Potential energy recovery hydraulic system and engineering machinery

Abstract

The utility model provides a potential energy recovery hydraulic system. The potential energy recovery hydraulic system comprises an oil inlet path and an energy storage branch path, the number of the energy storage branches is multiple, and each energy storage branch communicates with the oil inlet path. Each energy storage branch is provided with an energy accumulator and an oil inlet control valve, and the oil inlet control valves are located on the front sides of the energy accumulators and used for controlling liquid path conduction between the energy storage branches and the oil inlet path. And the internal pressures of the energy accumulators on at least two energy storage branches are different. Meanwhile, the utility model further provides engineering machinery. Compared with the prior art, the potential energy recovery hydraulic system and the engineering machinery can improve the potential energy recovery efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of potential energy recovery, in particular to a potential energy recovery hydraulic system and engineering machinery. Background Art

[0002] Construction machinery is an important part of the equipment industry and is a necessary mechanical equipment for mechanized construction projects. With the development of economy and technology, construction machinery is increasingly used in various construction fields. Construction machinery is usually equipped with a luffing mechanism, and the up and down operation of the luffing mechanism is a common working condition. When the luffing mechanism drops, it drives the heavy load to fall, and there is a lot of gravitational potential energy in this falling process. Therefore, recycling the gravitational potential energy during the descent is of great practical significance to the energy saving of the equipment.

[0003] In the prior art, there are mainly two hydraulic recovery schemes for recovering the potential energy when the luffing mechanism descends: one scheme is to use a double-acting pump to recover and generate electricity. When the luffing mechanism descends, the double-acting pump is used as a motor to drive the generator to generate electricity; the other scheme is to use a single accumulator or multiple accumulators in series to recover hydraulic energy, and the recovered hydraulic energy is used as auxiliary energy for the hydraulic system.

[0004] However, the potential energy of the luffing mechanism is constantly decreasing during the process of descending. The disadvantage of using a double-acting pump to recover power generation is that the generated electric energy is also variable when using the changing potential energy to generate electricity, which is inconvenient to store. In addition, the hydraulic system cannot perform other work when the double-acting pump is recovering the potential energy. The disadvantage of using a single accumulator or multiple accumulators in series to recover hydraulic energy is that due to the pre-charged air pressure of the accumulator, when the accumulator is used to recover hydraulic energy, the internal pressure of the accumulator is higher than the hydraulic pressure of the hydraulic oil squeezed out by the luffing cylinder, and the potential energy can no longer be recovered, resulting in a low efficiency of potential energy recovery. Utility Model Content

[0005] The potential energy recovery scheme adopted in the prior art can recover potential energy to a certain extent, but the potential energy recovery efficiency is low and the technical problem of not being able to efficiently recover potential energy is solved. The utility model provides a potential energy recovery hydraulic system, in which a plurality of energy storage branches arranged in parallel are arranged in the energy storage circuit, and the internal pressure of the accumulator in each energy storage branch is different, so that when the pressure of the hydraulic oil flowing in is high, it can be recovered through the accumulator with higher internal pressure, and when the pressure of the hydraulic oil flowing in becomes low, it can be recovered through the accumulator with lower internal pressure. By recycling with multiple accumulators, the hydraulic oil brought by potential energy of different levels can be fully recovered, the potential energy recovery efficiency is higher, and the potential energy can be efficiently recovered.

[0006] A potential energy recovery hydraulic system, comprising an oil inlet circuit and an energy storage branch circuit;

[0007] There are multiple energy storage branches, each of which is connected to the oil inlet passage respectively;

[0008] Each of the energy storage branches is provided with an accumulator and an oil inlet control valve, wherein the oil inlet control valve is located at the front side of the accumulator and is used to control the fluid conduction between the energy storage branch and the oil inlet circuit;

[0009] Among them, the internal pressures of the accumulators on at least two of the energy storage branches are different.

