Supporting leg protection system of cross-country scissor-type overhead working truck

Abstract

The invention discloses a support leg protection system of a cross-country scissor-type overhead working truck, which relates to the technical field of overhead working and comprises an oil tank, a motor, a gear pump, an overflow valve, a three-position four-way electromagnetic directional valve, a plurality of support leg control valves, a plurality of support leg oil cylinders and a hydraulic control one-way valve. The hydraulic control one-way valve is arranged in the oil return path of the supporting leg oil cylinder, and the Y-shaped middle position structure of the three-position four-way electromagnetic reversing valve is combined, so that automatic oil way locking and residual pressure release can be realized when the supporting leg does not act; and the phenomenon that the supporting legs automatically retract or fall off due to the factors such as overlong parking time, vehicle running on bumpy road sections and micro leakage of the oil cylinder is effectively avoided, so that the supporting leg oil cylinder is protected, the overall stability of the aerial work platform and the running safety of the whole vehicle are improved, and the service life of equipment is prolonged.

Description

Technical Field

[0001] This invention relates to the field of aerial work technology, and more specifically, to a scissor lift aerial work platform outrigger protection system. Background Technology

[0002] Aerial work platforms are equipment used to transport personnel, tools, and materials to designated locations for work. When traveling, the four outriggers of an off-road scissor lift are retracted; during operation, they are extended to ensure stability and safety during aerial work. Currently, most manufacturers use a single directional valve and four outrigger control valves to drive the extension and retraction of the four outriggers. The traditional outrigger control principle is as follows: Figure 4 As shown, before the aerial work platform vehicle enters the working state, its traditional leg extension hydraulic principle is as follows: Figure 5 As shown, when the aerial work platform is in a stationary or moving state, the outriggers are in a retracted state. The traditional retraction principle is as follows: Figure 6 As shown.

[0003] Since the existing three-position four-way solenoid directional valve is a spool valve, leakage is inevitable inside (the internal pressure oil in the pipeline connecting the A and B ports to the outrigger valve leaks back to the oil tank through the "O-type" neutral position function). When the parking time is too long, or when driving on bumpy roads, or when there is a slight leakage in the cylinder, the cylinder may fall off (the cylinder may extend), which will have an adverse effect on driving safety and the life of the whole machine and the cylinder.

[0004] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0005] In response to the problems in related technologies, this invention proposes an outrigger protection system for off-road scissor lift aerial work platforms to overcome the aforementioned technical problems existing in the prior art.

[0006] Therefore, the specific technical solution adopted by the present invention is as follows: A trailing leg protection system for an off-road scissor lift aerial work platform includes: an oil tank, an electric motor, a gear pump, an overflow valve, a three-position four-way solenoid directional valve, several trailing leg control valves, several trailing leg cylinders, and a hydraulically controlled check valve. The hydraulic oil tank is connected to the gear pump via an electric motor; the gear pump is connected to the relief valve; the gear pump is also connected to a three-position four-way solenoid directional valve; the three-position four-way solenoid directional valve is connected to a hydraulically controlled check valve; the hydraulically controlled check valve is connected to several outrigger control valves; the several outrigger control valves are respectively connected to their corresponding outrigger cylinders; and the relief valve is connected to the hydraulic oil tank.

[0007] Furthermore, the oil inlet of the gear pump is connected to the oil tank via a pipeline. The gear pump is driven to rotate by an electric motor and draws oil from the oil tank.

[0008] Furthermore, the oil outlet of the gear pump is connected in parallel to the V port of the relief valve and the P port of the three-position four-way solenoid directional valve via pipelines.

[0009] Furthermore, the C port of the overflow valve is connected in parallel to the T port of the three-position four-way solenoid directional valve to the return oil of oil tank 1.

[0010] Furthermore, the A port of the three-position four-way solenoid directional valve is connected to the V3 port of the pilot-operated check valve; the B port of the three-position four-way solenoid directional valve is connected to the V4 port of the pilot-operated check valve, and the switching direction of the three-position four-way solenoid directional valve is controlled by solenoid valves SV1 and SV2.

[0011] Furthermore, the C3 port of the hydraulic control check valve is connected to the V1 port of several outrigger control valves via a tee connector, and the C4 port of the hydraulic control check valve is connected to the V2 port of several outrigger control valves via a tee connector.

