowering proportional valve, low-precision proportional three-way flow valve, check valve, high-precision proportional valve, No. 2 solenoid valve, No. 3 solenoid valve, oil tank, No. 1 oil inlet pipe, No. 1 oil outlet pipe, No. 2 oil outlet pipe, No. 2 oil inlet pipe, and No. 3 oil inlet pipe. Its structural feature is that both ends of the No. 1 oil inlet pipe are respectively connected to the No. 1 solenoid valve and the oil tank, and the No. 1 oil outlet pipe… Both ends of the No. 2 oil outlet pipe are connected to the check valve and the oil tank respectively. Both ends of the No. 2 oil outlet pipe are connected to the check valve and the high-precision proportional valve respectively. Both ends of the No. 2 oil inlet pipe are connected to the high-precision proportional valve and the No. 1 solenoid valve respectively. Both ends of the No. 3 oil inlet pipe are connected to the No. 1 solenoid valve and the off-vehicle proportional valve respectively. The main pump is connected to the engine. The main pump and the overflow valve are both installed on the No. 1 oil inlet pipe. The low-precision proportional three-way flow valve is installed on the No. 2 oil inlet pipe. The No. 2 solenoid valve and the No. 3 solenoid valve are both connected to the high-precision proportional valve.

[0006] Furthermore, the first solenoid valve is equipped with a first electromagnet and a second electromagnet.

[0007] Furthermore, the second solenoid valve is connected to the first actuator.

[0008] Furthermore, it also includes a flow distribution valve, which is connected to a spring and to a first channel and a second channel. The first channel is connected to a second solenoid valve and a third solenoid valve. The high-precision proportional valve includes multiple proportional valve groups. The second channel is connected to multiple proportional valve groups, and the multiple proportional valve groups are connected to the second actuator through an actuation pipeline.

[0009] Furthermore, the flow distribution valve is connected to the first throttling orifice, the second throttling orifice, and the third throttling orifice.

[0010] Furthermore, the low-precision proportional three-way flow valve and the high-precision proportional valve constitute the upper vehicle proportional valve. The upper vehicle proportional valve is used to control the movement of the upper part of the vehicle, and the lower vehicle proportional valve is used to control the movement of the lower part of the vehicle.

[0011] Furthermore, the high-precision proportional valve is located after the central rotating body, while the low-precision proportional three-way flow valve is located before the central rotating body.

[0012] Furthermore, the high-precision proportional valve is located after the central rotating body, while the low-precision proportional three-way flow valve is located before the central rotating body.

[0013] Compared with the prior art, the present invention has the following advantages: The hydraulic control system of this energy-saving aerial work vehicle reduces the hydraulic oil return distance by setting a low-precision proportional three-way flow valve before the central rotating body and a high-precision proportional valve and flow distribution valve after the central rotating body, and can also use high and low precision control for different actions.

[0014] By coordinating different engine speeds with different actions, energy loss can be better controlled and costs can be effectively saved. This hydraulic control system uses a constant power variable pump, which can make the engine power margin smaller. Even in some extreme cases where the engine cannot run, the engine stalls by reducing the pump displacement. A one-way valve is added to the oil outlet pipe to lock the hydraulic oil in the oil outlet pipe, which avoids action delay and reduces energy loss caused by repeated filling of the pipe. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the hydraulic control system of the energy-saving aerial work vehicle according to an embodiment of the present invention.

[0016] In the diagram: 1. Main pump; 2. Engine; 3. Overflow valve; 4. Solenoid valve 1; 5. Electromagnet 1; 6. Electromagnet 2; 7. Lowering proportional valve; 8. Low-precision proportional three-way flow valve; 9. Check valve; 10. Flow distribution valve; 11. Pressure point 1; 12. Throttling orifice 1; 13. Channel 1; 14. Channel 2; 15. Pressure point 2; 16. Spring; 17. Throttling orifice 2; 18. Central rotating body; 19. High-precision proportional valve; 20. Solenoid valve 2; 21. Actuator 1; 22. Solenoid valve 3; 23. Throttling orifice 3; 24. Oil tank; 25. Inlet pipe 1; 26. Outlet pipe 1; 27. Inlet pipe 2; 28. Inlet pipe 3; 29. ​​Actuator 2; 30. Proportional valve assembly; 31. Actuating oil pipe; 32. Outlet pipe 2. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0018] Example