[0010] Preferably, a continuous pressure booster is provided in the energy storage branch having a lower internal pressure of the energy storage device, and the continuous pressure booster is located at the front side of the energy storage device.

[0011] Preferably, it further comprises an oil outlet circuit, and each of the energy storage branches is arranged between the oil inlet circuit and the oil outlet circuit;

[0012] Each of the energy storage branches is provided with an oil outlet control valve, which is located at the rear side of the accumulator and is used to control the fluid conduction between the energy storage branch and the oil outlet.

[0013] Preferably, it also includes an energy storage and power generation branch connected to the oil outlet;

[0014] The energy storage power generation branch is provided with an energy storage motor and an energy storage control valve, wherein the energy storage control valve is located at the front side of the energy storage motor and is used to control the fluid conduction between the energy storage power generation branch and the oil outlet;

[0015] It also includes a generator and a battery. The generator is connected to the rotating shaft of the energy storage motor, and the battery is connected to the generator.

[0016] Preferably, the energy storage power generation branch is further provided with a first pressure reducing valve and a first sequence valve, and the first pressure reducing valve and the first sequence valve are located between the energy storage motor and the energy storage control valve.

[0017] Preferably, a first speed regulating valve is further provided on the energy storage power generation branch, and the first speed regulating valve is located between the energy storage motor and the energy storage control valve.

[0018] Preferably, it also includes a drive branch connected to the oil outlet;

[0019] The driving branch is communicated with an external driving mechanism, and a driving control valve is arranged on the driving branch, and the driving control valve is used to control the fluid conduction between the driving branch and the oil outlet.

[0020] Preferably, a second pressure reducing valve and a second sequence valve are further provided on the driving branch, and the second pressure reducing valve and the second sequence valve are located at the rear side of the driving control valve.

[0021] Preferably, a second speed regulating valve is further provided on the driving branch, and the second speed regulating valve is located at the rear side of the driving control valve.

[0022] An engineering machine is provided with a potential energy recovery hydraulic system as described in any one of the above, wherein the oil inlet is connected to a rodless chamber of a variable-length oil cylinder in the engineering machine.

[0023] Compared with the prior art, the potential energy recovery hydraulic system provided by the utility model includes an oil inlet and an energy storage branch; the energy storage branch is provided with a plurality of energy storage branches, each of which is connected to the oil inlet; each of the energy storage branches is provided with an accumulator and an oil inlet control valve, the oil inlet control valve is located at the front side of the accumulator, and is used to control the fluid conduction between the energy storage branch and the oil inlet; wherein, the internal pressures of the accumulators on at least two of the energy storage branches are different. The potential energy recovery hydraulic system includes a plurality of energy storage branches, and the internal pressures of the accumulators on at least two of the energy storage branches are different, so that in the process of potential energy recovery, when the potential energy is large and the hydraulic oil pressure is high, the potential energy can be recovered through the accumulator with a large internal pressure, and when the potential energy gradually decreases and the hydraulic oil pressure becomes low, the potential energy can be recovered through the accumulator with a small internal pressure, and when the potential energy becomes small, the potential energy can still be recovered, thereby improving the potential energy recovery efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic structural diagram of a potential energy recovery hydraulic system provided in an embodiment. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] It should be noted that when a component is referred to as being "fixed on", "installed on" or "set on" another component, it can be directly on the other component or indirectly set on the other component; when a component is "connected" to another component, or a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component.

[0028] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0030] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0031] The utility model provides a potential energy recovery hydraulic system, which includes an oil inlet and an energy storage branch; the energy storage branch is provided with a plurality of energy storage branches, each of which is connected to the oil inlet; each of the energy storage branches is provided with an accumulator and an oil inlet control valve, the oil inlet control valve is located at the front side of the accumulator, and is used to control the fluid conduction between the energy storage branch and the oil inlet; wherein, the internal pressures of the accumulators on at least two of the energy storage branches are different. The potential energy recovery hydraulic system includes a plurality of energy storage branches, and the internal pressures of the accumulators on at least two of the energy storage branches are different, so that in the process of potential energy recovery, when the potential energy is large and the hydraulic oil pressure is high, the potential energy can be recovered through the accumulator with a large internal pressure, and when the potential energy gradually decreases and the hydraulic oil pressure becomes low, the potential energy can be recovered through the accumulator with a small internal pressure, and when the potential energy becomes small, the potential energy can still be recovered, thereby improving the potential energy recovery efficiency.