[0012] Furthermore, the C1 ports of several outrigger control valves are respectively connected to the rodless chambers of several outrigger cylinders, and the C2 ports of several outrigger control valves are respectively connected to the rod chambers of several outrigger cylinders.

[0013] Furthermore, several outrigger control valves are controlled by solenoid valves SV3, SV4, SV5, and SV6 respectively. When solenoid valves SV3, SV4, SV5, and SV6 are energized, the V1 port of several outrigger control valves is connected to the C1 port of several outrigger control valves, and the V2 port of several outrigger control valves is connected to the C2 port of several outrigger control valves respectively.

[0014] Furthermore, the C3 port of the hydraulic control check valve and the V3 port of the hydraulic control check valve form a return oil path, which is connected to the A port of the three-position four-way solenoid directional valve and is used to conduct oil to the oil tank when the outrigger cylinder returns oil.

[0015] Furthermore, when the three-position four-way solenoid directional valve is in the neutral position, port A of the three-position four-way solenoid directional valve is simultaneously connected to port T of the three-position four-way solenoid directional valve, and port B of the three-position four-way solenoid directional valve is simultaneously connected to port T of the three-position four-way solenoid directional valve. Port T of the three-position four-way solenoid directional valve is connected to the oil return of the oil tank.

[0016] The beneficial effects of this invention are as follows: by setting a hydraulic control check valve in the oil return path of the outrigger cylinder and combining it with the Y-type mid-position structure of the three-position four-way solenoid directional valve, the oil circuit can be automatically locked and residual pressure released when the outrigger is not in motion. This effectively avoids the phenomenon of automatic retraction or falling of the outrigger caused by factors such as excessive parking time, vehicle driving on bumpy roads, and minor leakage of the cylinder, thereby protecting the outrigger cylinder, improving the overall stability of the aerial work platform and the safety of the vehicle, and extending the service life of the equipment. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the hydraulic control principle of the outrigger protection system for an off-road scissor lift aerial work platform according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the hydraulic principle of the outrigger protection system for an off-road scissor lift aerial work platform according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the retraction hydraulic principle of the outrigger protection system for an off-road scissor lift aerial work platform according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the conventional outrigger control hydraulic principle according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the conventional leg extension hydraulic principle according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the conventional retractable leg hydraulic principle according to an embodiment of the present invention.

[0019] In the picture: 1. Oil tank; 2. Electric motor; 3. Gear pump; 4. Overflow valve; 5. Three-position four-way solenoid directional valve; 6. Outrigger control valve; 7. Outrigger cylinder; 8. Hydraulic check valve. Detailed Implementation

[0020] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention.

[0021] According to an embodiment of the present invention, a scissor lift outrigger protection system is provided for an off-road scissor lift aerial work platform.

[0022] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figures 1-3 As shown, the outrigger protection system of the off-road scissor lift aerial work vehicle according to an embodiment of the present invention includes: an oil tank 1, an electric motor 2, a gear pump 3, an overflow valve 4, a three-position four-way solenoid directional valve 5, a plurality of outrigger control valves 6, a plurality of outrigger cylinders 7, and a hydraulic control check valve 8. The hydraulic oil tank 1 is connected to the gear pump 3 via the electric motor 2; the gear pump 3 is connected to the relief valve 4; the gear pump 3 is also connected to the three-position four-way solenoid directional valve 5; the three-position four-way solenoid directional valve 5 is connected to the hydraulic control check valve 8; the hydraulic control check valve 8 is connected to several outrigger control valves 6; the several outrigger control valves 6 are respectively connected to the corresponding outrigger cylinders 7; and the relief valve 4 is connected to the hydraulic oil tank 1.

[0023] In one embodiment, the oil suction port of the gear pump 3 is connected to the oil tank 1 through a pipeline, and the gear pump 3 is driven to rotate by the motor 2 and draws oil from the oil tank 1.

[0024] In one embodiment, the oil outlet of the gear pump 3 is connected in parallel to the V port of the overflow valve 4 and the P port of the three-position four-way solenoid directional valve 5 via a pipeline.

