Hydraulic system capable of realizing emergency descending of crank arm type overhead working truck

Abstract

The utility model discloses a hydraulic system capable of realizing emergency descending of a crank arm type overhead working truck, which comprises an oil tank, a motor, a hydraulic pump, a balance valve group, a working oil cylinder group and an integrated valve group, the working oil cylinder group comprises a main arm oil cylinder, a fly arm oil cylinder, a folding arm oil cylinder, a leveling oil cylinder and a steering oil cylinder, the balance valve group comprises a fly jib balance valve group connected with the fly jib and cylinder, a main jib balance valve group connected with the main jib oil cylinder, and a folding jib balance valve group connected with the folding jib oil cylinder; the integrated valve group comprises an oil inlet path and an oil return path; the balance valve group is respectively communicated with the oil inlet path and the oil return path, and the working oil cylinder group is respectively communicated with the oil inlet path and the oil return path. The hydraulic system is simple, and the manual emergency descending function of more oil cylinders is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic control, and in particular to a hydraulic system that can realize the emergency descent of a boom-type aerial work platform. Background Art

[0002] A boom-type aerial work platform is a lifting device used for aerial work. Compared with a scissor-type aerial work platform, the boom-type aerial work platform can cross obstacles to perform aerial work, and the platform can move and work while ascending or descending to any position. Boom-type aerial work platforms are widely applicable to installation, maintenance, and climbing operations in industries such as municipal engineering, electric power, street lighting, advertising, communication, gardening, and large industrial and mining enterprises. When the main oil supply system of the hydraulic system of an aerial work platform encounters an emergency where it cannot work properly, such as a malfunction of the engine or a problem with the main oil pump, etc., an emergency system is required to retract the working arm (such as a boom or a ladder) of the aerial work vehicle. In the prior art, the hydraulic system of a boom-type aerial work platform generally can only control the emergency descent of one or two corresponding oil cylinders and cannot control all oil cylinders to perform emergency descent, which is likely to cause safety accidents in case of an emergency.

[0003] The prior art patent with the application number CN201911249363.8 discloses a hydraulic system for a boom-type aerial work platform, including a work platform hydraulic system. The work platform hydraulic system includes a work platform auxiliary pump, a leveling oil cylinder, a folding oil cylinder, a swing motor, and a work platform integrated valve block. The work platform integrated valve block includes a second oil inlet circuit and a second oil return circuit. The leveling oil cylinder, the folding oil cylinder, and the swing motor are all connected to the second oil inlet circuit and the second oil return circuit. This patent cannot realize the emergency descent of all oil cylinders. Summary of the Invention

[0004] The main problem to be solved by the utility model is that in the prior art, the hydraulic system of a boom-type aerial work platform can only control the emergency descent of one or two oil cylinders and cannot control all oil cylinders to perform emergency descent. The utility model provides a hydraulic system that can realize the emergency descent of a boom-type aerial work platform.

[0005] In view of the above technical problems, the technical solution of the utility model is as follows:

[0006] A hydraulic system that can achieve emergency descent of a knuckle boom aerial work platform, including an oil tank, a motor, and a hydraulic pump, further including a balance valve group, a working cylinder group, and an integrated valve group. The working cylinder group includes a main boom cylinder, a fly boom cylinder, a folding boom cylinder, a leveling cylinder, and a steering cylinder. The balance valve group includes a fly boom balance valve group connected to the fly boom cylinder, a main boom balance valve group connected to the main boom cylinder, and a folding boom balance valve group connected to the folding boom cylinder. The integrated valve group includes an oil inlet circuit and an oil return circuit. The balance valve group is respectively communicated with the oil inlet circuit and the oil return circuit, and the working cylinder group is respectively communicated with the oil inlet circuit and the oil return circuit.

[0007] Further, the integrated valve group includes a solenoid valve, a manual pump, and a manual reversing valve. There are a total of five solenoid valves, and the manual pump is connected to the manual reversing valve.

[0008] Further, when the hydraulic system is in a normal working state, the manual reversing valve is in a cut-off state.

[0009] Further, the solenoid valve is a three-position four-way solenoid valve. The main boom cylinder is communicated with the first solenoid valve, the fly boom cylinder is communicated with the second solenoid valve, the folding boom cylinder is communicated with the third solenoid valve, the leveling cylinder is communicated with the fourth solenoid valve, and the steering cylinder is communicated with the fifth solenoid valve.

