Energy recovery system and method for support transport vehicle

Abstract

The present invention discloses an energy recovery system and method for a scaffold transporter, which belongs to the field of energy recovery technology, and includes an oil tank, a hydraulic pump, a first one-way valve, a two-position three-way electromagnetic reversing valve A, and a three-position three-way electromagnetic reversing valve A. The present invention is directed to the energy recovery system of the scaffold transporter, and proposes to use the energy released by the lifting cylinder as the power source of the variable-length cylinder, thereby realizing the effective recycling of the internal energy of the hydraulic system. This system not only improves the energy efficiency of the system, but also effectively reduces the energy consumption of the system. Secondly, by designing a solution in which two groups of hydraulic circuits share one group of energy recovery circuits, this system greatly saves the space requirements of the system and simplifies the system structure. This system adopts a two-level energy recovery strategy, which greatly improves the efficiency and stability of energy recovery, and overcomes the problems of low energy conversion efficiency and low energy recovery efficiency and large system pressure fluctuations in the traditional mode.

Description

Technical Field

[0001] The invention belongs to the technical field of energy recovery, and in particular relates to an energy recovery system and method for a support transport vehicle. Background Art

[0002] Energy recovery system is a technical system whose main function is to recover, convert and store energy that would otherwise be lost or wasted for subsequent use. This system is widely used in various fields, including automobiles, industry, electricity, etc., aiming to improve energy efficiency, reduce energy waste, and reduce negative impacts on the environment.

[0003] As the core power transmission technology in the field of industry and transportation, hydraulic systems are highly favored for their high power and high efficiency. However, traditional hydraulic systems still face challenges in energy recovery and space utilization. Existing hydraulic energy recovery technologies often face problems such as high energy loss and high system complexity. Especially in application scenarios within limited spaces, traditional hydraulic systems often require independent energy recovery devices, resulting in a large system size and complex layout. In addition, the primary energy recovery mode limits the overall energy recovery efficiency and cannot effectively meet the needs of modern industry for efficient and energy-saving systems. In order to solve the above problems, there is an urgent need for an energy recovery system and method for a scaffold transporter. Summary of the invention

[0004] The purpose of the present invention is to solve the challenges that still exist in traditional hydraulic systems in terms of energy recovery and space utilization. Existing hydraulic energy recovery technologies often face problems such as high energy loss and large system complexity. Especially in application scenarios within limited spaces, traditional hydraulic systems often require independent energy recovery devices, resulting in a large system volume and complex layout. In addition, the primary energy recovery mode limits the overall energy recovery efficiency and cannot effectively meet the needs of modern industry for efficient and energy-saving systems. A support transport vehicle energy recovery system and method are proposed.

[0005] In order to achieve the above-mentioned objectives, the present invention adopts the following technical scheme: a support transport vehicle energy recovery system, including a fuel tank, a hydraulic pump, a first one-way valve, a two-position three-way solenoid reversing valve A and a three-position three-way solenoid reversing valve A, the oil inlet and the oil outlet of the hydraulic pump are respectively connected to the fuel tank and the oil inlet of the first one-way valve, the hydraulic pump provides a power source for the entire hydraulic system, the oil outlet of the hydraulic pump is connected to the oil inlet of the first overflow valve, the oil outlet of the first overflow valve is connected to the fuel tank, and the first overflow valve ensures the system pressure to prevent the system from overloading.

[0006] As a further description of the above technical solution:

[0007] The oil outlet A of the two-position three-way solenoid reversing valve A is connected to the rodless chambers of the first lifting cylinder and the second lifting cylinder respectively through the first synchronization valve, the rod chambers of the first lifting cylinder and the second lifting cylinder are connected in series to the oil inlet of the two-position two-way solenoid reversing valve A, and the oil return port T of the two-position three-way solenoid reversing valve A is connected to the oil inlet of the two-position two-way solenoid reversing valve B through the second one-way valve.

[0008] As a further description of the above technical solution:

[0009] The oil outlet of the two-position two-way electromagnetic reversing valve B is connected to the first accumulator and the oil inlet of the second relief valve in sequence, and the oil outlet of the second relief valve is connected to the second accumulator.