[0032] Please refer to Figure 1 . This embodiment provides a potential energy recovery hydraulic system 100, which is used to recover the potential energy of the variable amplitude mechanism of engineering machinery in the descending condition, and is a graded recovery scheme for accumulators. The pain point of existing potential energy recovery schemes is: how to efficiently recover and utilize the scattered and changing potential energy without affecting the normal operation of the equipment. The potential energy recovery hydraulic system 100 is mainly used to solve the problem of efficient recovery of potential energy. In some embodiments, the potential energy recovery hydraulic system 100 can also solve the problem of efficient recovery and utilization of potential energy.

[0033] The potential energy recovery hydraulic system 100 includes an oil inlet 10 and an energy storage branch 20. A plurality of energy storage branches 20 are provided, and each of the energy storage branches 20 is respectively connected to the oil inlet 10. That is, all of the energy storage branches 20 are respectively connected to the oil inlet 10, and the hydraulic oil in the oil inlet 10 can enter each of the energy storage branches 20.

[0034] Each of the energy storage branches 20 is provided with an accumulator 21 and an oil inlet control valve 22. The oil inlet control valve 22 is located at the front side of the accumulator 21 and is used to control the fluid conduction between the energy storage branch 20 and the oil inlet 10. That is, each of the energy storage branches 20 is provided with the oil inlet control valve 22, and the oil inlet control valve 22 is used to control the fluid conduction between the energy storage branch 20 and the oil inlet 10. Among them, the internal pressures of the accumulators 21 on at least two of the energy storage branches 20 are different. That is, among the multiple energy storage branches 20, the internal pressures of the accumulators 21 on at least two of the energy storage branches 20 are different, and among the two energy storage branches 20, the internal pressure of the accumulator 21 on one of the energy storage branches 20 is less than the internal pressure of the accumulator 21 on the other energy storage branch 20.

[0035] It should be noted that the oil inlet control valve 22 being located on the front side of the accumulator 21 means that the position of the oil inlet control valve 22 on the energy storage branch 20 is closer to the oil inlet circuit 10 than to the accumulator 21, so that when the hydraulic oil flows from the oil inlet circuit 10 into the energy storage branch 20, it needs to pass through the oil inlet control valve 22 before flowing through the accumulator 21.

[0036] When the potential energy is recovered, when the potential energy is high and the hydraulic oil pressure is high, the oil inlet control valve 22 on the energy storage branch 20 where the accumulator 21 with a higher internal pressure is located is opened, so that the hydraulic energy can be recovered through the accumulator 21 with a higher internal pressure; and when the potential energy is reduced, the oil inlet control valve 22 on the energy storage branch 20 where the accumulator 21 with a lower internal pressure is located is opened, so that the hydraulic energy can be recovered through the accumulator 21 with a lower internal pressure, thereby improving the potential energy recovery efficiency.

[0037] The fact that there are multiple energy storage branches 20 means that there are at least two energy storage branches 20. When there are only two energy storage branches 20, the internal pressures of the energy accumulators 21 on the two energy storage branches 20 are different. When there are more than two energy storage branches 20, the internal pressures of the energy accumulators 21 in at least two of the energy storage branches 20 are different.