[0010] Further, all the three-position four-way solenoid valves have a manual emergency reversing function.

[0011] Further, the integrated valve group further includes a relief valve and a two-position two-way solenoid valve. The relief valve and the two-position two-way solenoid valve are arranged in parallel in the oil return circuit.

[0012] Further, the integrated valve further includes a hydraulic lock. The two hydraulic locks are respectively communicated with the rod chamber and the non-rod chamber of the leveling cylinder.

[0013] Further, the main boom balance valve group is respectively connected to the rod chamber and the non-rod chamber of the main boom cylinder.

[0014] Further, the fly boom balance valve group is respectively connected to the rod chamber and the non-rod chamber of the fly boom cylinder.

[0015] Further, the folding boom balance valve group is respectively connected to the rod chamber and the non-rod chamber of the folding boom cylinder.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] The utility model provides mechanical energy for a hydraulic pump through a motor. The two-position two-way solenoid valve on the integrated valve block is energized to change its direction. The five solenoid valves respectively control the extension and retraction of different oil cylinders. The main boom balance valve block, fly boom balance valve block, and folding boom balance valve block respectively maintain the oil cylinder load when the corresponding oil cylinders extend. And a hydraulic lock is used to ensure that there is no oil leakage in the leveling oil rod. When performing emergency descent control, the manual reversing valve 20 changes its direction, and then oil is pumped from the T port to the P port through a manual pump. At the same time, the two-position two-way solenoid valve is energized to change its direction, and the right coil of the solenoid valve is energized to change its direction, causing the main boom oil cylinder to contract; the right coil of the solenoid valve is energized to change its direction, causing the fly boom oil cylinder to contract; the right coil of the solenoid valve is energized to change its direction, causing the folding boom oil cylinder to contract; the right coil of the solenoid valve is energized to change its direction, causing the leveling oil cylinder to contract; the right coil of the solenoid valve is energized to change its direction, causing the steering oil cylinder to contract, which can realize the emergency descent of all oil cylinder actions of the articulated boom aerial work platform, improve the safety of the aerial work platform, and the hydraulic system has a simple structure and is easy to maintain. Brief Description of the Drawings

[0018] Figure 1 It is a schematic hydraulic principle diagram of a hydraulic system that can realize the emergency descent of an aerial work platform;

[0019] In the schematic diagram: 1. oil tank; 2. motor; 3. hydraulic pump; 4. two-position two-way solenoid valve; 5. overflow valve; 6. first solenoid valve; 7. main boom balance valve block; 8. main boom oil cylinder; 9. second solenoid valve; 10. fly boom balance valve block; 11. fly boom oil cylinder; 12. third solenoid valve; 13. folding boom balance valve block; 14. folding boom oil cylinder; 15. fourth solenoid valve; 16. hydraulic lock; 17. leveling oil cylinder; 18. fifth solenoid valve; 19. steering oil cylinder; 20 manual reversing valve; 21. manual pump; 22. oil inlet circuit; 23. oil return circuit. Detailed Description of the Preferred Embodiments

[0020] To clearly illustrate the technical features of the application solution of the utility model, the utility model will be described in detail below through specific embodiments and in conjunction with its drawings.

[0021] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application may be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless specifically defined otherwise.

[0023] In this application, unless otherwise clearly defined and limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0025] Embodiment 1

[0026] As Figure 1 shown, a hydraulic system capable of realizing the emergency descent of a boom-type aerial work vehicle includes an oil tank 1, a motor 2, and a hydraulic pump 3, and also includes a balance valve group, a working oil cylinder group, and an integrated valve group. The working oil cylinder group includes a main boom oil cylinder 8, a fly boom oil cylinder 11, a folding boom oil cylinder 14, a leveling oil cylinder 17, and a steering oil cylinder 19. The balance valve group includes a fly boom balance valve group 10 connected to the fly boom oil cylinder 11, a main boom balance valve group 7 connected to the main boom oil cylinder 8, and a folding boom balance valve group 13 connected to the folding boom oil cylinder 14. The integrated valve group includes an oil inlet circuit 22 and an oil return circuit 23. The balance valve group is respectively communicated with the oil inlet circuit 22 and the oil return circuit 23, and the working oil cylinder group is respectively communicated with the oil inlet circuit 22 and the oil return circuit 23.

