Forklift and auxiliary driving system for graded recovery of hydraulic pressure thereof
By designing the auxiliary driving system for the hydraulic recovery of forklifts, the parallel placement of hydraulic accumulators and the solenoid valves cooperate to achieve maximum recovery of forklift energy, solving the problems of high energy consumption and low energy utilization of traditional forklifts, and improving the energy efficiency and contribution of green development of forklifts.
Patent Information
- Application Number
- CN202421867320.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-04-29
- Estimated Expiration
- 2034-08-05
AI Technical Summary
Traditional forklift lifting systems have problems such as high energy consumption and insufficient energy utilization, which leads to increased hydraulic oil temperature and reduced viscosity, which may cause leakage, vibration and stability problems.
An auxiliary driving system for grading hydraulic recovery for forklifts is designed, including a hydraulic oil tank, a hydraulic pump, a motor, multiple hydraulic accumulators and solenoid valves. By placing hydraulic accumulators in parallel and coordinating actions, the potential energy of heavy objects at different pressures is recovered to maximize the energy recovery.
It effectively solves the problems of high energy consumption and low energy utilization of traditional forklift lifting systems, achieves maximum energy recovery, improves the energy efficiency of forklifts, and contributes to the green development of the logistics industry.
Smart Images
Figure CN222809198U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of forklift driving, in particular to a forklift and an auxiliary driving system of the forklift for graded recovery of hydraulic pressure. Background Art
[0002] As the core handling tool in the field of logistics and warehousing, forklifts are becoming increasingly important with the booming development of the logistics industry. However, during the operation of forklifts, some key issues need to be solved urgently.
[0003] The lifting movement of a forklift is the core function of its operation. Take a stacking forklift as an example. During the lifting process, the motor drives the hydraulic pump to deliver hydraulic oil to the oil system to lift the heavy object. In this process, the hydraulic energy is converted into the potential energy of the heavy object. However, when the forklift descends, the potential energy of the heavy object is often converted into kinetic energy when the heavy object descends, or converted into heat at the hydraulic control valve and carried away by the hydraulic oil. This causes the hydraulic oil temperature to rise and the viscosity to decrease, which may cause leakage, vibration, and even affect the stability of the forklift.
[0004] Traditional forklift lifting systems face the problems of high energy consumption and insufficient energy utilization, which have not been effectively solved so far. Therefore, exploring forklift potential energy recovery technology not only has broad market application prospects, but also has huge economic benefits. In addition, this technology also has far-reaching significance for promoting environmental protection and energy conservation. By innovating the energy recovery mechanism of forklifts, we can not only improve the energy efficiency of forklifts, but also contribute to the green development of the logistics industry.
[0005] In view of this, the applicant filed this application after studying the existing technology. Utility Model Content
[0006] The utility model provides a forklift and an auxiliary driving system of the graded recovery hydraulic pressure thereof, aiming to improve at least one of the above technical problems.
[0007] In order to solve the above technical problems, the utility model provides a forklift's graded recovery hydraulic auxiliary drive system, which includes a hydraulic oil tank, a hydraulic pump, an electric motor, a three-position three-way solenoid valve, a hydraulic oil cylinder, a first two-position two-way solenoid valve, a first hydraulic accumulator, a second two-position two-way solenoid valve, a second hydraulic accumulator, a third two-position two-way solenoid valve, and a fourth two-position two-way solenoid valve. The hydraulic oil cylinder is used to drive the forklift's cargo fork to move up and down.
[0008] The output shaft of the motor is connected to the hydraulic pump for driving the hydraulic pump to work. The oil inlet pipeline of the hydraulic pump is connected to the hydraulic oil tank. The oil outlet pipeline of the hydraulic pump is connected to the oil inlet of the three-position three-way solenoid valve. The oil outlet pipeline of the three-position three-way solenoid valve is connected to the rodless chamber of the hydraulic cylinder. The oil return pipeline of the three-position three-way solenoid valve is connected to the first working interface of the first two-position two-way solenoid valve, the second two-position two-way solenoid valve and the third two-position two-way solenoid valve. The second working interface pipeline of the first two-position two-way solenoid valve is connected to the first hydraulic accumulator. The second working interface pipeline of the second two-position two-way solenoid valve is connected to the second hydraulic accumulator. The second working interface pipeline of the third two-position two-way solenoid valve is connected to the hydraulic oil tank. The first working interface pipeline of the fourth two-position two-way solenoid valve is connected to the first working interface of the first two-position two-way solenoid valve, the second two-position two-way solenoid valve and the third two-position two-way solenoid valve. The second working interface pipeline of the fourth two-position two-way solenoid valve is connected to the rodless chamber of the hydraulic cylinder.