[0025] In one embodiment, the C port of the overflow valve 4 is connected in parallel to the T port of the three-position four-way solenoid directional valve 5 to the oil return port of the oil tank 1.

[0026] In one embodiment, the A port of the three-position four-way solenoid directional valve 5 is connected to the V3 port of the hydraulic control check valve 8; the B port of the three-position four-way solenoid directional valve 5 is connected to the V4 port of the hydraulic control check valve 8, and the switching direction of the three-position four-way solenoid directional valve 5 is controlled by solenoid valves SV1 and SV2.

[0027] In one embodiment, the C3 port of the hydraulic check valve 8 is connected to the V1 port of several outrigger control valves 6 via a tee connector, and the C4 port of the hydraulic check valve 8 is connected to the V2 port of several outrigger control valves 6 via a tee connector.

[0028] In one embodiment, the C1 ports of several outrigger control valves 6 are respectively connected to the rodless chambers of several outrigger cylinders 7, and the C2 ports of several outrigger control valves 6 are respectively connected to the rod chambers of several outrigger cylinders 7.

[0029] In one embodiment, a plurality of outrigger control valves 6 are controlled by solenoid valves SV3, SV4, SV5 and SV6 respectively. When solenoid valves SV3, SV4, SV5 and SV6 are energized, the V1 port of the plurality of outrigger control valves 6 is connected to the C1 port of the plurality of outrigger control valves 6, and the V2 port of the plurality of outrigger control valves 6 is connected to the C2 port of the plurality of outrigger control valves 6 respectively.

[0030] In one embodiment, the C3 port of the hydraulic control check valve 8 and the V3 port of the hydraulic control check valve 8 form a return oil path, which is connected to the A port of the three-position four-way solenoid directional valve 5 and is used to conduct oil to the oil tank 1 when the outrigger cylinder 7 returns oil.

[0031] In one embodiment, when the three-position four-way solenoid directional valve 5 is in the neutral position, the A port of the three-position four-way solenoid directional valve 5 is simultaneously connected to the T port of the three-position four-way solenoid directional valve 5, and the B port of the three-position four-way solenoid directional valve 5 is simultaneously connected to the T port of the three-position four-way solenoid directional valve 5. The T port of the three-position four-way solenoid directional valve 5 is connected to the return oil of the oil tank 1.

[0032] It needs to be explained that, for example Figure 4 As shown, the traditional outrigger control principle includes the following components: oil tank 1, electric motor 2, gear pump 3, overflow valve 4, three-position four-way solenoid valve 5, four outrigger control valves 6, and four outrigger cylinders 7. The gear pump 3's suction port is connected to the oil tank 1. The electric motor 2 directly drives the gear pump 3 to rotate and draw oil from the oil tank 1. The gear pump 3's outlet port is connected in parallel with the V port of the overflow valve 4 and the P port of the three-position four-way solenoid valve 5. The overflow valve 4's C port is connected in parallel with the T port of the three-position four-way solenoid valve 5 back to the oil tank 1. The three-position four-way solenoid valve 5's A port is connected to the V1 port of the four outrigger control valves 6 via a three-way connector. The three-position four-way solenoid valve 5's B port is connected to the V2 port of the four outrigger control valves 6 via a three-way connector. The four outrigger control valves 6's C1 port is connected to the rodless chamber of the four outrigger cylinders 7. The four outrigger control valves 6's C2 port is connected to the rod chamber of the four outrigger cylinders 7.

[0033] The oil tank 1 is used to store hydraulic oil, the electric motor 2 serves as the power source, the gear pump 3 supplies oil to the system, the overflow valve 4 prevents system overload and plays a protective role, the three-position four-way solenoid directional valve 5 is used to change the flow direction of hydraulic oil, the four outrigger control valves 6 control the status of the outriggers and maintain the load, and the four outrigger cylinders 7 are responsible for lifting the aerial work platform off the ground as a whole.

