Weight lifting potential energy recovery energy-saving hydraulic control loop

Abstract

The utility model provides a heavy object lifting potential energy recovery energy-saving hydraulic control loop which comprises a set of oil source with variable pressure, a set of high-pressure energy accumulators, a set of low-pressure energy accumulators, a set of master control hydraulic proportional valve and a set of hydraulic control one-way valve combination capable of achieving energy recovery. In addition, the device further comprises a pressure sensor for detecting the pressure of the rodless cavity, a lifting hydraulic cylinder and the like. According to the utility model, the parallel control of a conventional control mode and a potential energy recovery energy-saving mode is realized through the same hydraulic proportional valve, the two control modes can be automatically switched, and the gravitational potential energy is recovered and reused while the lifting hydraulic cylinder is controlled to move in the potential energy recovery mode. The hydraulic control system is green, energy-saving, simple in structure and control and high in reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic control, in particular to an energy-saving hydraulic control circuit for recovering potential energy of lifting heavy objects. Background Art

[0002] In many heavy lifting equipment driven by hydraulic control systems, the gravity potential energy of the heavy objects and the lifting equipment itself can be recycled and reused to achieve energy-saving effects. For example, in the field of iron and steel metallurgy, the walking heating furnace, walking transport chain, coil transport trolley and other equipment, the weight of the equipment and the lifted heavy objects is often between tens of tons and thousands of tons. The potential energy recovery of heavy objects is crucial to the energy saving of the entire hydraulic system. In the past, the potential energy recovery technology mainly used special oil cylinders, rod cavity proportional valve control, pump control volume speed regulation and other technologies. These technologies require the addition of special hydraulic cylinders or control valve stations or hydraulic pump systems to achieve potential energy recovery. These special equipment not only takes up space but also increases the difficulty of control. The complex equipment structure and control bring more instability to the hydraulic system, and also bring a lot of inconvenience to the debugging and maintenance work. In addition, during the implementation process, it is necessary to incorporate new energy-saving systems into the pipelines of the conventional system, and some of them also need to manually switch some control valves to switch between the conventional mode and the potential energy recovery mode, which also causes problems such as increased investment, reduced stability and reliability of equipment operation, and too long transformation and debugging cycles. Utility Model Content

[0003] In view of the above-mentioned problems existing in the prior art, the utility model adopts the following technical solutions: a heavy object lifting potential energy recovery energy-saving hydraulic control circuit, comprising: a variable pressure oil source, a main control hydraulic proportional valve, a hydraulically controlled one-way valve combination that can realize energy recovery, an accumulator group, a lifting hydraulic cylinder and a pressure sensor for detecting the rodless chamber pressure; the accumulator group comprises a high-pressure accumulator and a low-pressure accumulator; the oil inlet and return oil circuits of the variable pressure oil source are connected to the hydraulically controlled one-way valve combination and the main control hydraulic proportional valve, the accumulator group is connected to the oil inlet of the variable pressure oil source, and the pressure sensor is connected to the rodless chamber oil circuit of the lifting hydraulic cylinder to detect the pressure of the rodless chamber; the hydraulically controlled one-way valve combination controls the rod chamber oil circuit of the lifting hydraulic cylinder; a set of the main control hydraulic proportional valve and the hydraulically controlled one-way valve combination can be used to cooperate to realize the speed control of switching between conventional control and potential energy recovery modes without the need to connect other pipelines in parallel.

[0004] Preferably, during the descent of the lifting hydraulic cylinder, the pressure oil in the accumulator group can be controlled by the hydraulically controlled one-way valve combination to directly connect to the rod chamber of the lifting hydraulic cylinder, while cutting off the oil path between the rod chamber of the lifting hydraulic cylinder and the T-port return oil of the main control hydraulic proportional valve.

[0005] Preferably, the hydraulically controlled one-way valve in the hydraulically controlled one-way valve combination is replaced by a two-way cartridge valve.