[0038] For example, in Figure 1In the illustrated embodiment, three energy storage branches 20 are provided. For the convenience of description, the three energy storage branches 20 are respectively a first energy storage branch 201, a second energy storage branch 202, and a third energy storage branch 203. The internal pressure of the accumulator 21 in the first energy storage branch 201 is higher than the internal pressure of the accumulator 21 in the second energy storage branch 202, and the internal pressure of the accumulator 21 in the second energy storage branch 202 is higher than the internal pressure of the accumulator 21 in the third energy storage branch 203. In this embodiment, when the potential energy is recovered, the oil inlet control valve 22 in the first energy storage branch 201 is opened, the hydraulic oil in the oil inlet circuit 10 flows into the first energy storage branch 201, and the hydraulic oil is recovered and stored through the accumulator 21 on the first energy storage branch 201. When the hydraulic oil pressure in the accumulator 21 rises to be equal to the hydraulic oil pressure flowing into the oil inlet circuit 10, the oil inlet control valve 22 in the first energy storage branch 201 is closed; then, the oil inlet control valve 22 in the second energy storage branch 202 is opened, and the hydraulic oil in the oil inlet circuit 10 is The hydraulic oil flows into the second energy storage branch 202, and the hydraulic oil is recovered and stored by the accumulator 21 on the second energy storage branch 202. When the hydraulic oil pressure in the accumulator 21 rises to be equal to the hydraulic oil pressure flowing into the oil inlet 10, the oil inlet control valve 22 in the second energy storage branch 202 is closed; then, the oil inlet control valve 22 in the third energy storage branch 203 is opened, and the hydraulic oil in the oil inlet 10 flows into the third energy storage branch 203, and the hydraulic oil is recovered and stored by the accumulator 21 on the third energy storage branch 203. Of course, in other embodiments, the potential energy recovery hydraulic system 100 can be provided with more energy storage branches 20. In this embodiment, only three energy storage branches 20 are taken as an example for description.

[0039] It is understandable that although there are solutions for recovering potential energy using accumulators in the prior art, they use a single accumulator or multiple accumulators connected in series to recover hydraulic energy. However, due to the pre-charged air pressure of the accumulator, when the accumulator is used to recover hydraulic energy, the internal pressure of the accumulator is higher than the hydraulic pressure of the hydraulic oil squeezed out by the variable amplitude oil cylinder, and the potential energy can no longer be recovered, resulting in a low efficiency of potential energy recovery.

[0040] In the potential energy recovery hydraulic system 100 provided in this embodiment, a plurality of energy storage branches 20 are provided, and the internal pressures of the accumulators 21 on at least two of the energy storage branches 20 are different, so that when the potential energy is reduced and the hydraulic oil pressure is reduced, the hydraulic oil can be recovered and stored through the accumulator 21 with a smaller internal pressure, and the potential energy recovery efficiency is higher, and the scattered and changing potential energy can be efficiently recovered. The use of a multi-stage accumulator can fully recover potential energy of different levels.

[0041] Preferably, in one embodiment, a continuous booster 23 is provided in the energy storage branch 20 where the internal pressure of the accumulator 21 is relatively low, and the continuous booster 23 is located at the front side of the accumulator 21. It should be noted that the continuous booster 23 being located at the front side of the accumulator 21 means that the position of the continuous booster 23 on the energy storage branch 20 is closer to the oil inlet 10 than the accumulator 21, so that when the hydraulic oil flows from the oil inlet 10 into the energy storage branch 20, it needs to pass through the continuous booster 23 before flowing through the accumulator 21. By setting the continuous booster 23, the potential energy can be recovered even when the potential energy is small and the hydraulic oil pressure is small.

[0042] For example, in Figure 1 In the illustrated embodiment, the continuous booster 23 is provided on the third energy storage branch 203. When the potential energy continuously decreases and the pressure of the hydraulic oil squeezed out of the rodless chamber of the boom cylinder is equal to or less than the pressure in the accumulator 21 on the third energy storage branch 203, the continuous booster 23 operates to boost the pressure of the hydraulic oil squeezed out of the rodless chamber of the boom cylinder and transport it to the accumulator 21. The whole process completes the recovery of hydraulic energy, which is all stored in the accumulator.

