Hydraulic system with protection function

Abstract

The utility model discloses a hydraulic system with a protection function. The hydraulic system comprises an oil tank, an oil cylinder, a driving loop and an energy accumulator. The oil cylinder stretches out and contracts to control the entertainment equipment to descend and ascend respectively; a rod cavity of the oil cylinder is connected with the oil tank through the driving loop, the energy accumulator is connected to a rodless cavity of the oil cylinder, and the driving loop is further connected with the energy accumulator. The driving loop is suitable for supplying oil to a rod cavity of the oil cylinder and further suitable for supplementing oil to the energy accumulator. The energy accumulator is suitable for supplying oil to a rodless cavity of the oil cylinder and storing energy through oil in the rodless cavity when the oil cylinder is contracted. The oil cylinder has the beneficial effects that compared with a traditional mode, the energy accumulator is adopted in the rodless cavity of the oil cylinder for closed oil supply, and self-suction difficulty caused by conventional direct oil suction from an oil tank can be avoided; meanwhile, the energy accumulator can supplement oil in a self-adaptive mode to compensate leakage of the oil cylinder, and therefore working safety of the oil cylinder is guaranteed.

Description

Technical Field

[0001] This application relates to the field of hydraulic technology, and in particular to a hydraulic system with protective functions. Background Technology

[0002] For the hydraulic systems of some amusement park rides, such as rotating towers and space shuttles, high speeds, such as 6-8 m / s, are often required depending on the operating conditions, and these rides also have high operating frequencies. If hydraulic cylinders are used directly to achieve these speed requirements, the manufacturing process of the cylinders must be extremely sophisticated. However, even with highly sophisticated cylinders, frequent oil leaks often occur due to the harsh working environment of amusement rides; this compromises the operational safety of the rides. Utility Model Content

[0003] One objective of this application is to provide a hydraulic system with protective functions that can solve at least one of the defects in the aforementioned background art.

[0004] To achieve at least one of the above objectives, the technical solution adopted in this application is as follows: a hydraulic system with protective function, comprising an oil tank, an oil cylinder, a drive circuit, and an accumulator; the oil cylinder extends and retracts to control the descent and elevation of the entertainment device, respectively; the rod chamber of the oil cylinder is connected to the oil tank via the drive circuit, the accumulator is connected to the rodless chamber of the oil cylinder, and the drive circuit is also connected to the accumulator; the drive circuit is adapted to supply oil to the rod chamber of the oil cylinder, and the drive circuit is also adapted to replenish oil to the accumulator; the accumulator is adapted to supply oil to the rodless chamber of the oil cylinder, and the accumulator is adapted to store energy through the oil in the rodless chamber when the oil cylinder retracts.

[0005] Preferably, the drive circuit includes an oil supply branch, a balance branch, a pilot branch, a replenishment branch, and a servo directional valve V7; the pilot branch is used for pilot control of the servo directional valve V7; the inlet of the servo directional valve V7 is connected to the oil tank through the oil supply branch, and the return port of the servo directional valve V7 is connected to the oil tank; one end of the balance branch is connected to the rod chamber of the cylinder, and the other end is connected to the servo directional valve V7; the servo directional valve and the accumulator are connected through the replenishment branch. Connection; when the cylinder retracts, the pilot branch controls the servo directional valve V7, and the oil supply branch is adapted to deliver oil from the oil tank to the rod chamber of the cylinder through the balance branch; when the cylinder extends, the pilot branch controls the servo directional valve V7, and the balance branch is adapted to directly return the oil from the rod chamber of the cylinder to the oil tank from the return port of the servo directional valve V7; the oil replenishment branch is adapted to replenish oil according to the remaining oil in the accumulator until a set amount is reached.

[0006] Preferably, the oil replenishment branch includes a pressure sensor and a solenoid ball valve V11. The pressure sensor is connected to the accumulator, the input end of the solenoid ball valve V11 is connected to the oil supply branch, and the output end of the solenoid ball valve V11 is connected to the accumulator. The pressure sensor is used to monitor the pressure of the accumulator in real time, and the solenoid ball valve V11 activates the oil replenishment circuit based on the monitoring results of the accumulator. When the accumulator replenishes oil, the rod chamber of the cylinder maintains pressure under the drive of the drive circuit.