[0010] As a further description of the above technical solution:

[0011] The oil inlet P and the oil outlet A of the three-position three-way electromagnetic reversing valve A are respectively connected to the second accumulator and the second synchronous valve oil inlet, and the oil outlet of the second synchronous valve is connected to the rodless chamber of the first and second luffing cylinders; the rod chambers of the first and second luffing cylinders are connected in series and connected to the oil inlet of the two-position two-way electromagnetic reversing valve C.

[0012] As a further description of the above technical solution:

[0013] The oil outlet of the two-position two-way electromagnetic reversing valve C is connected to the working oil port of the two-position three-way electromagnetic reversing valve B, and the oil inlet of the two-position three-way electromagnetic reversing valve B is connected to the second accumulator; the oil outlet T of the three-position three-way electromagnetic reversing valve A is connected to the oil tank.

[0014] This article also discloses a method for energy recovery of a support transport vehicle, which specifically includes the following steps:

[0015] S1, the lifting cylinder of the support transporter is in the rising state, the piston rod of the lifting cylinder is extended, the two-position three-way electromagnetic reversing valve A is energized and is in the left position, and the hydraulic oil passes through the first check valve, the two-position three-way electromagnetic reversing valve A, and the first synchronous valve into the rodless chamber of the lifting cylinder;

[0016] S2. When the lifting cylinder descends, the piston rod of the lifting cylinder is retracted, and the oil in the rodless chamber passes through the first synchronous valve, the right position of the two-position three-way electromagnetic reversing valve A, the second one-way valve, and the left position of the two-position two-way electromagnetic reversing valve B to enter the first accumulator, completing the first-level energy storage. When the pressure in the first accumulator is too high, the second relief valve opens to allow the oil to enter the second accumulator, completing the second-level energy storage;

[0017] S3. When the working device of the support transporter needs to swing downward, that is, the piston rod of the luffing cylinder extends, the oil in the second accumulator passes through the left position of the three-position three-way electromagnetic reversing valve A, passes through the second synchronous valve and enters the rodless chamber of the luffing cylinder, and the first accumulator releases energy to drive the luffing cylinder to work and charges the second accumulator at the same time; the oil in the rod chambers of the first and second luffing cylinders passes through the left position of the two-position two-way electromagnetic reversing valve C and the right position of the two-position three-way electromagnetic reversing valve B and enters the oil tank, and the two-position two-way electromagnetic reversing valve A is in the right position;

[0018] S4. When the working device of the support transporter needs to swing downward, that is, when the piston rods of the first and second luffing cylinders are retracted, the oil passes through the left position of the two-position three-way solenoid reversing valve B, enters the left position of the two-position two-way solenoid reversing valve C, and enters the rod chamber.

[0019] As a further description of the above technical solution:

[0020] In S1, the lifting cylinder of the support transporter is in the rising state, the piston rods of the first lifting cylinder and the second lifting cylinder are extended, the two-position three-way solenoid reversing valve A is energized in the left position, the hydraulic oil passes through the first one-way valve, the two-position three-way solenoid reversing valve A and the first synchronization valve into the rodless cavity of the first lifting cylinder and the second lifting cylinder; the rod cavity of the first lifting cylinder and the second lifting cylinder is connected in series, the hydraulic oil passes through the left position of the two-position two-way solenoid reversing valve A and the right position of the two-position three-way solenoid reversing valve B into the oil tank, and the support transporter completes the lifting task.