[0006] Preferably, the main control hydraulic proportional valve may be a proportional valve throttle valve or a proportional reversing valve.

[0007] Preferably, in the potential energy recovery mode, the ascent and descent of the lifting hydraulic cylinder are controlled by the same proportional electromagnet.

[0008] Preferably, in the potential energy recovery mode, the accumulator group is directly connected to the rod chamber of the lifting hydraulic cylinder, the pressure of the rodless chamber of the lifting hydraulic cylinder is greater than the pressure of the accumulator group, and a part of the rodless chamber pressure oil is recovered into the accumulator group after speed control by the main control hydraulic proportional valve, and the other part directly enters the rod chamber of the lifting hydraulic cylinder.

[0009] Preferably, the pressure is adjusted in real time according to the position and control requirements of the lifting hydraulic cylinder, so that multi-stage or stepless adjustment can be achieved.

[0010] Preferably, the normal mode or the potential energy recovery mode of the lifting hydraulic cylinder can be switched at any time according to the value detected by the pressure sensor.

[0011] Compared with the prior art, the utility model has at least the following advantages: the utility model provides a heavy object lifting potential energy recovery energy-saving hydraulic control system. In the process of descending after the heavy object is lifted, there is no need to add additional hydraulic proportional valves, hydraulic cylinders and hydraulic pumps. The same hydraulic proportional valve as the conventional control is used for speed control. While completing the equipment operation action control, the gravity potential energy is recovered. In addition, parallel pipeline access is not required on the A and B pipes of the lifting hydraulic cylinder, which greatly reduces the amount of pipeline construction in the hydraulic system and also reduces the complexity of the control system. It is a technical solution with low investment and low operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific implementation of the utility model, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0013] Figure 1 This is a working principle diagram of the potential energy recovery hydraulic control circuit provided in the embodiment of the utility model.

[0014] Figure 2 This is a working principle diagram of the accumulator provided in the embodiment of the utility model.

[0015] Figure 3 This is a partial working principle diagram of the potential energy recovery hydraulic control circuit provided in the embodiment of the utility model.

[0016] Figure markings: 1-lifting hydraulic cylinder, 2-variable pressure oil source, 3-oil inlet circuit, 4-oil return circuit, 5-main control hydraulic proportional valve, 6-first hydraulically controlled one-way valve, 7-second hydraulically controlled one-way valve, 8-first control valve, 9-high-pressure accumulator, 10-second control valve, 11-third hydraulically controlled one-way valve, 12-balancing valve, 13-pressure sensor, 14-fixed load, 15-weight, 16-low-pressure accumulator. DETAILED DESCRIPTION

[0017] The following embodiments of the technical solution of the utility model are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and are therefore only used as examples, and cannot be used to limit the protection scope of the utility model.

[0018] In the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element 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 invention.

[0019] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] See also Figure 1-Figure 3The embodiment provided by the utility model is a heavy object lifting potential energy recovery energy-saving hydraulic control circuit, comprising: a variable pressure oil source 2, a main control hydraulic proportional valve 5, a hydraulically controlled one-way valve combination capable of realizing energy recovery, an accumulator group, a lifting hydraulic cylinder 1 and a pressure sensor 13 for detecting the rodless chamber pressure; the accumulator group comprises a high-pressure accumulator 9 and a low-pressure accumulator 16; the oil inlet circuit 3 and the oil return circuit 4 of the variable pressure oil source 2 are connected to the hydraulically controlled one-way valve combination and the main control hydraulic proportional valve 5, the accumulator group is connected to the oil inlet circuit 3 of the variable pressure oil source 2, the pressure sensor 13 is connected to the rodless chamber oil circuit of the lifting hydraulic cylinder 1 to detect the pressure of the rodless chamber; the hydraulically controlled one-way valve combination controls the rod chamber oil circuit of the lifting hydraulic cylinder 1; the switching between the conventional control mode and the potential energy recovery mode can be completed by a set of main control hydraulic proportional valves 5 and a hydraulically controlled one-way valve combination capable of realizing energy recovery, without the need to connect other pipelines in parallel.