[0009] The first two-position two-way solenoid valve, the second two-position two-way solenoid valve and the third two-position two-way solenoid valve are all structures without exhaust ports. The oil outlet of the three-position three-way solenoid valve is configured to be switchably connected or disconnected with the oil inlet and the oil return port. The pressure of the first hydraulic accumulator is not greater than the pressure of the second hydraulic accumulator.
[0010] As a further solution of the utility model, the auxiliary drive system for graded hydraulic recovery of a forklift further includes a first overflow valve and a first check valve.
[0011] The oil inlet pipeline of the first one-way valve is connected to the oil outlet of the hydraulic pump. The oil outlet pipeline of the first one-way valve is connected to the oil inlet of the three-position three-way solenoid valve. The oil inlet pipeline of the first overflow valve is connected to the oil outlet of the hydraulic pump. The oil outlet pipeline of the first overflow valve is connected to the hydraulic oil tank.
[0012] As a further solution of the utility model, the auxiliary driving system for graded hydraulic recovery of a forklift further comprises a throttle valve. The throttle valve pipeline is connected between the oil outlet of the three-position three-way solenoid valve and the rodless chamber of the hydraulic cylinder.
[0013] The auxiliary driving system of the forklift with graded hydraulic recovery has two hydraulic cylinders, wherein the two hydraulic cylinders are respectively a first hydraulic cylinder and a second hydraulic cylinder, and the first hydraulic cylinder and the second hydraulic cylinder are connected in parallel.
[0014] As a further solution of the utility model, the auxiliary drive system for graded hydraulic recovery of a forklift further comprises a second one-way valve. The oil inlet pipeline of the second one-way valve is connected to the oil return port of the three-position three-way solenoid valve. The oil outlet pipeline of the second one-way valve is connected to the first working interface of the first two-position two-way solenoid valve, the second two-position two-way solenoid valve and the third two-position two-way solenoid valve.
[0015] As a further solution of the utility model, the auxiliary drive system for graded hydraulic recovery of a forklift further comprises a second relief valve and a third relief valve. The oil inlet of the second relief valve is connected to the first hydraulic accumulator. The oil inlet of the third relief valve is connected to the second hydraulic accumulator. The oil outlets of the second relief valve and the third relief valve are connected to the hydraulic oil tank.
[0016] As a further solution of the utility model, the auxiliary drive system for graded hydraulic recovery of a forklift further comprises a third one-way valve. The oil inlet pipeline of the third one-way valve is connected to the first working interface of the first two-position two-way solenoid valve and the second two-position two-way solenoid valve. The oil outlet pipeline of the third one-way valve is connected between the oil outlet of the three-position three-way solenoid valve and the throttle valve.
[0017] The present application further provides a forklift, which comprises an auxiliary drive system for graded hydraulic recovery of a forklift as described in any paragraph of the first aspect.
[0018] By adopting the above technical solution, the utility model can achieve the following technical effects:
[0019] The utility model discloses a forklift's graded recovery hydraulic auxiliary drive system that relies on an electric motor to drive the lifting movement. A plurality of hydraulic accumulators are placed in parallel and cooperate with each other to recover the potential energy of heavy objects with different pressures, thereby realizing maximum energy recovery and having good practical significance. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the specific implementation methods of the present invention, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain implementation methods of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0021] Figure 1 The present invention is a structural diagram of a graded recovery hydraulic auxiliary drive system of a forklift.
[0022] Figure 2 The invention discloses a logic block diagram of a control method of a graded recovery hydraulic auxiliary drive system of a forklift.