[0021] As a further description of the above technical solution:

[0022] In S2, when the lifting cylinder descends, the lifting cylinder piston rod is retracted, and the oil in the rodless chamber passes through the first synchronous valve, the right position of the two-position three-way electromagnetic reversing valve A, the second one-way valve, and the left position of the two-position two-way electromagnetic reversing valve B to enter the first accumulator, completing the first-level energy storage. When the pressure in the first accumulator is too large, the second overflow valve is opened to allow the oil to enter the second accumulator to complete the second-level energy storage. The three-position three-way electromagnetic reversing valve A is in the middle position; due to the downward pressure of the piston rod under the gravity, the rod chambers of the first lifting cylinder and the second lifting cylinder generate back pressure, so that the hydraulic oil in the oil tank enters the rod chamber through the right position of the two-position three-way electromagnetic reversing valve B and the left position of the two-position two-way electromagnetic reversing valve A, and the two-position two-way electromagnetic reversing valve C is in the right position, and the energy recovery process is completed. The lifting cylinder piston rod retraction process is pressed down by the weight and the descending process is faster. The use of secondary energy recovery allows the gravitational potential energy to be converted into hydraulic energy to the greatest extent to achieve energy recovery.

[0023] As a further description of the above technical solution:

[0024] In S3, when the working device of the support transporter needs to swing downward, that is, the piston rod of the boom cylinder extends, the pressure of the second overflow valve is adjusted, the second overflow valve is opened, the first accumulator releases energy, and the hydraulic fluid overflows through the second overflow valve, passes through the right position of the three-position three-way electromagnetic reversing valve A, and enters the rodless chamber of the first boom cylinder and the second boom cylinder through the second synchronization valve. The first accumulator releases energy to drive the boom cylinder to work and charges the second accumulator at the same time; the rod chamber of the first boom cylinder and the second boom cylinder are connected in series, and the oil enters the oil tank through the left position of the two-position two-way electromagnetic reversing valve C and the right position of the two-position three-way electromagnetic reversing valve B, and the two-position two-way electromagnetic reversing valve A is in the right position; when the boom length is completed, the three-position three-way electromagnetic reversing valve A is in the middle position, and the two-position two-way electromagnetic reversing valve C is in the right position, thereby realizing the position adjustment of the hydraulic cylinder.

[0025] As a further description of the above technical solution:

[0026] In S4, when the piston rod of the luffing cylinder is retracted, the second accumulator releases energy so that the hydraulic oil passes through the left position of the two-position three-way solenoid reversing valve B, enters the left position of the two-position two-way solenoid reversing valve C, and enters the rod chambers of the first luffing cylinder and the second luffing cylinder. The oil in the rodless chambers of the first luffing cylinder and the second luffing cylinder passes through the second synchronization valve and enters the right position of the three-position three-way solenoid reversing valve A and enters the oil tank to complete the luffing action. The energy stored in the first accumulator and the second accumulator is used to complete the luffing action of the luffing cylinder, thereby realizing the effective recycling of energy inside the hydraulic system.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] In the present invention, for the energy recovery system of the support transporter, it is proposed to use the energy released by the lifting cylinder as the power source of the variable-length cylinder, thereby realizing the effective recycling of energy inside the hydraulic system. This system not only improves the energy efficiency of the system, but also effectively reduces the energy consumption of the system. Secondly, by designing a solution in which two groups of hydraulic circuits share a group of energy recovery lines, this system greatly saves the space requirements of the system, simplifies the system structure, and reduces the overall cost and maintenance difficulty. The adoption of a two-level energy recovery strategy greatly improves the efficiency and stability of energy recovery, overcomes the problems of low energy conversion efficiency and low energy recovery efficiency and large system pressure fluctuations in the traditional mode, and not only improves the overall performance of the system, but also promotes the application and progress of hydraulic technology in energy conservation and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a structural schematic diagram of an energy recovery system for a support transport vehicle.

[0030] Legend:

[0031] Oil tank; 2. Generator; 3. Hydraulic pump; 4. First non-return valve; 5. First overflow valve; 6. Two-position three-way solenoid directional valve A; 7. First synchronization valve; 8. First lifting cylinder; 9. Second lifting cylinder; 10. Two-position two-way solenoid directional valve A; 11. Second non-return valve; 12. Two-position two-way solenoid directional valve B; 13. First accumulator; 14. Second overflow valve; 15. Two-position three-way solenoid directional valve B; 16. Second accumulator; 17. Three-position three-way solenoid directional valve A; 18. Second synchronization valve; 19. First boom cylinder; 20. Second boom cylinder; 21. Two-position two-way solenoid directional valve C. DETAILED DESCRIPTION

[0032] 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.