[0021] Furthermore, during the descent of the lifting hydraulic cylinder 1, in the potential energy recovery mode, the pressure oil in the accumulator group can be controlled by the hydraulically controlled one-way valve combination to directly connect to the rod chamber of the lifting hydraulic cylinder 1, while cutting off the oil path between the rod chamber of the lifting hydraulic cylinder 1 and the T-port return oil of the main control hydraulic proportional valve 5.

[0022] The accumulator group is connected to the oil inlet circuit 3 via two third hydraulically controlled one-way valves 11 ; and the two third hydraulically controlled one-way valves 11 are controlled by the second control valve 10 .

[0023] The hydraulically controlled one-way valve combination comprises: a first hydraulically controlled one-way valve 6 and a second hydraulically controlled one-way valve 7 ; the first hydraulically controlled one-way valve 6 and the second hydraulically controlled one-way valve 7 are controlled by a first control valve 8 .

[0024] See also Figure 1-Figure 3 In other embodiments, the hydraulically controlled one-way valve in the hydraulically controlled one-way valve combination is replaced by a two-way cartridge valve.

[0025] See also Figure 1-Figure 3 In other embodiments, in the potential energy recovery mode, the rise and fall of the lifting hydraulic cylinder 1 are controlled by the same proportional electromagnet.

[0026] See also Figure 1-Figure 3 In other embodiments, in the potential energy recovery mode, the accumulator group is directly connected to the rod chamber of the lifting hydraulic cylinder 1, the pressure of the rodless chamber of the lifting hydraulic cylinder 1 is greater than the pressure of the accumulator group, and the pressure oil in the rodless chamber of the lifting hydraulic cylinder 1 is recovered into the accumulator group after the speed is controlled by the main control hydraulic proportional valve 5, and the other part directly enters the rod chamber of the lifting hydraulic cylinder 1.

[0027] See also Figure 1-Figure 3 In other embodiments, the pressure is adjusted in real time according to the position and control requirements of the lifting hydraulic cylinder 1, and multi-level or stepless adjustment can be achieved.

[0028] See also Figure 1-Figure 3 In other embodiments, the normal mode or the potential energy recovery mode of the lifting hydraulic cylinder 1 can be switched at any time according to the value detected by the pressure sensor 13.

[0029] Specifically, the port A of the first hydraulically controlled one-way valve 6 is connected to the rod chamber of the lifting hydraulic cylinder 1, and the port B of the first hydraulically controlled one-way valve 6 is connected to the oil inlet circuit 3; the port A of the second hydraulically controlled one-way valve 7 is connected to the main control hydraulic proportional valve 5, and the port B of the second hydraulically controlled one-way valve 7 is connected to the rod chamber of the lifting hydraulic cylinder 1; and the port A of the first hydraulically controlled one-way valve 6 is located in the oil circuit between the rod chamber of the lifting hydraulic cylinder 1 and the second hydraulically controlled one-way valve 7. Furthermore, a balancing valve 12 is also installed in the oil circuit.

[0030] When the weight 15 is lifted, the variable pressure oil source 2 cooperates with the accumulator group to provide power oil for controlling the main hydraulic proportional valve 5 through the oil inlet line 3. The power oil enters the rodless chamber of the lifting hydraulic cylinder 1 under the throttling speed control of the main hydraulic proportional valve 5, thereby pushing the piston rod to move and complete the lifting action. The piston rod lifts the weight 15 through the fixed load 14; in this process, before the fixed load 14 contacts the lifted weight 15, the low-pressure accumulator 16 is used to supply oil, and before contacting the weight 15, the high-pressure accumulator 9 is switched to supply oil. At the same time, during the lifting process, the pressure oil in the rod chamber of the lifting hydraulic cylinder 1 flows to the main hydraulic proportional valve 5 through the second hydraulically controlled one-way valve 7, and then flows back to the oil tank from the return oil line 4.