[0019] See Figure 1 As shown in the accompanying drawings, the structures, proportions, sizes, etc., depicted in this specification are merely for illustrative purposes to aid those skilled in the art and to provide a clear understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the use of terms such as "upper," "lower," "left," "right," "middle," and "one" in this specification is solely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0020] The energy-saving aerial work platform hydraulic control system in this embodiment includes a main pump 1, an engine 2, an overflow valve 3, a first solenoid valve 4, a lowering proportional valve 7, a low-precision proportional three-way flow valve 8, a check valve 9, a flow distribution valve 10, a high-precision proportional valve 19, a second solenoid valve 20, a third solenoid valve 22, an oil tank 24, a first oil inlet pipe 25, a first oil outlet pipe 26, a second oil outlet pipe 32, a second oil inlet pipe 27, and a third oil inlet pipe 28.

[0021] In this embodiment, the two ends of the No. 1 oil inlet pipe 25 are connected to the No. 1 solenoid valve 4 and the oil tank 24, respectively; the two ends of the No. 1 oil outlet pipe 26 are connected to the one-way valve 9 and the oil tank 24, respectively; the two ends of the No. 2 oil outlet pipe 32 are connected to the one-way valve 9 and the high-precision proportional valve 19, respectively; the two ends of the No. 2 oil inlet pipe 27 are connected to the high-precision proportional valve 19 and the No. 1 solenoid valve 4, respectively; the two ends of the No. 3 oil inlet pipe 28 are connected to the No. 1 solenoid valve 4 and the lowering proportional valve 7, respectively; the main pump 1 is connected to the engine 2; the main pump 1 and the overflow valve 3 are both installed on the No. 1 oil inlet pipe 25; and the No. 1 solenoid valve 4 is equipped with a No. 1 electromagnet 5 and... Electromagnet 6 (No. 2), low-precision proportional three-way flow valve 8 (No. 2) is installed on oil inlet pipe 27 (No. 2), solenoid valve 20 (No. 2) and solenoid valve 22 (No. 3) are both connected to high-precision proportional valve 19 (No. 19), flow distribution valve 10 is connected to spring 16 (No. 1) and flow distribution valve 10 is connected to channel 13 (No. 1) and channel 14 (No. 2), channel 13 (No. 1) is connected to solenoid valve 20 (No. 2) and solenoid valve 22 (No. 3), channel 14 (No. 2) is connected to multiple proportional valve groups 30 of high-precision proportional valve 19 (No. 19), solenoid valve 20 (No. 2) is connected to actuator 21 (No. 1), and multiple proportional valve groups 30 are connected to actuator 29 (No. 2) through actuation pipeline 31 (No. 2).

[0022] In this embodiment, the flow distribution valve 10 is connected to the spring 16, the flow distribution valve 10 is connected to the first channel 13 and the second channel 14, the first channel 13 is connected to the second solenoid valve 20 and the third solenoid valve 22, the second channel 14 is connected to each valve group of the high-precision proportional valve 19, and the flow distribution valve 10 is connected to the first throttling orifice 12, the second throttling orifice 17 and the third throttling orifice 23.

[0023] In this embodiment, the low-precision proportional three-way flow valve 8 and the high-precision proportional valve 19 constitute the upper vehicle proportional valve. The upper vehicle proportional valve is used to control the upper part of the vehicle to perform actions (such as bucket, boom, etc.), and the lower vehicle proportional valve 7 is used to control the lower part of the vehicle to perform actions (such as hydraulic outriggers, etc.). The high-precision proportional valve 19 is after the central rotating body 18, and the low-precision proportional three-way flow valve 8 is before the central rotating body 18.

[0024] The control method of the hydraulic control system of the energy-saving aerial work vehicle in this embodiment is as follows: the engine 2 drives the main pump 1 to operate. When the first electromagnet 5 is energized, the hydraulic oil enters the lower vehicle proportional valve 7 to work. When the second electromagnet 6 is energized, the hydraulic oil enters the low-precision proportional three-way flow valve 8 and then flows into the flow distribution valve 10 to work.

[0025] When the action reaches the overflow valve 3 and reaches the overflow state, insufficient engine power may cause engine 2 to stall. At this time, the main pump 1 will automatically adjust the pump displacement and reduce the flow rate so that the pump power cannot exceed the power provided by engine 2, thereby avoiding the occurrence of engine 2 stalling. During the action, the hydraulic oil passes through the low-precision proportional three-way flow valve 8 to the flow distribution valve 10, and then enters the high-precision proportional valve 19 through the second channel 14 to work.