[0033] See also Figure 1 The present invention provides a technical solution: a support transport vehicle energy recovery system, including a fuel tank 1, a generator 2, a hydraulic pump 3, a first non-return valve 4, a two-position three-way electromagnetic reversing valve A6 and a three-position three-way electromagnetic reversing valve A17, the oil inlet and the oil outlet of the hydraulic pump 3 are respectively connected to the fuel tank 1 and the oil inlet of the first non-return valve 4, the hydraulic pump 3 provides a power source for the entire hydraulic system, the oil outlet of the hydraulic pump 3 is connected to the oil inlet of the first overflow valve 5, the oil outlet of the first overflow valve 5 is connected to the fuel tank 1, and the first overflow valve 5 ensures the system pressure to prevent the system from overloading.

[0034] The oil outlet A of the two-position three-way solenoid reversing valve A6 is connected to the rodless chambers of the first lifting cylinder 8 and the second lifting cylinder 9 respectively through the first synchronization valve 7, the rod chambers of the first lifting cylinder 8 and the second lifting cylinder 9 are connected in series to the oil inlet of the two-position two-way solenoid reversing valve A10, the oil return port T of the two-position three-way solenoid reversing valve A6 is connected to the oil inlet of the two-position two-way solenoid reversing valve B12 through the second check valve 11, the oil outlet of the two-position two-way solenoid reversing valve B12 is connected to the oil inlet of the first accumulator 13 and the second relief valve 14 in sequence, the oil outlet of the second relief valve 14 is connected to the oil inlet of the second ... The oil inlet P and the oil outlet A of the three-position three-way solenoid reversing valve A17 are respectively connected to the second accumulator 16 and the oil inlet of the second synchronous valve 18, and the oil outlet of the second synchronous valve 18 is connected to the rodless cavity of the first luffing cylinder 19 and the second luffing cylinder 20; the rod cavity of the first luffing cylinder 19 and the second luffing cylinder 20 are connected in series and are connected to the oil inlet of the two-position two-way solenoid reversing valve C21, and the oil outlet of the two-position two-way solenoid reversing valve C21 is connected to the oil inlet of the two-position three-way solenoid reversing valve B15; the oil outlet T of the three-position three-way solenoid reversing valve A17 is connected to the oil tank 1.

[0035] This article also discloses a method for energy recovery of a support transport vehicle, which specifically includes the following steps:

[0036] S1, the lifting cylinder of the support transporter is in the rising state, the piston rods of the first lifting cylinder 8 and the second lifting cylinder 9 are extended, the two-position three-way electromagnetic reversing valve A6 is energized in the left position, and the hydraulic oil passes through the first non-return valve 4, the two-position three-way electromagnetic reversing valve A6, and the first synchronous valve 7 to enter the rodless cavity of the first lifting cylinder 8 and the second lifting cylinder 9; the rod cavity of the first lifting cylinder 8 and the second lifting cylinder 9 is connected in series, and the hydraulic oil passes through the two-position two-way electromagnetic reversing valve A10 in the left position and the two-position three-way electromagnetic reversing valve B15 in the right position to enter the oil tank, and the support transporter completes the lifting task;

[0037] S2, when the lifting cylinder descends, the lifting cylinder piston rod is retracted, and the oil in the rodless chamber passes through the first synchronous valve 7, the right position of the two-position three-way electromagnetic reversing valve A6, the second one-way valve 11, and the left position of the two-position two-way electromagnetic reversing valve B12 to enter the first accumulator 13, completing the first-level energy storage. When the pressure of the first accumulator 13 is too large, the second overflow valve 14 opens, allowing the oil to enter the second accumulator 16, completing the second-level energy storage, and the three-position three-way electromagnetic reversing valve A17 is in the middle position; due to the downward pressure of gravity The piston rod is retracted, so that the rod chambers of the first lifting oil cylinder 8 and the second lifting oil cylinder 9 generate back pressure, so that the hydraulic oil in the oil tank 1 enters the rod chamber through the right position of the two-position three-way electromagnetic reversing valve B15 and the left position of the two-position two-way electromagnetic reversing valve A10. The two-position two-way electromagnetic reversing valve C21 is in the right position, and the energy recovery process is completed. The lifting oil cylinder piston rod is retracted during the downward pressure of the weight and the downward process is fast. The use of secondary energy recovery allows the gravitational potential energy to be converted into hydraulic energy to the greatest extent to achieve energy recovery;