[0023] Markings in the figure: 1-hydraulic oil tank, 2-hydraulic pump, 3-motor, 4-first overflow valve, 5-first non-return valve, 6-three-position three-way solenoid valve, 7-throttle valve, 8-first hydraulic cylinder, 9-second hydraulic cylinder, 10-second non-return valve, 11-first two-position two-way solenoid valve, 12-first hydraulic accumulator (low pressure), 13-second overflow valve, 14-second two-position two-way solenoid valve, 15-second hydraulic accumulator (high pressure), 16-third overflow valve, 17-third two-position two-way solenoid valve, 18-fourth two-position two-way solenoid valve, 19-third non-return valve. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical scheme and advantages of the implementation mode of the utility model clearer, the technical scheme in the implementation mode of the utility model will be clearly and completely described below in conjunction with the drawings in the implementation mode of the utility model. Obviously, the described implementation mode is a part of the implementation mode of the utility model, not all of the implementation modes. Based on the implementation mode in the utility model, all other implementation modes obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model. Therefore, the following detailed description of the implementation mode of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected implementation mode of the utility model. Based on the implementation mode in the utility model, all other implementation modes obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.
[0025] Embodiment 1: Figure 1 and Figure 2 As shown, the embodiment of the utility model provides a forklift's graded hydraulic recovery auxiliary drive system, which includes a hydraulic oil tank 1, a hydraulic pump 2, an electric motor 3, a three-position three-way solenoid valve 6, a hydraulic cylinder, a first two-position two-way solenoid valve 11, a first hydraulic accumulator 12, a second two-position two-way solenoid valve 14, a second hydraulic accumulator 15, a third two-position two-way solenoid valve 17, and a fourth two-position two-way solenoid valve 18. The hydraulic cylinder is used to drive the forklift's fork to move up and down.
[0026] The output shaft of the motor 3 is connected to the hydraulic pump 2 for driving the hydraulic pump 2 to work. The oil inlet pipeline of the hydraulic pump 2 is connected to the hydraulic oil tank 1. The oil outlet pipeline of the hydraulic pump 2 is connected to the oil inlet of the three-position three-way solenoid valve 6. The oil outlet pipeline of the three-position three-way solenoid valve 6 is connected to the rodless chamber of the hydraulic cylinder. The oil return pipeline of the three-position three-way solenoid valve 6 is connected to the first working interface of the first two-position two-way solenoid valve 11, the second two-position two-way solenoid valve 14 and the third two-position two-way solenoid valve 17. The second working interface pipeline of the first two-position two-way solenoid valve 11 is connected to the first hydraulic accumulator 12. The second working interface pipeline of the second two-position two-way solenoid valve 14 is connected to the second hydraulic accumulator 15. The second working interface pipeline of the third two-position two-way solenoid valve 17 is connected to the hydraulic oil tank 1. The first working interface pipeline of the fourth 2-position 2-way solenoid valve 18 is connected to the first working interfaces of the first 2-position 2-way solenoid valve 11, the second 2-position 2-way solenoid valve 14 and the third 2-position 2-way solenoid valve 17. The second working interface pipeline of the fourth 2-position 2-way solenoid valve 18 is connected to the rodless chamber of the hydraulic cylinder.
[0027] The first two-position two-way solenoid valve 11, the second two-position two-way solenoid valve 14 and the third two-position two-way solenoid valve 17 are all structures without exhaust ports. The oil outlet of the three-position three-way solenoid valve 6 is configured to be switchable to be connected or disconnected with the oil inlet and the oil return port. The pressure of the first hydraulic accumulator 12 is not greater than the pressure of the second hydraulic accumulator 15.
[0028] Specifically, when the first control terminal a of the three-position three-way solenoid valve 6 is energized, the oil outlet and the oil return port of the three-position three-way solenoid valve 6 are connected. When the second control terminal b of the three-position three-way solenoid valve 6 is energized, the oil inlet and the oil outlet of the three-position three-way solenoid valve 6 are connected. When the third control terminal c of the fourth two-position two-way solenoid valve 18 is energized, the fourth two-position two-way solenoid valve 18 is connected. When the fourth control terminal d of the first two-position two-way solenoid valve 11 is energized, the first two-position two-way solenoid valve 11 is connected. When the fifth control terminal e of the second two-position two-way solenoid valve 14 is energized, the second two-position two-way solenoid valve 14 is connected. When the sixth control terminal f of the third two-position two-way solenoid valve 17 is energized, the third two-position two-way solenoid valve 17 is connected. When the control end of the solenoid valve is powered off, the three-position three-way solenoid valve 6, the first two-position two-way solenoid valve 11, the second two-position two-way solenoid valve 14, the third two-position two-way solenoid valve 17 and the fourth two-position two-way solenoid valve 18 are all in an open state.