[0043] Preferably, in one embodiment, the potential energy recovery hydraulic system 100 further includes an oil outlet 30, and each of the energy storage branches 20 is arranged between the oil inlet 10 and the oil outlet 20, that is, a plurality of the energy storage branches 20 are arranged in parallel between the oil inlet 10 and the oil outlet 20. An oil outlet control valve 24 is arranged on each of the energy storage branches 20, and the oil outlet control valve 24 is located at the rear side of the accumulator 21 to control the conduction of the fluid between the energy storage branch 20 and the oil outlet 30. It should be noted that the oil outlet control valve 24 is located at the rear side of the accumulator 21, which means that the position of the oil outlet control valve 24 on the energy storage branch 20 is farther away from the oil inlet 10 than the accumulator 21, so that when the hydraulic oil flows from the oil inlet 10 into the energy storage branch 20, it needs to pass through the accumulator 21 first, and then flow through the oil outlet control valve 24. The oil outlet passage 30 can be connected to other oil passages, so that the hydraulic oil stored in the accumulator 21 can be released to the outside through the oil outlet passage 30 for utilization.

[0044] Preferably, in one embodiment, the potential energy recovery hydraulic system 100 further includes an energy storage power generation branch 40 connected to the oil outlet 30, and an energy storage motor 41 and an energy storage control valve 42 are provided on the energy storage power generation branch 40, and the energy storage control valve 42 is located at the front side of the energy storage motor 41, and is used to control the fluid conduction between the energy storage power generation branch 40 and the oil outlet 30. It should be noted that the energy storage control valve 42 is located at the front side of the energy storage motor 41, which means that the position of the energy storage control valve 42 on the energy storage power generation branch 40 is closer to the oil outlet 30 than the energy storage motor 41, so that when the hydraulic oil flows from the oil outlet 30 into the energy storage power generation branch 40, it needs to pass through the energy storage control valve 42 before flowing through the energy storage motor 41. The potential energy recovery hydraulic system 100 further includes a generator 50 and a battery 60, wherein the generator 50 is connected to the rotating shaft of the energy storage motor 41, and the battery 60 is connected to the generator 50. Therefore, when the hydraulic oil of the oil outlet 30 flows into the energy storage power generation branch 40, it can drive the energy storage motor 41 to rotate, so that the energy storage motor 41 drives the generator 50 to generate electricity and store it in the battery 60, thereby efficiently recovering and utilizing the scattered and changing potential energy.

[0045] For example, in Figure 1 In the illustrated embodiment, after the oil outlet control valve 24 on the first energy storage branch 201 is opened, the hydraulic oil stored in the accumulator 21 on the first energy storage branch 201 flows into the oil outlet 30, and then flows into the energy storage power generation branch 40 to drive the energy storage motor 41 to generate electricity; similarly, after the oil outlet control valve 24 on the second energy storage branch 202 is opened, the hydraulic oil stored in the accumulator 21 on the second energy storage branch 202 flows into the oil outlet 30, and then flows into the energy storage power generation branch 40 to drive the energy storage motor 41 to generate electricity; similarly, after the oil outlet control valve 24 on the third energy storage branch 203 is opened, the hydraulic oil stored in the accumulator 21 on the third energy storage branch 203 flows into the oil outlet 30, and then flows into the energy storage power generation branch 40 to drive the energy storage motor 41 to generate electricity.

[0046] Preferably, in one embodiment, the energy storage power generation branch 40 is further provided with a first pressure reducing valve 43 and a first sequence valve 44, and the first pressure reducing valve 43 and the first sequence valve 44 are located between the energy storage motor 41 and the energy storage control valve 42. By using the first pressure reducing valve 43 and the first sequence valve 44, the pressure of the output high-pressure hydraulic oil can be corrected.

[0047] Preferably, in one embodiment, the energy storage power generation branch 40 is further provided with a first speed regulating valve 45, and the first speed regulating valve 45 is located between the energy storage motor 41 and the energy storage control valve 42. By adopting the first speed regulating valve 45, the flow rate of the output high-pressure hydraulic oil can be adjusted to ensure a stable output of the hydraulic oil.