[0027] In this embodiment, the integrated valve group includes a solenoid valve, a manual pump 21, and a manual directional control valve 20. There are a total of five solenoid valves. The manual pump 21 is connected to the manual directional control valve 20. The solenoid valve is a three-position four-way solenoid valve. The first solenoid valve 6 is respectively communicated with the rod chamber and the rodless chamber of the main boom cylinder 8. The second solenoid valve 9 is respectively communicated with the rod chamber and the rodless chamber of the fly boom cylinder 11. The third solenoid valve 12 is respectively communicated with the rod chamber and the rodless chamber of the folding boom cylinder 14. The fourth solenoid valve 15 is respectively communicated with the rod chamber and the rodless chamber of the leveling cylinder 17. The fifth solenoid valve 18 is respectively communicated with the rod chamber and the rodless chamber of the steering cylinder 19. And all the three-position four-way solenoid valves are equipped with a manual emergency directional control function.

[0028] The integrated valve group further includes a relief valve and a two-position two-way solenoid valve. The relief valve 5 and the two-position two-way solenoid valve 4 are connected in parallel in the oil return circuit 23. The inlet of the relief valve 5 is connected to the P port of the oil inlet circuit 22, and the outlet of the relief valve 5 is connected to the T port of the oil return circuit 23. The relief valve 5 is a normally closed relief valve, and the relief valve 5 controls the maximum pressure of the whole system. The two ends of the two-position two-way solenoid valve 4 are respectively connected to the oil inlet circuit 22 and the oil return circuit 23. The integrated valve further includes a hydraulic lock 16. The two hydraulic locks 16 are respectively connected to the rod chamber and the rodless chamber of the leveling cylinder 17. The fourth solenoid valve 15 is connected to the inlet of the hydraulic lock 16, and the outlet of the hydraulic lock 16 is respectively connected to the rod chamber and the rodless chamber of the leveling cylinder 17.

[0029] Such as Figure 1As shown, in this example, the motor 2 provides mechanical energy for the hydraulic pump 3, enabling the hydraulic pump 3 to supply oil to the entire hydraulic system. When the two-position two-way solenoid valve 4 is energized, the right position of the two-position two-way solenoid valve 4 works. At this time, the right-side coil of the first solenoid valve 6 is energized, and no other solenoid valves are energized. The pressure oil output by the hydraulic pump 3 reaches the main boom balance valve group 7 through the P port of the oil inlet passage 22 and the right position of the first solenoid valve 6. The hydraulic oil enters the rodless cavity of the main boom cylinder 8 through the main boom balance valve group 7, causing the main boom cylinder 8 to extend. At the same time, the hydraulic oil in the rod chamber of the main boom cylinder 8 returns to the fuel tank 1 through the oil return passage 23. When the left-side coil of the first solenoid valve 6 is energized, the pressure oil output by the hydraulic pump 3 enters the rod chamber of the main boom cylinder 8 through the left position of the first solenoid valve 6, causing the main boom cylinder 8 to retract. At the same time, the hydraulic oil in the rodless cavity of the main boom cylinder 8 returns to the fuel tank 1 through the oil return passage 23. When the right-side coil and the left-side coil of the second solenoid valve 9 are energized respectively, the pressure oil output by the hydraulic pump 3 reaches the fly boom balance valve group 10 through the oil inlet passage 22 and the second solenoid valve 9, and then enters the rodless cavity and the rod chamber of the fly boom cylinder 11 respectively, controlling the extension and retraction of the fly boom cylinder 11. When the right-side coil and the left-side coil of the third solenoid valve 12 are energized respectively, the pressure oil output by the hydraulic pump 3 reaches the folding boom balance valve group 13 through the oil inlet passage 22 and the third solenoid valve 12, and then enters the rodless cavity and the rod chamber of the folding boom cylinder 14 respectively, controlling the extension and retraction of the folding boom cylinder 14. When the right-side coil and the left-side coil of the fourth solenoid valve 15 are energized respectively, the pressure oil output by the hydraulic pump 3 reaches the hydraulic lock 16 through the oil inlet passage 22 and the fourth solenoid valve 15, and then enters the rodless cavity and the rod chamber of the leveling cylinder 17 respectively after passing through the hydraulic lock 16, controlling the extension and retraction of the leveling cylinder 17. When the right-side coil and the left-side coil of the fifth solenoid valve 18 are energized respectively, the pressure oil output by the hydraulic pump 3 reaches the steering cylinder 19 through the oil inlet passage 22 and the fifth solenoid valve 18, controlling the extension and retraction of the steering cylinder 19. The oil outlets of the hydraulic lock 16 are respectively connected to the rod chamber and the rodless cavity of the leveling cylinder 17, which can ensure that the leveling cylinder 17 does not leak oil.