[0034] It needs to be explained that, for example Figure 5As shown, the traditional hydraulic principle for extending the legs includes: hydraulic oil flows out through gear pump 3 and enters the P port of the three-position four-way solenoid directional valve 5. Solenoid valve SV1 of the three-position four-way solenoid directional valve 5 is energized, connecting the P port of the three-position four-way solenoid directional valve 5 with the A port, and the B port of the three-position four-way solenoid directional valve 5 with the T port. Hydraulic oil flows out through the A port of the three-position four-way solenoid directional valve 5 and enters the V1 port of the four outrigger control valves 6. At this time, solenoid valves SV3, SV4, SV5, and SV6 of the four outrigger control valves 6 are energized, causing the four outrigger control valves 6 to... The V1 port is connected to the C1 port of the four outrigger control valves 6. Hydraulic oil flows out through the C1 port of the four outrigger control valves 6 and enters the rodless chamber of the four outrigger cylinders 7. The hydraulic oil in the rod chamber of the four outrigger cylinders 7 returns to the oil tank 1 through the C2 port of the four outrigger control valves 6, the V2 port of the four outrigger control valves 6, the B port of the three-position four-way solenoid directional valve 5, and the T port of the three-position four-way solenoid directional valve 5. At this time, the four outrigger cylinders 7 extend. After the four outrigger cylinders 7 extend, all the solenoid valves of the three-position four-way solenoid directional valve 5 and the four outrigger control valves 6 are de-energized. The four outrigger control valves 6 lock the rodless chamber of the four outrigger cylinders 7 and enter the high-altitude operation state.

[0035] It needs to be explained that, for example Figure 6 As shown, the traditional hydraulic principle for outrigger retraction includes: hydraulic oil flows out through gear pump 3 and enters the P port of three-position four-way solenoid directional valve 5. Solenoid valve SV2 of three-position four-way solenoid directional valve 5 is energized, connecting the P port of three-position four-way solenoid directional valve 5 with its B port, and connecting the A port of three-position four-way solenoid directional valve 5 with its T port. Hydraulic oil flows out through the B port of three-position four-way solenoid directional valve 5 and enters the V2 port of four outrigger control valves 6. At this time, solenoid valves SV3, SV4, SV5, and SV6 of the four outrigger control valves 6 are energized, connecting the V1 port of the four outrigger control valves 6 with the four outrigger control valves 6. When port C1 of valve 6 is connected, the check valves inside the four outrigger control valves 6 are simultaneously opened. Hydraulic oil flows out through port C2 of the four outrigger control valves 6 and enters the rod chamber of the four outrigger cylinders 7. Hydraulic oil in the rodless chamber of the four outrigger cylinders 7 returns to the oil tank 1 through ports C1 and V1 of the four outrigger control valves 6, and ports A and T of the three-position four-way solenoid directional valve 5. At this time, the four outrigger cylinders 7 retract. After the four outrigger cylinders 7 retract, all solenoid valves of the three-position four-way solenoid directional valve 5 and the four outrigger control valves 6 are de-energized. The rod chamber of the four outrigger cylinders 7 is locked by the "O-type" neutral position function of the three-position four-way solenoid directional valve 5. At this time, the aerial work platform enters the parking or driving state.

[0036] It should be explained that the present invention changes the traditional "O-type" center-position function three-position four-way solenoid directional valve 5 to a "Y-type" center-position function three-position four-way solenoid directional valve 5, and adds a hydraulic control check valve 8.

[0037] To facilitate understanding of the above technical solutions of the present invention, the working principle or operation method of the present invention in actual process will be described in detail below.

[0038] In practical applications, oil tank 1 stores hydraulic oil, and electric motor 2 serves as the power source. It directly connects to gear pump 3, driving the gear pump to rotate and draw hydraulic oil from the oil tank. The suction port of gear pump 3 is connected to oil tank 1 via a pipeline, while its outlet is connected in parallel to the V port of relief valve 4 and the P port of three-position four-way solenoid directional valve 5. Relief valve 4 limits the maximum system pressure, and its C port, together with the T port of directional valve 5, returns oil to oil tank 1 in parallel, achieving overpressure protection for the system.