[0007] Preferably, the oil supply branch includes a first oil pump, an overflow valve V1, a solenoid ball valve V3, and a check valve V2; the input end of the first oil pump extends to the oil tank, the output end of the first oil pump is connected to the servo directional valve V7 through the check valve V2, and the output end of the first oil pump is also connected to the oil tank through the overflow valve V1 connected in parallel; one end of the solenoid ball valve V3 is connected between the check valve V2 and the servo directional valve V7, and the other end is connected to the oil tank.

[0008] Preferably, the balancing branch includes a balancing valve V9 and an overflow valve V12; the balancing valve V9 is connected to the servo directional valve V7, and the overflow valve V12 is connected in parallel between the rod chamber of the hydraulic cylinder and the servo directional valve V7.

[0009] Preferably, the pilot branch includes a second oil pump, a solenoid directional valve V6, and a relief valve V13; the output end of the second oil pump is connected to the pilot end of the servo directional valve V7 through the solenoid directional valve V6, and the input end of the second oil pump extends into the oil tank; the output end of the second oil pump is also connected to the oil tank through the relief valve V13 connected in parallel.

[0010] Preferably, the balance valve V9 adopts a pilot control structure; the pilot branch also includes a solenoid directional valve V5, and the output end of the second oil pump is also connected to the pilot end of the balance valve V9 through the solenoid directional valve V5.

[0011] Preferably, the hydraulic system further includes an emergency circuit connected to the rod chamber of the cylinder, the emergency circuit being adapted to return the oil in the rod chamber of the cylinder to the oil tank during the return phase of the entertainment device or in the event of a failure of the drive circuit.

[0012] Preferably, the emergency circuit includes a speed control valve V8 and a solenoid ball valve V4 connected in series; the emergency circuit is adapted to control the extension speed of the hydraulic cylinder by controlling the opening of the speed control valve V8.

[0013] Compared with the prior art, the beneficial effects of this application are as follows:

[0014] Compared to traditional methods, the rodless chamber of the cylinder in this application uses an accumulator for closed-loop oil supply, which avoids the self-priming difficulties caused by directly drawing oil from the oil tank. At the same time, the accumulator can adaptively replenish oil to compensate for cylinder leakage, thereby ensuring the safe operation of the cylinder. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this application.

[0016] In the diagram: oil tank 1, first oil pump 2, second oil pump 3, adapter 4, oil cylinder 100, entertainment equipment 200, damper 300, accumulator 400. Detailed Implementation

[0017] The present application will now be further described in conjunction with specific embodiments. It should be noted that, in the description of this specification, the use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0018] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.

[0019] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0020] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0023] One preferred embodiment of this application, such as Figure 1As shown, a hydraulic system with protective functions includes an oil tank 1, an oil cylinder 100, a drive circuit, an accumulator 400, and an emergency circuit. The oil cylinder 100 is generally installed vertically with its rod chamber facing upwards, which improves its operational safety. The piston rod of the oil cylinder 100 is typically connected to the entertainment device 200 via a force-saving mechanism, allowing the entertainment device 200 to be raised and lowered with a relatively small driving force. Specifically, the oil cylinder 100 can control the lowering and raising of the entertainment device 200 by extending and retracting the piston rod.

[0024] The rod chamber of the hydraulic cylinder 100 is connected to the oil tank 1 via a drive circuit and an emergency circuit. The accumulator 400 is connected to the rodless chamber of the hydraulic cylinder 100. The drive circuit can supply oil to the rod chamber of the hydraulic cylinder 100 to drive the hydraulic cylinder 100 to retract, and the accumulator 400 can supply oil to the rodless chamber of the hydraulic cylinder 100 to drive the hydraulic cylinder 100 to extend. The emergency circuit can return the oil in the rod chamber of the hydraulic cylinder 100 to the oil tank 1 during the return phase of the entertainment device 200 or in the event of a drive circuit failure. The accumulator 400 can store energy through the oil in the rodless chamber when the hydraulic cylinder 100 retracts.