[0038] S3. When the working device of the support transporter needs to swing downward, that is, the piston rod of the luffing cylinder extends, the pressure of the second relief valve 14 is adjusted, the second relief valve 14 is opened, the first accumulator 13 releases energy, and the hydraulic fluid overflows through the second relief valve 14, passes through the left position of the three-position three-way electromagnetic reversing valve A17, passes through the second synchronization valve 18 and enters the rodless chamber of the first luffing cylinder 19 and the second luffing cylinder 20, and the first accumulator 13 releases energy to drive the luffing cylinder to work, and charges the second accumulator 16 at the same time; the first luffing cylinder 19 and the rod chamber of the second luffing cylinder 20 are connected in series, and the oil enters the oil tank 1 through the left position of the two-position two-way electromagnetic reversing valve C21 and the right position of the two-position three-way electromagnetic reversing valve B15, and the two-position two-way electromagnetic reversing valve A10 is in the right position; when the luffing is completed, the three-position three-way electromagnetic reversing valve A17 is in the middle position, and the two-position two-way electromagnetic reversing valve C21 is in the right position, so as to realize the position adjustment of the hydraulic cylinder;

[0039] S4. When the piston rod of the luffing cylinder is retracted, the second accumulator 16 releases energy so that the hydraulic oil passes through the left position of the two-position three-way solenoid reversing valve B15, enters the left position of the two-position two-way solenoid reversing valve C21, and enters the rod chamber of the first luffing cylinder 19 and the second luffing cylinder 20. The oil in the rodless chamber of the first luffing cylinder 19 and the second luffing cylinder 20 passes through the second synchronization valve 18 and enters the right position of the three-position three-way solenoid reversing valve A17 and enters the oil tank to complete the luffing action. The energy stored in the first accumulator 13 and the second accumulator 16 is used to complete the luffing action of the luffing cylinder, thereby realizing the effective recycling of energy inside the hydraulic system.

