An energy saving hydraulic system based on accumulators

Abstract

The utility model discloses an energy -conserving hydraulic system based on energy storage device, including hydraulic pump, check valve, energy storage device, pressure detection device, reversing valve device, hydraulic cylinder, first high pressure oil circuit, second high pressure oil circuit and PLC controller, the oil inlet end of hydraulic pump is connected with oil tank, the oil outlet end of hydraulic pump and the import end of check valve all are connected with first high pressure oil circuit, the export end of check valve, energy storage device and the oil inlet end of reversing valve device all are connected with second high pressure oil circuit, the output end of reversing valve device is connected with hydraulic cylinder, pressure detection device sets up in energy storage device inside. In the utility model, the energy storage device can store the oil pressure of the superfluous high pressure oil circuit, and the energy is released when necessary to compensate the pressure in the high pressure oil circuit, so that the intermittent working mode can be used to the hydraulic pump, to reduce the energy consumption and the working loss of equipment, reduce production cost.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic system technology, and in particular relates to an energy-saving hydraulic system based on an energy storage device. Background Technology

[0002] A hydraulic power unit is a technology that uses fluid to transmit power and is widely used in various industries, including automotive, aerospace, factory automation, construction, and heavy machinery. For example, hydraulic systems are widely used to provide power in CNC machining. However, when a CNC machine tool is idle or stopped, the hydraulic pump needs to remain operational so that the equipment can be started from standby at any time. In this case, excess pressure is released by returning hydraulic oil to the tank through a reversing valve, keeping the hydraulic pump in a continuously operating state. This not only consumes a significant amount of electrical energy but also causes the hydraulic pump motor temperature to rise, increasing wear and tear on the pump, leading to a higher failure rate and a shorter lifespan for the equipment. Utility Model Content

[0003] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide an energy-saving hydraulic system based on an energy storage device.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution: An energy-saving hydraulic system based on an energy storage device includes a hydraulic pump, a check valve, an energy storage device, a pressure detection device, a directional valve device, a hydraulic cylinder, a first high-pressure oil circuit, a second high-pressure oil circuit, and a PLC controller. The inlet of the hydraulic pump is connected to an oil tank. The outlet of the hydraulic pump and the inlet of the check valve are both connected to the first high-pressure oil circuit. The outlet of the check valve, the inlet of the energy storage device, and the inlet of the directional valve device are all connected to the second high-pressure oil circuit. The output of the directional valve device is connected to the hydraulic cylinder. The pressure detection device is located inside the energy storage device and is used to detect the internal pressure of the energy storage device. The hydraulic pump, the directional valve device, and the pressure detection device are all electrically connected to the PLC controller.

[0005] Furthermore, the energy storage device includes multiple hydraulic accumulators connected in series, wherein the first-stage hydraulic accumulator is directly connected to the second high-pressure oil circuit, and the remaining hydraulic accumulators are respectively connected to the previous-stage hydraulic accumulator through a first solenoid valve; the pressure detection device includes multiple pressure sensors, which are installed one-to-one inside each hydraulic accumulator, and each pressure sensor and the first solenoid valve are electrically connected to the PLC controller.

[0006] Furthermore, when the hydraulic pump starts working, the PLC controller opens each of the first solenoid valves, and closes each of the first solenoid valves after detecting that the internal pressure value of the last stage hydraulic accumulator reaches a preset first pressure threshold; after the hydraulic pump stops working, when the PLC controller detects that the internal pressure value of a certain hydraulic accumulator is lower than a preset second pressure threshold, it opens the first solenoid valve between that hydraulic accumulator and the next stage hydraulic accumulator; the first pressure threshold is greater than the second pressure threshold.

[0007] Furthermore, all of the hydraulic accumulators are pneumatic accumulators.

[0008] Furthermore, the energy-saving hydraulic system also includes a second solenoid valve and a relief valve. The inlet end of the relief valve is connected to the first high-pressure oil circuit through the second solenoid valve, and the second solenoid valve is electrically connected to the PLC controller. The outlet end of the relief valve is connected to the oil tank through a sixth high-pressure pipe.

[0009] Furthermore, the first high-pressure oil circuit includes a first oil chamber, a first high-pressure pipe, and a second high-pressure pipe. The oil outlet of the hydraulic pump is connected to the first oil chamber through the first high-pressure pipe, the inlet of the one-way valve is connected to the first oil chamber through the second high-pressure pipe, and the second solenoid valve is directly connected to the first oil chamber.