[0029] The utility model discloses a forklift's graded hydraulic recovery auxiliary drive system that relies on a motor 3 to drive the lifting movement, and multiple hydraulic accumulators are placed in parallel to cooperate in the recovery of heavy object potential energy of different pressures to maximize energy recovery. The utility model discloses a forklift's graded hydraulic recovery auxiliary drive system that is particularly suitable for energy-saving and emission-reduction forklifts, especially for electric-hydraulic composite forklifts.
[0030] The utility model relates to a forklift's graded recovery hydraulic auxiliary drive system, which uses multiple hydraulic accumulators to work together to avoid throttling and overflow losses, greatly improves energy utilization, and effectively solves the problems of high energy consumption and low energy utilization in traditional forklift lifting systems.
[0031] During the release of the hydraulic accumulator, the motor 3 can stop working, and the hydraulic accumulator directly drives the lifting movement. The motor 3 can also work at the same time, and the hydraulic pump 2 and the hydraulic accumulator provide hydraulic oil at the same time to speed up the lifting speed.
[0032] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 1 As shown, the auxiliary drive system for graded hydraulic recovery of a forklift also includes a first overflow valve 4 and a first non-return valve 5. The oil inlet pipeline of the first non-return valve 5 is connected to the oil outlet of the hydraulic pump 2. The oil outlet pipeline of the first non-return valve 5 is connected to the oil inlet of the three-position three-way solenoid valve 6. The oil inlet pipeline of the first overflow valve 4 is connected to the oil outlet of the hydraulic pump 2. The oil outlet pipeline of the first overflow valve 4 is connected to the hydraulic oil tank 1.
[0033] Specifically, the first overflow valve 4 can prevent the pressure at the oil outlet of the hydraulic pump 2 from being too high, thereby preventing the hydraulic pump 2 from being damaged. The first check valve 5 can prevent the hydraulic oil from reversely impacting the hydraulic pump 2 when the pressure at the hydraulic cylinder is greater than the pressure at the oil outlet of the hydraulic pump 2, thereby preventing the hydraulic pump 2 from being damaged, thereby greatly improving the safety and service life of the entire system, and having great practical significance.
[0034] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 1 As shown, the auxiliary drive system for graded hydraulic recovery of a forklift also includes a throttle valve 7. The throttle valve 7 pipeline is connected between the oil outlet of the three-position three-way solenoid valve 6 and the rodless chamber of the hydraulic cylinder. The number of hydraulic cylinders in the auxiliary drive system for graded hydraulic recovery of a forklift is two. Among them, the two hydraulic cylinders are respectively a first hydraulic cylinder 8 and a second hydraulic cylinder 9. The first hydraulic cylinder 8 and the second hydraulic cylinder 9 are connected in parallel.
[0035] Specifically, the movement speed of the hydraulic cylinder can be adjusted through the throttle valve 7 to avoid impact on the load, fork or hydraulic cylinder due to excessive speed, thereby ensuring the stability of the hydraulic system.
[0036] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 1 As shown, the auxiliary drive system for graded hydraulic recovery of a forklift further comprises a second one-way valve 10. The oil inlet pipeline of the second one-way valve 10 is connected to the oil return port of the three-position three-way solenoid valve 6. The oil outlet pipeline of the second one-way valve 10 is connected to the first working interface of the first two-position two-way solenoid valve 11, the second two-position two-way solenoid valve 14 and the third two-position two-way solenoid valve 17. Preferably, the auxiliary drive system for graded hydraulic recovery of a forklift further comprises a second overflow valve 13 and a third overflow valve 16. The oil inlet of the second overflow valve 13 is connected to the first hydraulic accumulator 12. The oil inlet of the third overflow valve 16 is connected to the second hydraulic accumulator 15. The oil outlets of the second overflow valve 13 and the third overflow valve 16 are connected to the hydraulic oil tank 1.
[0037] Specifically, the second one-way valve 10 can prevent the hydraulic oil of the energy storage system from being reversely input into the hydraulic cylinder in the cargo lowering device to cause impact. The second relief valve 13 and the third relief valve 16 can prevent the pressure of the hydraulic accumulator from being too high, ensuring the stable operation of the entire hydraulic system.