[0031] When the heavy object 15 is controlled to descend, when the pressure sensor 13 detects that potential energy recovery is not required: the main hydraulic proportional valve 5 is controlled to operate, and the main hydraulic proportional valve 5 changes the oil supply direction of the pressure oil in the main hydraulic proportional valve 5, so that the variable pressure oil source 2 supplies oil to the rod chamber of the lifting hydraulic cylinder 1; at the same time, the pressure oil in the rodless chamber of the lifting hydraulic cylinder 1 flows through the main hydraulic proportional valve 5 to the return oil circuit 4, and returns to the oil tank; thereby, the throttling speed is adjusted by the main hydraulic proportional valve 5 to control the descending action of the lifting hydraulic cylinder 1.

[0032] When the pressure sensor 13 detects that potential energy recovery is required, the first hydraulically controlled one-way valve 6 is controlled to be in an open state through the first control valve 8, so that the pressure oil of the variable pressure oil source 2 and the accumulator group is directly connected to the rodless chamber of the lifting hydraulic cylinder 1 through the oil circuit; due to the setting of the second hydraulically controlled one-way valve 7, the pressure oil in the oil circuit enters the rod chamber of the lifting hydraulic cylinder 1 and cannot enter the B port of the proportional valve, thereby cutting off its flow back to the oil tank;

[0033] Under the dual effects of the pressure oil in the rod chamber of the lifting hydraulic cylinder 1 and the weight 15, the pressure in the rodless chamber of the lifting hydraulic cylinder 1 is increased, and the pressure oil in the rodless chamber flows to the A port of the main control hydraulic proportional valve 5 through the balance valve 12, and then enters the P port of the main control hydraulic proportional valve 5 through the throttling speed control of the main control hydraulic proportional valve 5; the pressure oil entering the P port flows back, and a part of it can directly enter the rod chamber from the first hydraulic control check valve 6; the other part can directly enter the accumulator group for storage, so that the recovery and reuse of gravitational potential energy can be completed simply and conveniently. In addition, the control circuit is green and energy-saving, with simple structure and control and high reliability.

[0034] See also Figure 1-Figure 3 In other embodiments, the high-pressure accumulator 9 is connected to the oil inlet circuit 3 through two third hydraulically controlled one-way valves 11 in sequence; and the A ports of the two third hydraulically controlled one-way valves 11 are connected; the two third hydraulically controlled one-way valves 11 are controlled to be in an open state by the second control valve 10; so that the pressure oil in the high-pressure accumulator 9 can smoothly flow to the oil inlet circuit 3 through the two third hydraulically controlled one-way valves 11. The low-pressure accumulator 16 is installed in the same manner as the high-pressure accumulator 9.

[0035] See also Figure 1-Figure 3 In other embodiments, the second control valve 10 is a two-position four-way electromagnetic reversing valve; the P port of the second control valve 10 is connected to the oil inlet circuit 3, the T port of the second control valve 10 is connected to the oil unloading port L, the A port of the second control valve 10 is disconnected, and the B port of the second control valve 10 is bifurcated and connected to the control oil ports of the two third hydraulically controlled one-way valves 11; when it is necessary to lift a heavy object 15 or recover potential energy, the a end of the second control valve 10 is energized to control the two third hydraulically controlled one-way valves 11; when the high-pressure accumulator 9 and / or the low-pressure accumulator 16 is not needed, the control oil at the two third hydraulically controlled one-way valves 11 is discharged to the oil unloading port L through the T port of the second control valve 10, the third hydraulically controlled one-way valve 11 is closed, and the pressure oil in the two third hydraulically controlled one-way valves 11 can only flow in one direction.