[0048] Preferably, in one embodiment, the potential energy recovery hydraulic system 100 further includes a drive branch 70 connected to the oil outlet 30, the drive branch 70 is connected to an external drive mechanism, and a drive control valve 71 is provided on the drive branch 70, and the drive control valve 71 is used to control the fluid conduction between the drive branch 70 and the oil outlet 30. Specifically, the external drive mechanism can be any power mechanism on the engineering machinery. The oil outlet 30 is connected to the external drive mechanism through the drive branch 70, so that the scattered and changing potential energy can be efficiently recovered and utilized.

[0049] For example, in Figure 1 In the illustrated embodiment, after the oil outlet control valve 24 on the first energy storage branch 201 is opened, the hydraulic oil stored in the accumulator 21 on the first energy storage branch 201 flows into the oil outlet 30, and then flows into the external drive mechanism through the drive branch 70; similarly, after the oil outlet control valve 24 on the second energy storage branch 202 is opened, the hydraulic oil stored in the accumulator 21 on the second energy storage branch 202 flows into the oil outlet 30, and then flows into the external drive mechanism through the drive branch 70; similarly, after the oil outlet control valve 24 on the third energy storage branch 203 is opened, the hydraulic oil stored in the accumulator 21 on the third energy storage branch 203 flows into the oil outlet 30, and then flows into the external drive mechanism through the drive branch 70.

[0050] Preferably, in one embodiment, the drive branch 70 is further provided with a second pressure reducing valve 72 and a second sequence valve 73, and the second pressure reducing valve 72 and the second sequence valve 73 are located at the rear side of the drive control valve 71. The second pressure reducing valve 72 and the second sequence valve 73 can be used to correct the pressure of the output high-pressure hydraulic oil.

[0051] Preferably, in one embodiment, the drive branch 70 is further provided with a second speed regulating valve 74, and the second speed regulating valve 74 is located at the rear side of the drive control valve 71. By adopting the second speed regulating valve 74, the flow rate of the output high-pressure hydraulic oil can be adjusted to ensure a stable output of the hydraulic oil.

[0052] Preferably, in one embodiment, each of the energy storage branches 20 is provided with a first one-way valve, the first one-way valve is located in front of the oil inlet control valve 22, and the inlet of the first one-way valve faces one side of the oil inlet circuit 10. Preferably, in one embodiment, each of the energy storage branches 20 is also provided with a second one-way valve, the second one-way valve is located at the rear of the accumulator 21, and the outlet of the second one-way valve faces one side of the oil outlet circuit 30. The setting of the one-way valve can better control the flow direction of the hydraulic oil in the energy storage branch 20.

[0053] Preferably, in one embodiment, a hydraulic sensor is provided on each of the energy storage branches 20, so that the pressure of the hydraulic oil in each of the energy storage branches 20 can be detected. Preferably, in one embodiment, a hydraulic sensor is provided on each of the oil inlet 10 and the oil outlet 30, so that the pressure of the hydraulic oil in the oil inlet 10 and the oil outlet 30 can be detected.

[0054] Preferably, in one embodiment, the oil inlet control valve 22, the oil outlet control valve 24, the energy storage control valve 42, and the drive control valve 71 are all solenoid valves. More preferably, in one embodiment, the hydraulic sensor on each energy storage branch 20, the oil inlet circuit 10, the oil inlet control valve 22, the oil outlet control valve 24, the hydraulic sensor on the oil outlet circuit 30, the energy storage control valve 42, and the drive control valve 71 can be connected to a controller respectively, so as to be automatically controlled by the controller. The controller can specifically adopt any mechanism with detection and control functions, such as a PLC (Programmable Logic Controller), a single-chip microcomputer, etc.