[0040] In this embodiment, for the energy recovery system of the support transporter, it is proposed to use the energy released by the lifting cylinder as the power source of the variable-length cylinder, thereby realizing the effective recycling of energy inside the hydraulic system. This system not only improves the energy efficiency of the system, but also effectively reduces the energy consumption of the system. Secondly, by designing a solution in which two sets of hydraulic circuits share a set of energy recovery lines, this system greatly saves the space requirements of the system, simplifies the system structure, and reduces the overall cost and maintenance difficulty. The adoption of a two-level energy recovery strategy greatly improves the efficiency and stability of energy recovery, overcomes the problems of low energy conversion efficiency and low energy recovery efficiency and large system pressure fluctuations in the traditional mode, and not only improves the overall performance of the system, but also promotes the application and progress of hydraulic technology in energy conservation and environmental protection.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A support transport vehicle energy recovery system, comprising a fuel tank (1), a generator (2), a hydraulic pump (3), a first non-return valve (4), a two-position three-way electromagnetic reversing valve A (6) and a three-position three-way electromagnetic reversing valve A (17), characterized in that: The oil inlet and the oil outlet of the hydraulic pump (3) are connected to the oil tank (1) and the oil inlet of the first check valve (4) respectively. The hydraulic pump (3) provides a power source for the entire hydraulic system. The oil outlet of the hydraulic pump (3) is connected to the oil inlet of the first overflow valve (5). The oil outlet of the first overflow valve (5) is connected to the oil tank (1). The first overflow valve (5) ensures the system pressure to prevent the system from overloading. The oil outlet A of the two-position three-way electromagnetic reversing valve A (6) passes through the first check valve (4). A synchronous valve (7) is connected to the rodless chambers of the first lifting cylinder (8) and the second lifting cylinder (9), respectively. The rod chambers of the first lifting cylinder (8) and the second lifting cylinder (9) are connected in series to the oil inlet of the two-position two-way electromagnetic reversing valve A (10). The oil return port T of the two-position three-way electromagnetic reversing valve A (6) is connected to the oil inlet of the two-position two-way electromagnetic reversing valve B (12) through the second check valve (11). The oil outlet of the two-position two-way electromagnetic reversing valve B (12) is connected to the oil outlet of the two-position two-way electromagnetic reversing valve B (12). The oil inlet of the first accumulator (13) and the second relief valve (14) are connected in sequence, the oil outlet of the second relief valve (14) is connected to the second accumulator (16), the oil inlet P and the oil outlet A of the three-position three-way electromagnetic reversing valve A (17) are connected to the oil inlet of the second accumulator (16) and the second synchronization valve (18) respectively, and the oil outlet of the second synchronization valve (18) is connected to the rodless chamber of the first luffing cylinder (19) and the second luffing cylinder (20); The first luffing cylinder (19) and the second luffing cylinder (20) have rod chambers connected in series and connected to an oil inlet of a two-position two-way electromagnetic reversing valve C (21); an oil outlet of the two-position two-way electromagnetic reversing valve C (21) is connected to a working oil port of a two-position three-way electromagnetic reversing valve B (15); an oil inlet of the two-position three-way electromagnetic reversing valve B (15) is connected to a second accumulator (16); and an oil outlet T of the three-position three-way electromagnetic reversing valve A (17) is connected to an oil tank (1).

2. A method for energy recovery of a support transport vehicle, characterized in that: The specific steps include: S1, the lifting cylinder of the support transport vehicle is in the ascending state, the piston rod of the lifting cylinder is extended, the two-position three-way electromagnetic reversing valve A (6) is energized and is in the left position, and the hydraulic oil passes through the first non-return valve (4), the two-position three-way electromagnetic reversing valve A (6), and the first synchronous valve (7) and enters the rodless chamber of the lifting cylinder; S2, when the lifting cylinder descends, the piston rod of the lifting cylinder is retracted, and the oil in the rodless chamber passes through the first synchronous valve (7), the right position of the two-position three-way electromagnetic reversing valve A (6), the second check valve (11), and the left position of the two-position two-way electromagnetic reversing valve B (12) to enter the first accumulator (13), completing the first-stage energy storage. When the pressure in the first accumulator (13) is too high, the second relief valve (14) opens to allow the oil to enter the second accumulator (16), completing the second-stage energy storage; S3. When the working device of the support transporter needs to swing downward, that is, the piston rod of the boom cylinder extends, the oil in the second accumulator (16) passes through the left position of the three-position three-way electromagnetic reversing valve A (17), passes through the second synchronous valve (18) and enters the rodless chamber of the boom cylinder. The first accumulator (13) releases energy to drive the boom cylinder to work and charges the second accumulator (16) at the same time. The oil in the rod chambers of the first boom cylinder (19) and the second boom cylinder (20) passes through the left position of the two-position two-way electromagnetic reversing valve C (21) and the right position of the two-position three-way electromagnetic reversing valve B (15) and enters the oil tank. The two-position two-way electromagnetic reversing valve A (10) is in the right position. S4. When the working device of the support transporter needs to swing downward, that is, when the piston rods of the first luffing cylinder (19) and the second luffing cylinder (20) are retracted, the oil passes through the left position of the two-position three-way solenoid reversing valve B (15), enters the left position of the two-position two-way solenoid reversing valve C (21), and enters the rod chamber.