[0025] It is understandable that there are various force-saving mechanisms connecting the piston rod of the hydraulic cylinder 100 to the amusement device 200, the most common being pulley blocks. During operation, the amusement device 200 includes a normal ascending phase and a return phase. Taking the common "space shuttle" amusement facility as an example, its ascending phase is a continuous process of rising and falling, with the height of the ascending phase being greater than the height of the descending phase, causing the overall height of the amusement device 200 to continuously increase until it reaches its highest position and then returns to its original position. Traditionally, the hydraulic system control of the amusement device 200 in the return phase uses the same circuit as the descending phase in the ascending phase, i.e., the drive circuit. Because the return phase lasts a long time and has a large impact, it may cause the hoses used for oil supply in the hydraulic system to burst. Therefore, this embodiment sets up an emergency circuit. The emergency circuit can separate the control circuits for the ascending and return phases of the amusement device 200, allowing the oil in the rod chamber of the hydraulic cylinder 100 to flow back to the oil tank 1 through the emergency circuit during the return phase. This reduces the impact force on the drive circuit, thereby ensuring the safety of the entire hydraulic system. Meanwhile, when the drive circuit fails, the entertainment equipment 200 can also achieve safe landing by returning oil through the emergency circuit; however, when the entertainment equipment 200 adopts the traditional control method, it will be unable to return oil to the rod chamber of the cylinder 100 when the drive circuit fails, which will cause the entertainment equipment 200 to fail to land.

[0026] Meanwhile, in this embodiment, the oil supply to the rodless chamber of cylinder 100 is provided by a separate accumulator 400. Since the pressure requirement of the rodless chamber of cylinder 100 is relatively small, a low-pressure accumulator can be used for accumulator 400. Compared with the traditional method of directly supplying oil to the rodless chamber of cylinder 100 from the oil tank 1, this simplifies the hydraulic system's oil circuit structure and enables closed-loop adaptive oil supply. That is, accumulator 400 can continuously supply oil to the rodless chamber of cylinder 100. If leakage occurs in cylinder 100, causing a drop in pressure in the rodless chamber, accumulator 400 can automatically replenish oil to cylinder 100. This ensures stable operation of cylinder 100 and guarantees the safe operation of entertainment equipment 200.

[0027] To address the ultimate failure scenario, i.e., when the amusement equipment 200 loses its restraint and falls freely, a damper 300 can be installed directly below the amusement equipment 200. Upon contact with the damper 300, the damper 300 can convert kinetic energy into heat energy for dissipation, thus cushioning the impact and ensuring the amusement equipment 200 safely returns to the ground. Various types of dampers 300 are available, such as spring dampers and pneumatic-hydraulic dampers. Considering the significant impact of the amusement equipment 200, a pneumatic-hydraulic damper is preferred for the damper 300.

[0028] In this embodiment, there are various specific structures for the emergency circuit that can achieve the above functions. For ease of understanding, one of these structures will be described in detail below. Figure 1 As shown, the emergency circuit includes a speed control valve V8 and a solenoid ball valve V4 connected in series; when the entertainment equipment 200 is returned to its original position, the emergency circuit can control the extension speed of the hydraulic cylinder 100 by controlling the opening of the speed control valve V8.

[0029] It should be understood that the return process of the entertainment device 200 is a process of speed change. That is, the initial return speed is relatively fast, but after reaching a set distance from the ground, the return speed of the entertainment device 200 needs to decrease until the speed is exactly zero when the entertainment device 200 reaches the ground. The change in the return speed of the entertainment device 200 corresponds to the change in the unit flow rate of the oil return in the rod chamber of the hydraulic cylinder 100.

[0030] The specific structure and working principle of the speed control valve V8 are well known to those skilled in the art, and therefore will not be described in detail here. Generally speaking, the speed control valve V8 is a combination valve consisting of a differential pressure reducing valve and a throttle valve connected in series. The throttle valve is used to regulate the flow rate, while the differential pressure reducing valve automatically compensates for the influence of load changes, keeping the pressure difference before and after the throttle valve constant, thereby eliminating the influence of load changes on the flow rate. Therefore, during the return phase of the entertainment equipment 200, the return speed of the entertainment equipment 200 is controlled by first increasing and then decreasing the opening of the throttle valve.