[0055] In one embodiment, when recovering potential energy, the potential energy recovery hydraulic system 100 can not only smoothly convert it into hydraulic energy and electrical energy for storage, but also output it as a stable auxiliary hydraulic power source, thus having multiple functions.

[0056] Meanwhile, in one embodiment, a construction machine is provided, which is applied with the potential energy recovery hydraulic system 100, and the oil inlet 10 is connected with the rodless chamber of the luffing cylinder 200 in the construction machine. When the luffing mechanism 300 descends under the action of gravity, the luffing cylinder 200 is pressed down to retract, and when the luffing cylinder 200 retracts, the hydraulic oil in the rodless chamber of the luffing cylinder 200 is squeezed out, and the gravitational potential energy of the luffing mechanism 300 is converted into hydraulic energy and flows into the oil inlet 10.

[0057] The above is only an implementation method of the present invention. It should be pointed out that a person skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements are all within the protection scope of the present invention.

Claims

1. A potential energy recovery hydraulic system, characterized in that: Including oil inlet circuit and energy storage branch circuit; There are multiple energy storage branches, each of which is connected to the oil inlet passage respectively; Each of the energy storage branches is provided with an accumulator and an oil inlet control valve, wherein the oil inlet control valve is located at the front side of the accumulator and is used to control the fluid conduction between the energy storage branch and the oil inlet circuit; Among them, the internal pressures of the accumulators on at least two of the energy storage branches are different.

2. The potential energy recovery hydraulic system according to claim 1, characterized in that: A continuous pressure booster is provided in the energy storage branch circuit where the internal pressure of the energy storage device is relatively low, and the continuous pressure booster is located at the front side of the energy storage device.

3. The potential energy recovery hydraulic system according to claim 1, characterized in that: It also includes an oil outlet circuit, and each of the energy storage branches is arranged between the oil inlet circuit and the oil outlet circuit; Each of the energy storage branches is provided with an oil outlet control valve, which is located at the rear side of the accumulator and is used to control the fluid conduction between the energy storage branch and the oil outlet.

4. The potential energy recovery hydraulic system according to claim 3, characterized in that: It also includes an energy storage and power generation branch circuit connected to the oil outlet circuit; The energy storage power generation branch is provided with an energy storage motor and an energy storage control valve, wherein the energy storage control valve is located at the front side of the energy storage motor and is used to control the fluid conduction between the energy storage power generation branch and the oil outlet; It also includes a generator and a battery. The generator is connected to the rotating shaft of the energy storage motor, and the battery is connected to the generator.

5. The potential energy recovery hydraulic system according to claim 4, characterized in that: The energy storage power generation branch is also provided with a first pressure reducing valve and a first sequence valve, and the first pressure reducing valve and the first sequence valve are located between the energy storage motor and the energy storage control valve.

6. The potential energy recovery hydraulic system according to claim 4, characterized in that: The energy storage power generation branch is also provided with a first speed regulating valve, and the first speed regulating valve is located between the energy storage motor and the energy storage control valve.

7. The potential energy recovery hydraulic system according to any one of claims 3 to 6, characterized in that: It also includes a drive branch circuit connected to the oil outlet circuit; The driving branch is communicated with an external driving mechanism, and a driving control valve is arranged on the driving branch, and the driving control valve is used to control the fluid conduction between the driving branch and the oil outlet.

8. The potential energy recovery hydraulic system according to claim 7, characterized in that: The drive branch is also provided with a second pressure reducing valve and a second sequence valve, and the second pressure reducing valve and the second sequence valve are located at the rear side of the drive control valve.

9. The potential energy recovery hydraulic system according to claim 7, characterized in that: The drive branch is also provided with a second speed regulating valve, and the second speed regulating valve is located at the rear side of the drive control valve.

10. An engineering machine, characterized in that: A potential energy recovery hydraulic system as claimed in any one of claims 1 to 9 is applied, wherein the oil inlet circuit is connected to the rodless chamber of the variable amplitude oil cylinder in the engineering machinery.

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