[0010] Furthermore, the second high-pressure oil circuit includes a second oil chamber, an oil circuit connection chamber, and a third high-pressure pipe. The outlet end of the one-way valve and the energy storage device are both directly connected to the oil circuit connection chamber. The oil circuit connection chamber is connected to the second oil chamber through the third high-pressure pipe. The oil inlet end of the reversing valve device is directly connected to the second oil chamber. The oil return end of the reversing valve device is connected to the oil tank through the fifth high-pressure pipe.

[0011] Furthermore, the energy-saving hydraulic system also includes a pressure gauge, which is directly connected to the second oil chamber.

[0012] Furthermore, the energy-saving hydraulic system also includes an oil reservoir, in which a first chamber and a second chamber are formed, the first chamber forming a first oil chamber and the second chamber forming a second oil chamber.

[0013] Furthermore, the oil tank includes a housing with a cavity and a top cover that closes the opening at the top of the housing. The hydraulic pump, oil storage chamber, oil circuit connection chamber, and PLC controller are all fixed on the top cover.

[0014] In this invention, an energy storage device is used to store excess oil pressure in the high-pressure oil circuit when the hydraulic pump is working. When the hydraulic pump stops working or when it is necessary to increase the pressure of the hydraulic cylinder, the energy storage device can release energy to compensate for the pressure in the high-pressure oil circuit. This allows the hydraulic pump to operate intermittently, reducing energy consumption and equipment wear, and lowering production costs. Furthermore, the energy storage device uses multiple hydraulic accumulators connected in series. The next hydraulic accumulator only begins to release energy after the pressure in the previous accumulator has decreased to a certain level, thus achieving staged energy storage and release and ensuring stable changes in system pressure. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of an embodiment of an energy-saving hydraulic system based on an energy storage device according to this utility model.

[0016] Figure 2 This is a structural schematic diagram from another perspective of this embodiment.

[0017] Figure 3 for Figure 2 This is a top view.

[0018] Figure 4 This is a schematic diagram of the oil circuit connection in this embodiment.

[0019] Figure 5 This is a schematic diagram of the electrical connections for a PLC controller.

[0020] The diagrams in the instruction manual are labeled as follows: Hydraulic pump-1; Check valve-2; Energy accumulator-3; Pressure gauge-4; Directional control valve-5; Hydraulic cylinder-6; Second solenoid valve-7; Relief valve-8; PLC controller-10; First high-pressure pipe-11; Second high-pressure pipe-12; Third high-pressure pipe-13; Fourth high-pressure pipe-14; Fifth high-pressure pipe-15; Sixth high-pressure pipe-16; Oil reservoir-17; First oil chamber-17a; Second oil chamber-17b; Oil circuit connection chamber-18; Oil tank-20; Housing-21; Top cover-22; Oil filling hole-23; Liquid level and temperature gauge-24; Roller-25; Hydraulic accumulator-31, 32, 33; First solenoid valve-34, 35; Pressure detection device-91, 92, 93. Detailed Implementation

[0021] The following specific examples illustrate the implementation of this utility model. The illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0022] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 This utility model discloses an energy-saving hydraulic system based on an energy storage device. A preferred embodiment of this energy-saving hydraulic system based on an energy storage device includes a hydraulic pump 1, a one-way valve 2, an energy storage device 3, a pressure detection device, a directional valve device 5, and a hydraulic cylinder 6 (the hydraulic cylinder 6 is in...). Figures 1 to 4 (not shown in the image), first high-pressure oil circuit, second high-pressure oil circuit and PLC controller 10.

[0023] The inlet of the hydraulic pump 1 is connected to the oil tank 20 via the fourth high-pressure pipe 14. The outlet of the hydraulic pump 1 and the inlet of the check valve 2 are both connected to the first high-pressure oil circuit. The outlet of the check valve 2, the inlet of the energy storage device 3, and the reversing valve device 5 are all connected to the second high-pressure oil circuit. The output of the reversing valve device 5 is connected to the hydraulic cylinder 6. In this embodiment, the reversing valve device 5 consists of four electromagnetic reversing valves. The reversing valve device 5 with four electromagnetic reversing valves and its connection method with the hydraulic cylinder 6 are mature existing technologies and will not be described in detail here. The pressure detection device is installed inside the energy storage device 3 and is used to detect the internal pressure of the energy storage device 3. The hydraulic pump 1, the reversing valve device 5, and the pressure detection device are all electrically connected to the PLC controller 10.