[0030] Among them, the main boom balance valve group 7, the fly boom balance valve group 10, and the folding boom balance valve group 13 mainly ensure the load of the cylinders when the main boom cylinder 8, the fly boom cylinder 11, and the folding boom cylinder 14 extend, maintain the load stability, and thus ensure the smooth movement when the cylinders extend.

[0031] Embodiment 2

[0032] As Figure 1As shown in the figure, a hydraulic system for realizing the emergency descent of a articulated boom aerial work platform includes an oil tank 1, a motor 2, and a hydraulic pump 3. It also includes a balance valve group, a working cylinder group, and an integrated valve group. The working cylinder group includes a main boom cylinder 8, a fly boom cylinder 11, a folding boom cylinder 14, a leveling cylinder 17, and a steering cylinder 19. The balance valve group includes a fly boom balance valve group 10 connected to the fly boom cylinder 11, a main boom balance valve group 7 connected to the main boom cylinder 8, and a folding boom balance valve group 13 connected to the folding boom cylinder 14. The integrated valve group includes an oil inlet circuit 22 and an oil return circuit 23. The balance valve group is respectively connected to the oil inlet circuit 22 and the oil return circuit 23, and the working cylinder group is respectively connected to the oil inlet circuit 22 and the oil return circuit 23.

[0033] In this embodiment, when using this system for emergency descent control, the manual reversing valve 20 is reversed, and the manual pump 21 is controlled so that the output hydraulic oil flows from the T port to the P port. At the same time, the two-position two-way solenoid valve 4 is energized and reversed, and the left coil of the first solenoid valve 6 is energized. The hydraulic oil enters the rod chamber of the main boom cylinder 8 through the main boom balance valve group 7, causing the main boom cylinder 8 to retract. When the left coil of the second solenoid valve 9 is energized and reversed, the hydraulic oil enters the rod chamber of the fly boom cylinder 11 through the fly boom balance valve group 10, causing the fly boom cylinder 11 to retract. When the left coil of the third solenoid valve 12 is energized and reversed, the hydraulic oil enters the rod chamber of the folding boom cylinder 14 through the folding boom balance valve group 13, causing the folding boom cylinder 14 to retract. When the left coil of the fourth solenoid valve 15 is energized, the fourth solenoid valve 15 is reversed, and the hydraulic oil enters the rod chamber of the leveling cylinder 17 through the hydraulic lock 16, causing the leveling cylinder 17 to retract. When the left coil of the fifth solenoid valve 18 is energized, the fifth solenoid valve 18 is energized and reversed, and the hydraulic oil enters the rod chamber of the steering cylinder 19 through the fifth solenoid valve 18, causing the steering cylinder 19 to retract. By this method, the emergency descent of all cylinders of the articulated boom aerial work platform is realized, with simple operation and stable system operation.

[0034] Embodiment 3

[0035] As Figure 1 As shown in the figure, a hydraulic system for realizing the emergency descent of a articulated boom aerial work platform includes an oil tank 1, a motor 2, and a hydraulic pump 3. It also includes a balance valve group, a working cylinder group, and an integrated valve group. The working cylinder group includes a main boom cylinder 8, a fly boom cylinder 11, a folding boom cylinder 14, a leveling cylinder 17, and a steering cylinder 19. The balance valve group includes a fly boom balance valve group 10 connected to the fly boom cylinder 11, a main boom balance valve group 7 connected to the main boom cylinder 8, and a folding boom balance valve group 13 connected to the folding boom cylinder 14. The integrated valve group includes an oil inlet circuit 22 and an oil return circuit 23. The balance valve group is respectively connected to the oil inlet circuit 22 and the oil return circuit 23, and the working cylinder group is respectively connected to the oil inlet circuit 22 and the oil return circuit 23.