3. The energy recovery method of a support transport vehicle according to claim 2, characterized in that: In S1, the lifting cylinder of the support transport vehicle is in the ascending state, the piston rods of the first lifting cylinder (8) and the second lifting cylinder (9) are extended, the two-position three-way electromagnetic reversing valve A (6) is energized and is in the left position, the hydraulic oil passes through the first non-return valve (4), the two-position three-way electromagnetic reversing valve A (6), and the first synchronous valve (7) into the rodless chamber of the first lifting cylinder (8) and the second lifting cylinder (9); the rod chambers of the first lifting cylinder (8) and the second lifting cylinder (9) are connected in series, the hydraulic oil passes through the two-position two-way electromagnetic reversing valve A (10) in the left position and the two-position three-way electromagnetic reversing valve B (15) in the right position into the oil tank, and the support transport vehicle completes the lifting task.

4. The energy recovery method of a support transport vehicle according to claim 3, characterized in that: In S2, when the lifting cylinder descends, the lifting cylinder piston rod is retracted, and the oil in the rodless chamber passes through the first synchronous valve (7), the right position of the two-position three-way electromagnetic reversing valve A (6), the second one-way valve (11), and the left position of the two-position two-way electromagnetic reversing valve B (12) to enter the first accumulator (13), completing the first-stage energy storage. When the pressure in the first accumulator (13) is too high, the second relief valve (14) opens to allow the oil to enter the second accumulator (16), completing the second-stage energy storage. The three-position three-way electromagnetic reversing valve A (17) is in the middle position. The piston rod is retracted under the pressure of gravity, so that the rod chambers of the first lifting cylinder (8) and the second lifting cylinder (9) generate back pressure, so that the hydraulic oil in the oil tank (1) enters the rod chamber through the right position of the two-position three-way electromagnetic reversing valve B (15) and the left position of the two-position two-way electromagnetic reversing valve A (10). The two-position two-way electromagnetic reversing valve C (21) is in the right position, and the energy recovery process is completed. The lifting cylinder piston rod is retracted during the downward pressure of the weight and the downward process is fast. The use of secondary energy recovery allows the gravitational potential energy to be converted into hydraulic energy to the greatest extent to achieve energy recovery.

5. The energy recovery method of a support transport vehicle according to claim 4, characterized in that: In S3, when the working device of the support transport vehicle needs to swing downward, that is, the piston rod of the luffing oil cylinder extends, the pressure of the second overflow valve (14) is adjusted, the second overflow valve (14) is opened, the first accumulator (13) releases energy, the hydraulic fluid overflows through the second overflow valve (14), passes through the three-position three-way electromagnetic reversing valve A (17) to the right position, passes through the second synchronization valve (18) and enters the rodless chamber of the first luffing oil cylinder (19) and the second luffing oil cylinder (20), and the first accumulator (13) releases energy to drive the luffing oil cylinder (20). The boom cylinder works and charges the second accumulator (16) at the same time; the rod chambers of the first boom cylinder (19) and the second boom cylinder (20) are connected in series, and the oil enters the oil tank through the left position of the two-position two-way electromagnetic reversing valve C (21) and the right position of the two-position three-way electromagnetic reversing valve B (15), and the two-position two-way electromagnetic reversing valve A (10) is in the right position; when the boom is changed, the three-position three-way electromagnetic reversing valve A (17) is in the middle position, and the two-position two-way electromagnetic reversing valve C (21) is in the right position, thereby realizing the position adjustment of the hydraulic cylinder.

6. The energy recovery method of a support transport vehicle according to claim 5, characterized in that: In the above-mentioned S4, when the piston rod of the luffing oil cylinder is retracted, the second accumulator (16) releases energy so that the hydraulic oil passes through the left position of the two-position three-way electromagnetic reversing valve B (15), enters the left position of the two-position two-way electromagnetic reversing valve C (21), and enters the rod chambers of the first luffing oil cylinder (19) and the second luffing oil cylinder (20). The oil in the rodless chambers of the first luffing oil cylinder (19) and the second luffing oil cylinder (20) passes through the second synchronization valve (18) and enters the right position of the three-position three-way electromagnetic reversing valve A (17) and enters the oil tank, completing the luffing action. The energy stored in the first accumulator (13) and the second accumulator (16) is used to complete the luffing action of the luffing oil cylinder, thereby realizing the effective recycling of energy inside the hydraulic system.

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