[0024] An accumulator is an energy storage device in a hydraulic and pneumatic system. It converts energy in the system into compressed energy or potential energy and stores it at appropriate times. When the system needs it, it converts the compressed energy or potential energy back into hydraulic or pneumatic energy and releases it to replenish the system. During low-speed operation, the flow rate required by the load is less than the hydraulic pump flow rate (pressure holding stage). The excess flow rate from the hydraulic pump is stored in the accumulator. When the load requires a flow rate greater than the hydraulic pump flow rate, fluid is released from the accumulator to compensate for the insufficient flow rate from the hydraulic pump. When the equipment is stopped / standby but still needs to maintain a certain pressure, the hydraulic pump can be stopped, and the accumulator can compensate for system leakage to maintain the system pressure.

[0025] To more precisely control the oil pressure of the hydraulic cylinder 6, the energy storage device 3 may include multiple hydraulic accumulators connected in series. The first-stage hydraulic accumulator is directly connected to the second high-pressure oil circuit, and the remaining hydraulic accumulators are connected to the previous-stage hydraulic accumulator through a first solenoid valve. The pressure detection device includes multiple pressure sensors, which are installed one-to-one inside each hydraulic accumulator. Each pressure sensor and the first solenoid valve are electrically connected to the PLC controller 10.

[0026] In this embodiment, the energy storage device 3 includes three hydraulic accumulators: a first-stage hydraulic accumulator 31, a second-stage hydraulic accumulator 32, and a third-stage hydraulic accumulator 33. All three hydraulic accumulators are preferably pneumatic bladder accumulators. A first solenoid valve 34 connects hydraulic accumulators 31 and 32, and a first solenoid valve 35 connects hydraulic accumulators 32 and 33. Correspondingly, the pressure detection device includes three pressure sensors: pressure sensor 91, pressure sensor 92, and pressure sensor 93. Pressure sensor 91 is located in hydraulic accumulator 31, pressure sensor 92 is located in hydraulic accumulator 32, and pressure sensor 93 is located in hydraulic accumulator 33.

[0027] When hydraulic pump 1 starts working, PLC controller 10 opens first solenoid valves 34 and 35, and detects the pressure in hydraulic accumulators 31, 32, and 33 via pressure sensors 91, 92, and 93, respectively. After detecting that the internal pressure of hydraulic accumulator 33 (the last stage hydraulic accumulator) reaches a preset first pressure threshold, PLC controller 10 closes all first solenoid valves 34 and 35, maintaining the pressure in hydraulic accumulators 32 and 33 at the first pressure threshold. At this time, PLC controller 10 can control hydraulic pump 1 to shut down, and supply pressure to hydraulic cylinder 6 through hydraulic accumulator 31.

[0028] After the hydraulic pump 1 stops working, the PLC controller 10 first detects the pressure in the hydraulic accumulator 31 (i.e., the first-stage hydraulic accumulator) via the pressure sensor 91. When the internal pressure value of the hydraulic accumulator 31 is detected to be lower than the preset second pressure threshold (the first pressure threshold is greater than the second pressure threshold), the first solenoid valve 34 between the hydraulic accumulator 31 and the hydraulic accumulator 32 (i.e., the next-stage hydraulic accumulator after the hydraulic accumulator 31) is opened, so that the hydraulic accumulators 32 and 31 jointly provide pressure to the hydraulic cylinder 6 to maintain hydraulic stability. At this time, the PLC controller 10 detects the pressure in the hydraulic accumulator 32 via the pressure sensor 92.

[0029] When the PLC controller 10 detects that the internal pressure of the hydraulic accumulator 32 is lower than the preset second pressure threshold, it opens the first solenoid valve 35 between the hydraulic accumulator 32 and the hydraulic accumulator 33 (i.e., the next-stage hydraulic accumulator after the hydraulic accumulator 32), allowing the hydraulic accumulators 31, 32, and 33 to jointly provide pressure to the hydraulic cylinder 6, maintaining hydraulic stability. At this time, the PLC controller 10 detects the pressure in the hydraulic accumulator 33 through the pressure sensor 93. When the PLC controller 10 detects that the internal pressure of the hydraulic accumulator 33 is lower than the preset second pressure threshold, it controls the hydraulic pump 1 to start, storing energy for the three hydraulic accumulators (31, 32, 33).