[0039] When the aerial work platform vehicle enters the working state, the outriggers need to be extended to stabilize the vehicle. At this time, hydraulic oil flows out through gear pump 3 and enters the P port of the three-position four-way solenoid directional valve 5. The solenoid valve SV1 of the three-position four-way solenoid directional valve 5 is energized, making the P port of the three-position four-way solenoid directional valve 5 connected to the A port of the three-position four-way solenoid directional valve 5, and the B port of the three-position four-way solenoid directional valve 5 connected to the T port of the three-position four-way solenoid directional valve 5. The hydraulic oil flows out through the A port of the three-position four-way solenoid directional valve 5, enters the V3 port of the hydraulic control check valve 8, and flows out through the C3 port of the hydraulic control check valve 8 into the V1 port of the four outrigger control valves 6. At the same time, the hydraulic oil opens the hydraulic control check valve 8, making the V4 port of the hydraulic control check valve 8 connected to the C4 port of the hydraulic control check valve 8. The solenoid valves SV3 of the four outrigger control valves 6... When solenoid valves SV4, SV5, and SV6 are energized, the V1 port of the four outrigger control valves 6 connects with the C1 port of the four outrigger control valves 6. Hydraulic oil flows out through the C1 port of the four outrigger control valves 6 and enters the rodless chamber of the four outrigger cylinders 7. The hydraulic oil in the rod chamber of the four outrigger cylinders 7 returns to the oil tank 1 through the C2 and V2 ports of the four outrigger control valves 6, the C4 port and V4 port of the hydraulic control check valve 8, the B port of the three-position four-way solenoid directional valve 5, and the T port of the three-position four-way solenoid directional valve 5. At this time, the four outrigger cylinders 7 extend. After the four outrigger cylinders 7 extend, all solenoid valves of the three-position four-way solenoid directional valve 5 and the four outrigger control valves 6 are de-energized. The four outrigger control valves 6 lock the rodless chamber of the four outrigger cylinders 7, and the system enters the high-altitude operation state.

[0040] When the aerial work platform vehicle completes its work and needs to retract its outriggers to enter driving mode, hydraulic oil flows out through gear pump 3 and enters the P port of the three-position four-way solenoid valve 5. The solenoid valve SV2 of the three-position four-way solenoid valve 5 is energized, connecting the P port of the three-position four-way solenoid valve 5 with its B port, and connecting the A port of the three-position four-way solenoid valve 5 with its T port. Hydraulic oil flows out through the B port of the three-position four-way solenoid valve 5, enters the V4 port of the hydraulically controlled check valve 8, and then flows out through the C4 port of the hydraulically controlled check valve 8 into the V2 port of the four outrigger control valves 6. Simultaneously, the hydraulic oil opens the check valves of the four outrigger control valves 6, activating the solenoid valves SV3, SV4, SV5, and SV6. When valve SV6 is energized, the V1 port of the four outrigger control valves 6 is connected to the C1 port of the four outrigger control valves 6. Hydraulic oil flows out through the C2 port of the four outrigger control valves 6 and enters the rod chamber of the four outrigger cylinders 7. The hydraulic oil in the rodless chamber of the four outrigger cylinders 7 returns to the oil tank 1 through the C1 port of the four outrigger control valves 6, the V1 port of the four outrigger control valves 6, the C3 port of the hydraulic control check valve 8, the V3 port of the hydraulic control check valve 8, the A port of the three-position four-way solenoid directional valve 5, and the T port of the three-position four-way solenoid directional valve 5. At this time, the four outrigger cylinders 7 retract. After the four outrigger cylinders 7 retract, all the solenoid valves of the three-position four-way solenoid directional valve 5 and the four outrigger control valves 6 are de-energized. The hydraulic control check valve 8 locks the rod chamber of the four outrigger cylinders 7, and the vehicle enters the driving or retracting state.

[0041] When the system is in the neutral position, the three-position four-way solenoid directional valve 5 with the "Y-type" neutral function is not in operation. Ports A and B of the three-position four-way solenoid directional valve 5 are connected to port T. This ensures that when not in operation or after operation, the internal pressure oil in the pipeline connecting port A of the three-position four-way solenoid directional valve 5, ports V3 and C3 of the hydraulic check valve 8 to port V1 of the four outrigger control valves 6, and the pipeline connecting port B of the four outrigger control valves 6 to port V4 of the hydraulic check valve 8, flows through the oil tank 1, reducing the impact of the internal pressure oil on the hydraulic check valve 8. The hydraulic check valve 8 locks the rod chambers of the four outrigger cylinders 7, effectively preventing the outrigger cylinders from falling to the ground and ensuring driving safety.