[0036] See also Figure 1-Figure 3 In other embodiments, the main hydraulic proportional valve 5 is a Y-type three-position four-proportional valve, the oil inlet P is connected to the P port of the main hydraulic proportional valve 5, the A port of the main hydraulic proportional valve 5 is connected to the rodless chamber of the lifting hydraulic cylinder 1; the oil return port T is connected to the T port of the main hydraulic proportional valve 5, and the B port of the main hydraulic proportional valve 5 is connected to the rod chamber of the lifting hydraulic cylinder 1. Further, the main hydraulic proportional valve 5 can also be a proportional valve throttle valve, a proportional reversing valve, and other valves capable of reversing and speed regulation, as long as the above functions can be achieved.

[0037] When the a side of the main control hydraulic proportional valve 5 is energized, the oil inlet P is connected to the rod chamber through the main control hydraulic proportional valve 5, and the oil return port T is connected to the rodless chamber through the main control hydraulic proportional valve 5; the oil inlet P allows pressurized oil to flow into the rod chamber, and the pressurized oil in the rodless chamber is discharged through the oil return port T; at this time, the potential energy is not recovered, which is the normal control mode.

[0038] When the b side of the main control hydraulic proportional valve 5 is energized, the oil inlet P is connected to the rodless chamber through the main control hydraulic proportional valve 5, and the oil return port T is connected to the rod chamber through the main control hydraulic proportional valve 5; so that the oil inlet P can flow pressurized oil into the rodless chamber, thereby lifting the fixed load 14 and the heavy object 15;

[0039] In the potential energy recovery mode, the b side of the main hydraulic proportional valve 5 is also energized. Since the pressure oil enters the rod chamber, under the dual action of the weight 15 and the rod chamber, the pressure oil in the rodless chamber increases and is higher than the P port pressure of the main hydraulic proportional valve 5. In this way, the pressure oil in the rodless chamber passes through the A port of the main hydraulic proportional valve 5, enters the P port of the main hydraulic proportional valve 5 after throttling and speed regulation, and then returns to the high-pressure accumulator 9 and / or the low-pressure accumulator 16 through the oil inlet line 3 for recovery and storage.

[0040] When the main control hydraulic proportional valve 5 is in the middle position, the oil inlet P is disconnected from the rod chamber and the rodless chamber of the lifting hydraulic cylinder 1, and the rod chamber and the rodless chamber of the lifting hydraulic cylinder 1 are connected to the oil return port T through the main control hydraulic proportional valve 5, and the lifting hydraulic cylinder 1 stops working.

[0041] See also Figure 1-Figure 3 In other embodiments, the first control valve 8 is a Y-type three-position four-way solenoid reversing valve; the P port of the first control valve 8 is connected to the oil inlet circuit 3, and the T port of the first control valve 8 is connected to the oil return circuit 4 or the leakage port L; the A port of the first control valve 8 is connected to the control oil port of the first hydraulically controlled one-way valve 6; and the B port of the first control valve 8 is connected to the control oil port of the second hydraulically controlled one-way valve 7.

[0042] When the potential energy of the fixed load 14 and the heavy object 15 needs to be recovered, the b side of the first control valve 8 is controlled to be energized, so that the oil inlet circuit 3 is connected to the control oil port of the first hydraulically controlled one-way valve 6 through the first control valve 8, and the pressure oil in the oil inlet circuit 3 controls the first hydraulically controlled one-way valve 6 to be in an open state, thereby connecting the rod chamber and the accumulator group of the lifting hydraulic cylinder 1. Specifically, the lifting hydraulic cylinder 1 is an asymmetric hydraulic cylinder.