[0038] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 1 As shown, the auxiliary drive system for graded hydraulic recovery of a forklift further comprises a third one-way valve 19. The oil inlet pipeline of the third one-way valve 19 is connected to the first working interface of the first two-position two-way solenoid valve 11 and the second two-position two-way solenoid valve 14. The oil outlet pipeline of the third one-way valve 19 is connected between the oil outlet of the three-position three-way solenoid valve 6 and the throttle valve 7. Specifically, through the third one-way valve 19, it is possible to effectively prevent the hydraulic oil of the hydraulic cylinder from flowing to the hydraulic accumulator during the extension period, thereby preventing the problem that the fork cannot be raised or the raising speed is slow, which has good practical significance.
[0039] Specifically, in the lifting oil circuit driven by the hydraulic pump 2, the motor 3 is coaxially arranged with the hydraulic pump 2. The oil outlet of the hydraulic oil tank 1 is connected to the inlet of the hydraulic pump 2. The outlet of the hydraulic pump 2 is connected to the inlet of the first one-way valve 5. The outlet of the first one-way valve 5 is connected to the inlet of the three-position three-way solenoid valve 6. The outlet of the three-position three-way solenoid valve 6 is connected to the inlet of the throttle valve 7. The outlet of the throttle valve 7 is connected to the rodless chamber of the first hydraulic cylinder 8 and the second hydraulic cylinder 9. The rod chamber of the first hydraulic cylinder 8 and the second hydraulic cylinder 9 is connected to the oil return port of the hydraulic oil tank 1. The inlet of the first overflow valve 4 is connected to the first bypass interface led out of the pipeline between the outlet of the hydraulic pump 2 and the inlet of the first one-way valve 5. The outlet of the first overflow valve 4 is connected to the oil return port of the hydraulic oil tank 11.
[0040] In the energy release auxiliary driving oil circuit of the hydraulic accumulator, the inlet of the third check valve 19 is connected to the outlet of the second check valve 10, and the second bypass interface led out of the pipeline between the inlets of the first two-position two-way solenoid valve 11, the second two-position two-way solenoid valve 14 and the third two-position two-way solenoid valve 17. The outlet of the third check valve 19 is connected to the inlet of the fourth two-position two-way solenoid valve 18. The outlet of the fourth two-position two-way solenoid valve 18 is connected to the inlet of the throttle valve 7.
[0041] In the potential energy recovery oil circuit of the fork descent. The return oil outlet of the three-position three-way solenoid valve 6 is connected to the inlet of the second one-way valve 10. The first two-position two-way solenoid valve 11, the second two-position two-way solenoid valve 14 and the third two-position two-way solenoid valve 17 are arranged in parallel. The second one-way valve 10 is connected to the inlets of the first two-position two-way solenoid valve 11, the second two-position two-way solenoid valve 14 and the third two-position two-way solenoid valve 17. The first two-position two-way solenoid valve 11 is connected to the inlet of the first hydraulic accumulator 12. The outlet of the first hydraulic accumulator 12 is connected to the inlet of the second relief valve 13. The outlet of the second relief valve 13 is connected to the return oil port of the hydraulic oil tank 11. The outlet of the second two-position two-way solenoid valve 14 is connected to the inlet of the second hydraulic accumulator 15. The outlet of the second hydraulic accumulator 15 is connected to the inlet of the third relief valve 16. The outlet of the third relief valve 16 is connected to the return oil port of the hydraulic oil tank 1. The outlet of the third 2-position 2-way solenoid valve 17 is communicated with the oil return port of the hydraulic oil tank 1 .
[0042] The working principle of the fork when it is lowered is as follows: when the load is lowered, the hydraulic oil in the rodless chamber of the first hydraulic cylinder 8 and the second hydraulic cylinder 9 is discharged, and passes through the throttle valve 7, the three-position three-way solenoid valve 6 and the second one-way valve 10, and is stored in the first hydraulic accumulator 12 and the second hydraulic accumulator 15 through the first two-position two-way solenoid valve 11 and the second two-position two-way solenoid valve 14. In this way, the gravitational potential energy of the load is converted into hydraulic energy in the first hydraulic accumulator 12 and the second hydraulic accumulator 15. At this time, the hydraulic pump 2 is in a stopped state.