[0031] During the rising phase of the entertainment device 200, to ensure its safe operation, the emergency circuit needs to be completely shut off. At this time, the opening of the speed control valve V8 can be adjusted to zero. However, based on the operating characteristics of the speed control valve V8, its shut-off performance under high pressure is not excellent. Therefore, in this embodiment, an electromagnetic ball valve V4 is added to the emergency circuit. The specific structure and working principle of the electromagnetic ball valve V4 are well known to those skilled in the art and will not be described in detail here. During the rising phase of the entertainment device 200, the electromagnetic ball valve V4 can control the shut-off of the emergency circuit to prevent the oil in the rod chamber of the cylinder 100 from flowing back through the emergency circuit. During the return phase of the entertainment device 200, the electromagnetic ball valve V4 can be opened under electromagnetic control to allow the oil in the rod chamber of the cylinder 100 to flow back to the oil tank 1 along the emergency circuit.

[0032] In this embodiment, as described above, the accumulator 400 can store energy by drawing in oil from the rodless chamber when the cylinder 100 retracts. However, considering the leakage compensation of the accumulator 400 to the cylinder 100, the remaining oil in the accumulator 400 will gradually decrease with increasing working time. When it reaches a certain limit, it may affect the working performance of the accumulator 400. Therefore, in this embodiment, the hydraulic system also includes a replenishment branch connected to the accumulator 400. The replenishment branch can replenish oil to a set amount based on the remaining oil in the accumulator 400.

[0033] Specifically, there are various structures for the oil replenishment branch that can achieve the above functions. For ease of understanding, one such structure will be explained in detail below. Figure 1 As shown, the oil replenishment branch includes a pressure sensor and a solenoid ball valve V11. The pressure sensor is connected to the accumulator 400 to monitor the pressure of the accumulator 400 in real time. The input end of the solenoid ball valve V11 is connected to the drive circuit, and the output end of the solenoid ball valve V11 is connected to the accumulator 400. When the pressure sensor detects that the working pressure of the accumulator 400 is lower than the set threshold, it can feed back the monitoring result to the solenoid ball valve V11. At this time, the solenoid ball valve V11 can open the oil replenishment circuit according to the monitoring result of the accumulator 400, and then the drive circuit can transport the oil in the oil tank 1 to the accumulator 400 through the oil replenishment branch for oil replenishment.

[0034] It is important to note that since the accumulator 400 is directly connected to the rodless chamber of the cylinder 100, replenishing the accumulator 400 may cause some oil to flow into the rodless chamber of the cylinder 100, potentially causing the cylinder 100 to extend. Therefore, to ensure that replenishing the accumulator 400 does not affect the cylinder 100, the rod chamber of the cylinder 100 can maintain pressure under the drive of the drive circuit during replenishment. This means that the pressures in the rod and rodless chambers of the cylinder 100 remain balanced. It should be understood that maintaining pressure balance between the rod and rodless chambers of the cylinder 100 can be controlled by the drive circuit, which will be described in detail later.

[0035] To further ensure the safe operation of the fuel replenishment branch, such as Figure 1 As shown, the oil replenishment branch also includes an overflow valve V10, one end of which is connected to the outlet of the solenoid ball valve V11, and the other end is connected to the oil tank 1. Thus, when the accumulator 400 is unable to replenish oil, the oil delivered by the oil replenishment branch can flow back to the oil tank 1 along the overflow valve V10.