[0026] When operating with low flow rate, the opening of the low-precision proportional three-way flow valve 8 decreases for primary flow regulation, and excess flow returns to the oil tank 24. The hydraulic oil regulated by the low-precision proportional three-way flow valve 8 enters the high-precision proportional valve 19 through the flow distribution valve 10 and the second channel 14 to drive the components. When a small amount of hydraulic oil exceeds the allowable range of the high-precision proportional valve 19, the hydraulic oil flows back to the oil tank 24 through the first throttle orifice 12, the second throttle orifice 17, and the third throttle orifice 23. When the pressure difference across the first throttle orifice 12 reaches a certain value, such that the sum of the spring forces of the second pressure point 15 and the spring 16 is less than the pressure value of the first pressure point 11, the flow distribution valve 10 will switch directions, allowing excess hydraulic oil to flow back to the oil tank 24 through the first channel 13, the third solenoid valve 22, and the check valve 9. Throughout the entire operation, excess hydraulic oil flows back to the oil tank 24 empty, and the overflow valve 3 does not overflow, thus achieving an energy-saving effect.

[0027] When the high-precision proportional valve 19 requires a large flow rate, the low-precision proportional three-way flow valve 8 increases its opening for initial flow regulation, while the high-precision proportional valve 19 performs secondary flow regulation. This allows for energy saving during operation regardless of whether the flow rate is large or small. The low-precision proportional three-way flow valve 8 is closer to the main pump 1 and the oil tank 24 than the high-precision proportional valve 19, and primary speed regulation is performed at this location, allowing excess hydraulic oil to circulate back to the oil tank 24 from a nearby location, thus saving even more energy.

[0028] The first actuator 21 does not require high control precision. It only needs to regulate the flow through the low-precision proportional three-way flow valve 8. At this time, the high-precision proportional valve 19 does not operate. The hydraulic oil enters the second solenoid valve 20 through the first channel 13, which in turn drives the first actuator 21 to work. At this time, the third solenoid valve 22 needs to be energized to prevent the hydraulic oil from returning to the oil tank 24 from the valve. The excess hydraulic oil will also return to the oil tank 24 through the low-precision proportional three-way flow valve 8, which is relatively energy-saving.

[0029] When the proportional valve assembly 30 of the high-precision proportional valve 19 is activated, the hydraulic oil is locked in the actuation pipeline 31 and the second oil outlet pipe 32. The actuation pipeline 31 between the proportional valve assembly 30 and the second actuator 29 is very long. Under these circumstances, there will be no delay in action because the hydraulic oil has been pre-filled in the actuation pipeline 31 and the second oil outlet pipe 32 to avoid the hydraulic oil needing to be refilled over a long distance.

[0030] In addition, the flow rate required by the lower proportional valve 7 is much greater than that required by the high-precision proportional valve 19, and the flow rate required by the actions controlled by the high-precision proportional valve 19 is also different. By adjusting the engine speed 2, different flow rates can be provided for each action. Different actions use different engine speeds, which can save fuel.

[0031] Specifically, engine 2 is connected to main pump 1, and main pump 1 is connected to solenoid valve 4. Solenoid valve 4 includes solenoid 5 and solenoid 6. When solenoid 6 is energized, hydraulic oil flows into flow distribution valve 10 through low-precision proportional three-way flow valve 8. When solenoid 5 is energized, hydraulic oil enters the lower proportional valve 7. Spring 16 on flow distribution valve 10 positions the valve to one side. Flow distribution valve 10 is connected to channel 14. Channel 14 is connected to the valve group of high-precision proportional valve 19. Flow distribution valve 10 is also connected to orifice 12, orifice 17, and orifice 23. In addition, flow distribution valve 10 is also connected to channel 13. Channel 13 is connected to solenoid valve 22 and solenoid valve 20.

[0032] Main pump 1 is a constant power variable pump, and its power is less than that of engine 2 to prevent engine 2 from stalling.

[0033] Hydraulic oil from flow distribution valve 10 normally flows into high-precision proportional valve 19 through channel 2 14. When the flow exceeds the allowable range of high-precision proportional valve 19, the excess flow flows out through channel 13.

[0034] Channel 13 connects to solenoid valve 20 and solenoid valve 22. Solenoid valve 22 is in the H position. Excess flow from channel 13 flows back to tank 24 through check valve 9 via solenoid valve 9.

[0035] There is a one-way valve 9 between oil outlet pipe 26 and oil outlet pipe 32. When it is not activated, it can close the oil circuit of the upper vehicle.