[0043] The working principle of the fork when it is rising is as follows: the hydraulic oil in the first hydraulic accumulator 12 and the second hydraulic accumulator 15 is released to the rodless chamber inlet of the first hydraulic cylinder 8 and the second hydraulic cylinder 9 in sequence, so that the energy recovered by the first hydraulic accumulator 12 and the second hydraulic accumulator 15 can directly drive the fork frame to lift the load, thereby achieving the purpose of energy saving. At this time, the hydraulic pump 2 can stop working or run synchronously to deliver hydraulic oil to the system to speed up the rising speed.
[0044] Specifically, when the system performs a lifting operation: the motor 3 drives the hydraulic pump 2 to supply the hydraulic oil in the hydraulic oil tank 1 to the entire oil circuit. The hydraulic oil passes through the first one-way valve 5, the three-position three-way solenoid valve 6 and the throttle valve 7, and enters the rodless chamber of the first hydraulic cylinder 8 and the second hydraulic cylinder 9 to realize the lifting movement of the forklift.
[0045] When the system performs energy recovery: the hydraulic oil in the rodless chambers of the first hydraulic cylinder 8 and the second hydraulic cylinder 9 passes through the throttle valve 7, the three-position three-way solenoid valve 6 and the second one-way valve 10 under the gravitational potential energy of the cargo, and enters the first hydraulic accumulator 12 and the second hydraulic accumulator 15 through the first two-position two-way solenoid valve 11 and the second two-position two-way solenoid valve 14 respectively to realize potential energy recovery.
[0046] When the system releases energy: the hydraulic oil in the first hydraulic accumulator 12 and the second hydraulic accumulator 15 flows through the second bypass through the first two-position two-way solenoid valve 11 and the second two-position two-way solenoid valve 14 respectively, and flows into the rodless chamber of the first hydraulic cylinder 8 and the second hydraulic cylinder 9 through the third one-way valve 19, the fourth two-position two-way solenoid valve 18 and the throttle valve 7 to perform lifting movement again, thereby realizing energy recycling.
[0047] The utility model embodiment of a forklift's graded hydraulic recovery auxiliary drive system introduces multiple hydraulic accumulators to realize the energy-saving technology of hydraulic drive and energy recovery on the basis of the motor 3 and the hydraulic pump 2 jointly realizing the hydraulic drive system, further improving the energy recovery capacity of the forklift hydraulic system. The potential energy recovery oil circuit under different oil pressures is separated by a two-position two-way solenoid valve, and hydraulic accumulators with different initial pressures are selected to work according to the different hydraulic oil pressures, so that multiple hydraulic accumulators can work in coordination. The loss of oil energy in the oil circuit is reduced. The utilization rate of energy is improved.
[0048] Embodiment 2: The present application further provides a forklift, which comprises a forklift auxiliary drive system for graded hydraulic recovery as described in any paragraph of Embodiment 1.
[0049] The above description is only the preferred implementation of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.
Claims
1. A graded recovery hydraulic auxiliary drive system for a forklift, characterized in that: The invention comprises a hydraulic oil tank (1), a hydraulic pump (2), an electric motor (3), a three-position three-way solenoid valve (6), a hydraulic oil cylinder, a first two-position two-way solenoid valve (11), a first hydraulic accumulator (12), a second two-position two-way solenoid valve (14), a second hydraulic accumulator (15), a third two-position two-way solenoid valve (17), and a fourth two-position two-way solenoid valve (18); wherein the hydraulic oil cylinder is used to drive the fork of the forklift to move up and down; The output shaft of the electric motor (3) is connected to the hydraulic pump (2) for driving the hydraulic pump (2) to work; the oil inlet pipeline of the hydraulic pump (2) is connected to the hydraulic oil tank (1); the oil outlet pipeline of the hydraulic pump (2) is connected to the oil inlet of the three-position three-way solenoid valve (6); the oil outlet pipeline of the three-position three-way solenoid valve (6) is connected to the rodless chamber of the hydraulic cylinder; the oil return pipeline of the three-position three-way solenoid valve (6) is connected to the first working interface of the first two-position two-way solenoid valve (11), the second two-position two-way solenoid valve (14) and the third two-position two-way solenoid valve (17); the first two-position two-way solenoid valve (11 ) is connected to the first hydraulic accumulator (12); the second working interface pipeline of the second two-position two-way solenoid valve (14) is connected to the second hydraulic accumulator (15); the second working interface pipeline of the third two-position two-way solenoid valve (17) is connected to the hydraulic oil tank (1); the first working interface pipeline of the fourth two-position two-way solenoid valve (18) is connected to the first working interfaces of the first two-position two-way solenoid valve (11), the second two-position two-way solenoid valve (14) and the third two-position two-way solenoid valve (17); the second working interface pipeline of the fourth two-position two-way solenoid valve (18) is connected to the rodless chamber of the hydraulic cylinder; The first two-position two-way solenoid valve (11), the second two-position two-way solenoid valve (14) and the third two-position two-way solenoid valve (17) are all structures without exhaust ports; the oil outlet of the three-position three-way solenoid valve (6) is configured to be switchably connected or disconnected with the oil inlet and the oil return port; and the pressure of the first hydraulic accumulator (12) is not greater than the pressure of the second hydraulic accumulator (15).