[0030] To facilitate the return of oil from the first high-pressure oil circuit to the oil tank 20, the energy-saving hydraulic system also includes a second solenoid valve 7 and a relief valve 8. The inlet end of the relief valve 8 is connected to the first high-pressure oil circuit via the second solenoid valve 7, and the second solenoid valve 7 is electrically connected to the PLC controller 10. The outlet end of the relief valve 8 is connected via a sixth high-pressure pipe 16 (the sixth high-pressure pipe 16 is in...). Figures 1 to 4 (Not shown in the image) is connected to the oil tank 20. When the PLC controller 10 opens the second solenoid valve 7, the oil in the first high-pressure oil circuit can flow back to the oil tank 20 through the overflow valve 8.

[0031] The first high-pressure oil circuit may include a first oil chamber 17a, a first high-pressure pipe 11, and a second high-pressure pipe 12. The second high-pressure oil circuit may include a second oil chamber 17b, an oil circuit connection chamber 18, and a third high-pressure pipe 13. In this embodiment, the energy-saving hydraulic system further includes an oil reservoir 17, in which a first chamber and a second chamber are formed. The first chamber forms the first oil chamber 17a, and the second chamber forms the second oil chamber 17b.

[0032] The outlet of the hydraulic pump 1 is connected to the first oil chamber 17a via a first high-pressure pipe 11, and the inlet of the check valve 2 is connected to the first oil chamber 17a via a second high-pressure pipe 12. The second solenoid valve 7 is directly connected to the first oil chamber 17a. The outlet of the check valve 2 and the energy storage device 3 are both directly connected to the oil circuit connection chamber 18, which is connected to the second oil chamber 17b via a third high-pressure pipe 13. The inlet of the reversing valve device 5 is directly connected to the second oil chamber 17b. To facilitate the return of oil from the second high-pressure oil circuit to the oil tank 20, the return end of the reversing valve device 5 is connected via a fifth high-pressure pipe 15 (the fifth high-pressure pipe 15 is located in...). Figures 1 to 4 (Not shown in the image) is connected to the oil tank 20.

[0033] To facilitate visual inspection of the oil pressure in the hydraulic cylinder 6, the energy-saving hydraulic system also includes a pressure gauge 4, which can be directly connected to the second oil chamber. In this embodiment, the oil tank 20 includes a housing 21 with a cavity and a top cover 22 that closes the opening at the top of the housing 21. The hydraulic pump 1, oil storage chamber 17, oil circuit connection chamber 18, and PLC controller 10 are all fixed on the top cover 22. In this embodiment, the top cover 22 is also provided with an oil filling hole 23 for filling the oil tank 20 with oil. A liquid level and temperature gauge 24 is provided on the housing 21 for checking the oil temperature in the oil tank 20. Four rollers 25 are provided at the bottom of the housing 21 for moving the energy-saving hydraulic system.

[0034] Taking the CNC machining of a car's intermediate longitudinal beam as an example, the working status of hydraulic pump 1 was measured and recorded using a stopwatch. It was found that the working time of hydraulic pump 1 accounted for only 3.93%, while the downtime of hydraulic pump 1 accounted for 96.07%. That is, the operating time of hydraulic pump 1 was reduced by 96.07%, which greatly reduced power consumption.

[0035] In a comparative test conducted at the same room temperature of 32℃, the average motor temperature of hydraulic pump 1 in the traditional hydraulic station was 57.2℃, while the average motor temperature of hydraulic pump 1 in the energy-saving hydraulic system of this embodiment was 34.8℃. The motor temperature of hydraulic pump 1 in the energy-saving hydraulic system was 8.75% higher than the room temperature, while the temperature of the traditional hydraulic station was reduced by 22.4℃, with a cooling rate of 39.2%.

[0036] In this embodiment, the energy storage device 3 stores excess oil pressure in the high-pressure oil circuit when the hydraulic pump 1 is working. When the hydraulic pump 1 stops working or when the pressure of the hydraulic cylinder needs to be increased, the energy storage device 3 can release energy to compensate for the pressure in the high-pressure oil circuit. This allows the hydraulic pump 1 to operate intermittently without constant operation, reducing energy consumption and equipment wear and tear, and lowering production costs. Furthermore, the energy storage device 3 uses three hydraulic accumulators (31, 32, 33) connected in series. The next hydraulic accumulator only begins to release energy after the pressure in the previous accumulator drops to a certain level. This allows for graded energy storage and release, making it suitable for systems with precise pressure control requirements. For example, in precision machining hydraulic systems, energy in the storage tank can be gradually released according to different stages of machining, ensuring stable system pressure changes.