[0036] The low-precision proportional three-way flow valve 8 and the high-precision proportional valve 19 are used together. The low-precision proportional three-way flow valve 8 performs the initial flow adjustment, and the excess flow is directly returned to the oil tank 24. The high-precision proportional valve 19 performs the fine adjustment. The hydraulic oil from the flow distribution valve 10 normally flows into the high-precision proportional valve 19 through the second channel 14. When the flow exceeds the allowable range of the high-precision proportional valve 19, the excess flow flows out through the first channel 13. The first channel 13 is connected to the second solenoid valve 20 and the third solenoid valve 22. The third solenoid valve 22 is in the H position. The excess flow from the first channel 13 flows back to the oil tank 24 through the third solenoid valve 22 in the H position and then through the check valve 9.

[0037] The low-precision proportional three-way flow valve 8 and the higher-precision proportional valve 19 are closer to the main pump 1 and the oil tank 24. During primary speed regulation, excess hydraulic oil can flow back to the oil tank 24 in a shorter distance, reducing energy loss.

[0038] When the action of actuator 21 does not require high proportional adjustment, the flow rate can be adjusted by using a low-precision proportional three-way flow valve 8 alone.

[0039] Engine 2 can adjust its speed according to flow demand to save fuel.

[0040] Furthermore, it should be noted that the specific embodiments described in this specification may differ in the shape and name of their components. The above description is merely illustrative of the structure of this utility model. All equivalent or simple variations made based on the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, all of which should fall within the protection scope of this utility model.

Claims

1. An energy-saving hydraulic control system for an aerial work platform, comprising a main pump (1), an engine (2), an overflow valve (3), a first solenoid valve (4), a lowering proportional valve (7), a low-precision proportional three-way flow valve (8), a check valve (9), a high-precision proportional valve (19), a second solenoid valve (20), a third solenoid valve (22), an oil tank (24), a first oil inlet pipe (25), a first oil outlet pipe (26), a second oil outlet pipe (32), a second oil inlet pipe (27), and a third oil inlet pipe (28), characterized in that: The first oil inlet pipe (25) is connected to the first solenoid valve (4) and the oil tank (24) at both ends, the first oil outlet pipe (26) is connected to the one-way valve (9) and the oil tank (24) at both ends, the second oil outlet pipe (32) is connected to the one-way valve (9) and the high-precision proportional valve (19) at both ends, the second oil inlet pipe (27) is connected to the high-precision proportional valve (19) and the first solenoid valve (4) at both ends, the third oil inlet pipe (28) is connected to the first solenoid valve (4) and the undercarriage proportional valve (7) at both ends, the main pump (1) is connected to the engine (2), the main pump (1) and the overflow valve (3) are both installed on the first oil inlet pipe (25), the low-precision proportional three-way flow valve (8) is installed on the second oil inlet pipe (27), the second solenoid valve (20) and the third solenoid valve (22) are both connected to the high-precision proportional valve (19).

2. The energy-saving aerial work platform hydraulic control system according to claim 1, characterized in that: The first solenoid valve (4) is equipped with a first electromagnet (5) and a second electromagnet (6).

3. The energy-saving aerial work platform hydraulic control system according to claim 1, characterized in that: The second solenoid valve (20) is connected to the first actuator (21).

4. The energy-saving aerial work platform hydraulic control system according to claim 1, characterized in that: It also includes a flow distribution valve (10), which is connected to a spring (16). The flow distribution valve (10) is connected to a first channel (13) and a second channel (14). The first channel (13) is connected to a second solenoid valve (20) and a third solenoid valve (22). The high-precision proportional valve (19) includes multiple proportional valve groups (30). The second channel (14) is connected to multiple proportional valve groups (30). The multiple proportional valve groups (30) are connected to the second actuator (29) through an actuation pipeline (31).

5. The energy-saving aerial work platform hydraulic control system according to claim 4, characterized in that: The flow distribution valve (10) is connected to the first throttle orifice (12), the second throttle orifice (17), and the third throttle orifice (23).

6. The energy-saving aerial work platform hydraulic control system according to claim 1, characterized in that: The low-precision proportional three-way flow valve (8) and the high-precision proportional valve (19) constitute the upper vehicle proportional valve. The upper vehicle proportional valve is used to control the upper part of the vehicle to move, and the lower vehicle proportional valve (7) is used to control the lower part of the vehicle to move.

7. The energy-saving aerial work platform hydraulic control system according to claim 1, characterized in that: The high-precision proportional valve (19) is located after the central rotating body (18), and the low-precision proportional three-way flow valve (8) is located before the central rotating body (18).

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