2. The auxiliary drive system of the graded recovery hydraulic system of a forklift according to claim 1 is characterized in that , the auxiliary drive system for graded hydraulic recovery of a forklift also includes a first overflow valve (4) and a first check valve (5); The oil inlet pipeline of the first non-return valve (5) is connected to the oil outlet of the hydraulic pump (2); the oil outlet pipeline of the first non-return valve (5) is connected to the oil inlet of the three-position three-way solenoid valve (6); the oil inlet pipeline of the first overflow valve (4) is connected to the oil outlet of the hydraulic pump (2); and the oil outlet pipeline of the first overflow valve (4) is connected to the hydraulic oil tank (1).
3. The auxiliary drive system of the graded recovery hydraulic pressure of a forklift according to claim 1 is characterized in that The auxiliary drive system for graded hydraulic recovery of a forklift also comprises a throttle valve (7); the throttle valve (7) pipeline is connected between the oil outlet of the three-position three-way solenoid valve (6) and the rodless chamber of the hydraulic cylinder; The number of hydraulic cylinders of the graded hydraulic recovery auxiliary drive system of the forklift is two; wherein the two hydraulic cylinders are respectively a first hydraulic cylinder (8) and a second hydraulic cylinder (9); and the first hydraulic cylinder (8) and the second hydraulic cylinder (9) are connected in parallel.
4. The auxiliary drive system of the graded recovery hydraulic pressure of a forklift according to claim 1 is characterized in that The auxiliary drive system for graded hydraulic recovery of a forklift further comprises a second one-way valve (10); the oil inlet pipeline of the second one-way valve (10) is connected to the oil return port of the three-position three-way solenoid valve (6); the oil outlet pipeline of the second one-way valve (10) is connected to the first working interfaces of the first two-position two-way solenoid valve (11), the second two-position two-way solenoid valve (14) and the third two-position two-way solenoid valve (17).
5. The auxiliary drive system of the graded recovery hydraulic pressure of a forklift according to claim 1 is characterized in that The auxiliary drive system for graded hydraulic pressure recovery of a forklift further comprises a second overflow valve (13) and a third overflow valve (16); the oil inlet of the second overflow valve (13) is connected to the first hydraulic accumulator (12); the oil inlet of the third overflow valve (16) is connected to the second hydraulic accumulator (15); the oil outlets of the second overflow valve (13) and the third overflow valve (16) are connected to the hydraulic oil tank (1).
6. The auxiliary drive system of the graded recovery hydraulic pressure of a forklift according to claim 3 is characterized in that The auxiliary drive system for graded hydraulic recovery of a forklift further comprises a third one-way valve (19); the oil inlet pipeline of the third one-way valve (19) is connected to the first working interface of the first two-position two-way solenoid valve (11) and the second two-position two-way solenoid valve (14); the oil outlet pipeline of the third one-way valve (19) is connected between the oil outlet of the three-position three-way solenoid valve (6) and the throttle valve (7).
7. A forklift, characterized in that: An auxiliary drive system for a forklift truck comprising a graded hydraulic recovery system as claimed in any one of claims 1 to 6.