[0042] In summary, by utilizing the above-mentioned technical solution of the present invention, the present invention, by setting a hydraulic control check valve 8 in the oil return path of the outrigger cylinder 7 and combining it with the Y-shaped mid-position structure of the three-position four-way solenoid directional valve 5, can achieve automatic oil circuit locking and residual pressure release when the outrigger is not in motion. This effectively avoids the phenomenon of automatic retraction or fall of the outrigger caused by factors such as excessively long parking time, vehicle travel on bumpy roads, and minor leakage of the cylinder, thereby protecting the outrigger cylinder 7, improving the overall stability of the aerial work platform and the safety of the vehicle, and extending the service life of the equipment.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A trailing leg protection system for an off-road scissor lift aerial work platform, characterized in that, include: Oil tank (1), electric motor (2), gear pump (3), overflow valve (4), three-position four-way solenoid directional valve (5), several outrigger control valves (6), several outrigger cylinders (7) and hydraulic check valve (8); Among them, the hydraulic oil tank (1) is connected to the gear pump (3) via the motor (2); the gear pump (3) is connected to the relief valve (4); the gear pump (3) is also connected to the three-position four-way solenoid directional valve (5); the three-position four-way solenoid directional valve (5) is connected to the hydraulic control check valve (8); the hydraulic control check valve (8) is connected to several outrigger control valves (6); the several outrigger control valves (6) are respectively connected to the corresponding outrigger cylinders (7); the relief valve (4) is connected to the hydraulic oil tank (1).

2. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 1, characterized in that, The oil inlet of the gear pump (3) is connected to the oil tank (1) through a pipeline. The gear pump (3) is driven to rotate by the motor (2) and draws oil from the oil tank (1).

3. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 2, characterized in that, The oil outlet of the gear pump (3) is connected in parallel to the V port of the overflow valve (4) and the P port of the three-position four-way solenoid valve (5) through a pipeline.

4. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 3, characterized in that, The C port of the overflow valve (4) and the T port of the three-position four-way solenoid directional valve (5) are connected in parallel to the return oil of the oil tank (1).

5. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 4, characterized in that, The A port of the three-position four-way solenoid directional valve (5) is connected to the V3 port of the hydraulic control check valve (8); the B port of the three-position four-way solenoid directional valve (5) is connected to the V4 port of the hydraulic control check valve (8), and the switching direction of the three-position four-way solenoid directional valve (5) is controlled by solenoid valves SV1 and SV2.

6. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 5, characterized in that, The C3 port of the hydraulic check valve (8) is connected to the V1 port of several outrigger control valves (6) via a three-way connector, and the C4 port of the hydraulic check valve (8) is connected to the V2 port of several outrigger control valves (6) via a three-way connector.

7. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 6, characterized in that, The C1 ports of the outrigger control valves (6) are respectively connected to the rodless chambers of the outrigger cylinders (7), and the C2 ports of the outrigger control valves (6) are respectively connected to the rod chambers of the outrigger cylinders (7).

8. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 7, characterized in that, The outrigger control valves (6) are controlled by solenoid valves SV3, SV4, SV5 and SV6 respectively. When the solenoid valves SV3, SV4, SV5 and SV6 are energized, the V1 port of the outrigger control valves (6) is connected to the C1 port of the outrigger control valves (6) respectively, and the V2 port of the outrigger control valves (6) is connected to the C2 port of the outrigger control valves (6).

9. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 8, characterized in that, The C3 port of the hydraulic control check valve (8) and the V3 port of the hydraulic control check valve (8) form a return oil path. This path is connected to the A port of the three-position four-way solenoid directional valve (5) and is used to conduct oil to the oil tank (1) when the outrigger cylinder (7) returns oil.

10. The outrigger protection system for an off-road scissor lift aerial work platform according to claim 9, characterized in that, When the three-position four-way solenoid directional valve (5) is in the neutral position, the A port of the three-position four-way solenoid directional valve (5) is connected to the T port of the three-position four-way solenoid directional valve (5), and the B port of the three-position four-way solenoid directional valve (5) is connected to the T port of the three-position four-way solenoid directional valve (5). The T port of the three-position four-way solenoid directional valve (5) is connected to the return oil of the oil tank (1).

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