[0036] All solenoid valves are equipped with a manual emergency commutation function. Even in the event of an electrical failure in the vehicle, the solenoid valve can be commutated manually, so that the corresponding oil cylinder can perform a manual emergency descent, improving safety. When the main hydraulic pump of the aerial work platform is working, the manual commutation valve 20 is in the cut-off state, so that the pressure oil at the P port of the oil inlet circuit will not flow through the manual commutation valve 20 and the manual pump 21 to the T port, and will not affect the normal operation of the hydraulic system.

[0037] This hydraulic system can appropriately increase the actuators as needed. By installing a solenoid valve with a manual emergency commutation function in the system, the actuators such as motors and oil cylinders can achieve emergency descent.

[0038] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A hydraulic system capable of realizing emergency descent of a knuckle boom aerial work platform, comprising an oil tank, a motor and a hydraulic pump, characterized in that, It also includes a balance valve group, a working oil cylinder group and an integrated valve group. The working oil cylinder group includes a main boom oil cylinder, a fly boom oil cylinder, a folding boom oil cylinder, a leveling oil cylinder and a steering oil cylinder. The balance valve group includes a fly boom balance valve group connected to the fly boom oil cylinder, a main boom balance valve group connected to the main boom oil cylinder, and a folding boom balance valve group connected to the folding boom oil cylinder. The integrated valve group includes an oil inlet circuit and an oil return circuit. The balance valve group is respectively communicated with the oil inlet circuit and the oil return circuit, and the working oil cylinder group is respectively communicated with the oil inlet circuit and the oil return circuit.

2. The hydraulic system for realizing the emergency descent of a knuckle boom aerial work platform according to claim 1, characterized in that, The integrated valve group includes a solenoid valve, a manual pump and a manual reversing valve. There are five solenoid valves in total, and the manual pump is connected to the manual reversing valve.

3. A hydraulic system for realizing the emergency descent of a knuckle boom aerial work platform according to claim 2, characterized in that, Under the normal working state of the hydraulic system, the manual reversing valve is in a cut-off state.

4. A hydraulic system for realizing emergency descent of a knuckle boom aerial work platform according to claim 2, characterized in that, The solenoid valve is a three-position four-way solenoid valve. The main boom oil cylinder is communicated with the first solenoid valve, the fly boom oil cylinder is communicated with the second solenoid valve, the folding boom oil cylinder is communicated with the third solenoid valve, the leveling oil cylinder is communicated with the fourth solenoid valve, and the steering oil cylinder is communicated with the fifth solenoid valve.

5. A hydraulic system for realizing emergency descent of a knuckle boom aerial work platform according to claim 4, characterized in that, All of the three-position four-way solenoid valves are equipped with a manual emergency reversing function.

6. The hydraulic system for realizing the emergency descent of the articulated boom aerial work platform according to claim 2, characterized in that, The integrated valve group also includes an overflow valve and a two-position two-way solenoid valve. The overflow valve and the two-position two-way solenoid valve are connected in parallel in the oil return circuit.

7. A hydraulic system for realizing the emergency descent of a knuckle boom aerial work platform according to claim 6, characterized in that, The integrated valve also includes a hydraulic lock. The two hydraulic locks are respectively communicated with the rod chamber and the non-rod chamber of the leveling oil cylinder.

8. A hydraulic system for realizing emergency descent of a knuckle boom aerial work platform according to claim 1, characterized in that, The main boom balance valve group is respectively connected to the rod chamber and the non-rod chamber of the main boom oil cylinder.

9. A hydraulic system for realizing emergency descent of a knuckle boom aerial work platform according to claim 1, characterized in that, The fly boom balance valve group is respectively connected to the rod chamber and the non-rod chamber of the fly boom oil cylinder.

10. A hydraulic system for realizing emergency descent of a knuckle boom aerial work platform according to claim 1, characterized in that, The folding boom balance valve group is respectively connected to the rod chamber and the non-rod chamber of the folding boom oil cylinder.

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