[0037] The above embodiments only illustrate preferred implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An energy saving hydraulic system based on an accumulator, characterized in that: The system includes a hydraulic pump, a check valve, an energy storage device, a pressure detection device, a directional valve assembly, a hydraulic cylinder, a first high-pressure oil circuit, a second high-pressure oil circuit, and a PLC controller. The inlet of the hydraulic pump is connected to an oil tank. The outlet of the hydraulic pump and the inlet of the check valve are both connected to the first high-pressure oil circuit. The outlet of the check valve, the inlet of the energy storage device, and the inlet of the directional valve assembly are all connected to the second high-pressure oil circuit. The output of the directional valve assembly is connected to the hydraulic cylinder. The pressure detection device is located inside the energy storage device and is used to detect the internal pressure of the energy storage device. The hydraulic pump, the directional valve assembly, and the pressure detection device are all electrically connected to the PLC controller.

2. The energy-saving hydraulic system based on an energy storage device as described in claim 1, characterized in that: The energy storage device includes multiple hydraulic accumulators connected in series. The first-stage hydraulic accumulator is directly connected to the second high-pressure oil circuit, and the remaining hydraulic accumulators are connected to the previous stage hydraulic accumulator through a first solenoid valve. The pressure detection device includes multiple pressure sensors, which are installed one-to-one inside each hydraulic accumulator. Each pressure sensor and the first solenoid valve are electrically connected to the PLC controller.

3. The energy-saving hydraulic system based on an energy storage device as described in claim 2, characterized in that: When the hydraulic pump starts working, the PLC controller opens each of the first solenoid valves and closes all the first solenoid valves after detecting that the internal pressure value of the last stage hydraulic accumulator reaches the preset first pressure threshold. After the hydraulic pump stops working, when the PLC controller detects that the internal pressure value of a certain hydraulic accumulator is lower than the preset second pressure threshold, it opens the first solenoid valve between that hydraulic accumulator and the next stage hydraulic accumulator. The first pressure threshold is greater than the second pressure threshold.

4. The energy-saving hydraulic system based on an energy storage device as described in claim 2, characterized in that: All hydraulic accumulators are pneumatic accumulators.

5. An energy-saving hydraulic system based on an energy storage device as described in any one of claims 1 to 4, characterized in that: The energy-saving hydraulic system also includes a second solenoid valve and a relief valve. The inlet end of the relief valve is connected to the first high-pressure oil circuit through the second solenoid valve, and the second solenoid valve is electrically connected to the PLC controller. The outlet end of the relief valve is connected to the oil tank through the sixth high-pressure pipe.

6. The energy-saving hydraulic system based on an energy storage device as described in claim 5, characterized in that: The first high-pressure oil circuit includes a first oil chamber, a first high-pressure pipe and a second high-pressure pipe. The oil outlet of the hydraulic pump is connected to the first oil chamber through the first high-pressure pipe. The inlet of the one-way valve is connected to the first oil chamber through the second high-pressure pipe. The second solenoid valve is directly connected to the first oil chamber.

7. The energy-saving hydraulic system based on an energy storage device as described in claim 6, characterized in that: The second high-pressure oil circuit includes a second oil chamber, an oil circuit connection chamber, and a third high-pressure pipe. The outlet end of the one-way valve and the energy storage device are directly connected to the oil circuit connection chamber. The oil circuit connection chamber is connected to the second oil chamber through the third high-pressure pipe. The oil inlet end of the reversing valve device is directly connected to the second oil chamber. The oil return end of the reversing valve device is connected to the oil tank through the fifth high-pressure pipe.

8. The energy-saving hydraulic system based on an energy storage device as described in claim 7, characterized in that: The energy-saving hydraulic system also includes a pressure gauge, which is directly connected to the second oil chamber.

9. The energy-saving hydraulic system based on an energy storage device as described in claim 7, characterized in that: The energy-saving hydraulic system also includes an oil reservoir, in which a first chamber and a second chamber are formed. The first chamber forms a first oil chamber, and the second chamber forms a second oil chamber.

10. The energy-saving hydraulic system based on an energy storage device as described in claim 9, characterized in that: The oil tank includes a housing with a cavity and a top cover that closes the opening at the top of the housing. The hydraulic pump, oil storage chamber, oil circuit connection chamber and PLC controller are all fixed on the top cover.

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