[0043] The working principle and use process of this utility model:

[0044] Lifting of heavy objects: When it is necessary to lift a heavy object 15, the variable pressure oil source 2 cooperates with the accumulator group to provide power oil for controlling the main hydraulic proportional valve 5 through the oil inlet line 3. The power oil enters the rodless chamber of the lifting hydraulic cylinder 1 under the throttling speed control of the main hydraulic proportional valve 5, thereby pushing the piston rod to move and complete the lifting action. The piston rod lifts the heavy object 15 by fixing the load 14; at the same time, the pressure oil in the rod chamber of the lifting hydraulic cylinder 1 flows to the main hydraulic proportional valve 5 through the return oil line 4; the pressure oil flows to the T port by controlling the B port of the main hydraulic proportional valve 5, and then flows to the oil tank through the return oil line 4.

[0045] And in the lifting process, when the lifting hydraulic cylinder 1 lifts the fixed load 14 alone, the pressure oil in the oil inlet circuit 3 flows to the P port of the second control valve 10, and then controls the a end of the second control valve 10 at the low-pressure accumulator 16 to be energized, so that the pressure oil flows to the B port through the P port of the second control valve 10, so as to control the two third hydraulic control check valves 11 to be in an open state; so that the low-pressure accumulator 16 is connected to the oil inlet circuit 3, and the pressure oil in the low-pressure accumulator 16 enters the rodless chamber of the lifting hydraulic cylinder 1 through the oil inlet circuit 3, providing power for lifting the fixed load 14. Similarly, when the lifting hydraulic cylinder 1 lifts the fixed load 14 and the heavy object 15 at the same time, the a end of the second control valve 10 at the high-pressure accumulator 9 is controlled to be energized, so that the pressure oil in the high-pressure accumulator 9 enters the rodless chamber of the lifting hydraulic cylinder 1 through the oil inlet circuit 3, providing power for lifting the fixed load 14 and the heavy object 15. In this process, before the fixed load 14 contacts the lifted weight 15 , the low-pressure accumulator 16 is used to supply oil. Before contacting the weight 15 , the high-pressure accumulator 9 is switched to supply oil.

[0046] Potential energy recovery mode for descending heavy objects: When the heavy object 15 is lifted, the pressure sensor 13 detects that potential energy recovery is required and switches to the potential energy recovery mode:

[0047] The pressure oil flows to the A port through the P port of the first control valve 8, and then flows to the control oil port of the first hydraulically controlled non-return valve 6, controlling the first hydraulically controlled non-return valve 6 to be in an open state and the second hydraulically controlled non-return valve 7 to be in a closed state, so that the pressure oil in the accumulator group is directly connected to the rod chamber; for this reason, under the dual action of the pressure oil in the rod chamber of the lifting hydraulic cylinder 1 and the weight 15, the pressure in the rodless chamber of the lifting hydraulic cylinder 1 is increased, and the pressure oil in the rodless chamber flows to the A port of the main control hydraulic proportional valve 5 through the balance valve 12; then the b side of the first control valve 8 is controlled to be energized, so that the pressure oil in the rodless chamber passes through the throttling speed control of the main control hydraulic proportional valve 5 and enters the P port of the main control hydraulic proportional valve 5; for this reason, a part of the pressure oil in the rodless chamber of the lifting hydraulic cylinder 1 can directly enter the rod chamber, thereby increasing the pressure of the rodless chamber; the other part can directly enter the accumulator group for storage, thereby simply and conveniently completing the recovery and reuse of gravitational potential energy. The high-pressure accumulator 9 and / or the low-pressure accumulator 16 are selected to be connected to the oil inlet passage 3 according to actual conditions.

[0048] Conventional control mode for lowering heavy objects: When the weight 15 is lifted, the pressure sensor 13 detects that there is no need to recover potential energy, and controls the a side of the main hydraulic proportional valve 5 to be energized, switching to the conventional control mode; the P port of the main hydraulic proportional valve 5 is connected to the B port, and the T port of the main hydraulic proportional valve 5 is connected to the A port; the variable pressure oil source 2 delivers the pressure oil to the P port of the main hydraulic proportional valve 5 through the oil inlet line 3, and then flows to the rod chamber of the lifting hydraulic cylinder 1 through the B port of the main hydraulic proportional valve 5; at the same time, the pressure oil in the rodless chamber flows to the A port of the main hydraulic proportional valve 5, and then flows back to the oil tank through the T port of the main hydraulic proportional valve 5.

[0049] In summary, in the utility model, the conventional control mode and the potential energy recovery and energy saving mode are controlled in parallel through the same set of hydraulic proportional valves, and the two control modes can be switched automatically. In the potential energy recovery mode, the movement of the lifting hydraulic cylinder 1 is controlled while the gravity potential energy is recovered and reused. The hydraulic control system of the utility model is green and energy-saving, and has a simple structure and control and high reliability.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A heavy object lifting potential energy recovery energy-saving hydraulic control circuit, characterized in that: include: A variable pressure oil source, a main control hydraulic proportional valve, a hydraulically controlled one-way valve combination capable of realizing energy recovery, an accumulator group, a lifting hydraulic cylinder, and a pressure sensor for detecting rodless chamber pressure; the accumulator group includes a high-pressure accumulator and a low-pressure accumulator; The oil inlet circuit and oil return circuit of the variable pressure oil source are connected to the hydraulically controlled one-way valve combination and the main control hydraulic proportional valve, the accumulator group is connected to the oil inlet circuit of the variable pressure oil source, the pressure sensor is connected to the rodless chamber oil circuit of the lifting hydraulic cylinder to detect the pressure of the rodless chamber; the hydraulically controlled one-way valve combination controls the rod chamber oil circuit of the lifting hydraulic cylinder; a set of the main control hydraulic proportional valve and the hydraulically controlled one-way valve combination can be used to cooperate to achieve speed control switching between conventional control and potential energy recovery modes without connecting other pipelines in parallel.

2. The energy-saving hydraulic control circuit for heavy object lifting potential energy recovery according to claim 1 is characterized in that: During the descent of the lifting hydraulic cylinder, the pressure oil in the accumulator group can be controlled by the hydraulically controlled one-way valve combination to directly connect to the rod chamber of the lifting hydraulic cylinder, while cutting off the oil path between the rod chamber of the lifting hydraulic cylinder and the T-port return oil of the main control hydraulic proportional valve.

3. The energy-saving hydraulic control circuit for heavy object lifting potential energy recovery according to claim 1 is characterized in that: The hydraulically controlled one-way valve in the hydraulically controlled one-way valve combination is replaced by a two-way cartridge valve.

4. The energy-saving hydraulic control circuit for heavy object lifting potential energy recovery according to claim 1 is characterized in that: The main control hydraulic proportional valve may be a proportional valve throttle valve or a proportional reversing valve.

5. The energy-saving hydraulic control circuit for recovering potential energy of heavy object lifting according to claim 1 is characterized in that: In the potential energy recovery mode, the rise and fall of the lifting hydraulic cylinder are controlled by the same proportional electromagnet.

6. The energy-saving hydraulic control circuit for recovering potential energy of heavy object lifting according to claim 1 is characterized in that: In the potential energy recovery mode, the accumulator group is directly connected to the rod chamber of the lifting hydraulic cylinder, the pressure of the rodless chamber of the lifting hydraulic cylinder is greater than the pressure of the accumulator group, and a part of the rodless chamber pressure oil is recovered into the accumulator group after speed control by the main control hydraulic proportional valve, and the other part directly enters the rod chamber of the lifting hydraulic cylinder.

7. The energy-saving hydraulic control circuit for recovering potential energy of heavy object lifting according to claim 1 is characterized in that: According to the position and control requirements of the lifting hydraulic cylinder, the pressure is adjusted in real time, and multi-level or stepless adjustment can be achieved.

8. The energy-saving hydraulic control circuit for recovering potential energy of heavy object lifting according to claim 1 is characterized in that: According to the value detected by the pressure sensor, the normal mode or the potential energy recovery mode of the lifting hydraulic cylinder can be switched at any time.

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