[0036] In this embodiment, there are various specific structures for the drive circuit that can achieve the above functions. For ease of understanding, one of these structures will be described in detail below. Figure 1 As shown, the drive circuit includes an oil supply branch, a balance branch, a pilot branch, and a servo directional valve V7. The pilot branch is used for pilot control of the servo directional valve V7; the inlet of the servo directional valve V7 is connected to the oil tank 1 through the oil supply branch, and the return port of the servo directional valve V7 is also connected to the oil tank 1; one end of the balance branch is connected to the rod chamber of the cylinder 100, and the other end is connected to the servo directional valve V7. When the cylinder 100 retracts, the oil supply branch, through the control of the servo directional valve V7 by the pilot branch, can deliver oil from the oil tank 1 to the rod chamber of the cylinder 100 through the balance branch; when the cylinder 100 extends, the balance branch, through the control of the servo directional valve V7 by the pilot branch, can directly return the oil from the rod chamber of the cylinder 100 to the oil tank 1 through the return port of the servo directional valve V7.

[0037] It is understandable that electromagnetic control could also be used for the servo directional valve V7. However, considering that the entertainment device 200 is used outdoors and its working environment is relatively harsh, electromagnetic control is more prone to damage than hydraulic pilot control. Therefore, in this embodiment, the servo directional valve V7 adopts a pilot control structure. The servo directional valve V7 can be connected to the oil supply branch through the adapter 4, which ensures that the servo directional valve V7 has sufficient interfaces for connection. During the rising phase of the entertainment device 200, the rising speed of the entertainment device 200 is not constant, and different rising speeds correspond to different pressures. Therefore, in order to ensure the stable operation of the cylinder 100, this embodiment sets up a balancing branch to balance the pressure changes of the cylinder 100 during the rising phase of the entertainment device 200. At the same time, in the aforementioned oil replenishment phase of the accumulator 400, the balancing branch can also balance the pressure of the rod chamber and the rodless chamber of the cylinder 100. For ease of understanding, the structure of each branch of the drive circuit will be described in detail below.

[0038] Specifically, such as Figure 1 As shown, the oil supply branch includes a first oil pump 2, a relief valve V1, a solenoid ball valve V3, and a check valve V2. The input end of the first oil pump 2 extends to the oil tank 1, and the output end of the first oil pump 2 is connected to the servo directional valve V7 through the check valve V2. The output end of the first oil pump 2 is also connected to the oil tank 1 through the parallel relief valve V1. One end of the solenoid ball valve V3 is connected between the check valve V2 and the servo directional valve V7, and the other end is connected to the oil tank 1.

[0039] When the entertainment device 200 is in the rising phase, if the entertainment device 200 needs to move upward, that is, the hydraulic cylinder 100 needs to retract, the first oil pump 2 can pump the oil in the oil tank 1 through the one-way valve V2, the servo reversing valve V7 and the balance valve V9 in sequence into the rod chamber of the hydraulic cylinder 100. At this time, the solenoid ball valve V3 is in the closed state. If the entertainment device 200 needs to move downward, that is, the hydraulic cylinder 100 needs to extend, the accumulator 400 can supply oil to the rodless chamber of the hydraulic cylinder 100. At this time, the solenoid ball valve V3 is in the open state, and then the oil in the rod chamber of the hydraulic cylinder 100 flows back to the oil tank 1 after passing through the balance valve V9, the servo reversing valve V7 and the solenoid ball valve V3 in sequence.

[0040] It should be understood that the specific structure and working principle of the relief valve V1 and the solenoid ball valve V3 are well known to those skilled in the art, and therefore will not be described in detail here. The relief valve V1 is mainly used to return the oil pumped by the first oil pump 2 to the oil tank 1 when the drive circuit fails.

[0041] Specifically, such as Figure 1As shown, the balancing branch includes a balancing valve V9 and a relief valve V12. The balancing valve V9 connects the servo directional valve V7 and the rod chamber of the cylinder 100, while the relief valve V12 is connected in parallel to the rod chamber of the cylinder 100. During the upward movement of the entertainment device 200, if the device needs to move upward, the balancing valve V9 can be opened, allowing the oil passing through the servo directional valve V7 to flow from the balancing valve V9 into the rod chamber of the cylinder 100. If the device needs to move downward, the balancing valve V9 can be adjusted, allowing the oil in the rod chamber of the cylinder 100 to flow back from the balancing valve V9 to the servo directional valve V7.

[0042] It should be noted that the specific structure and working principle of the balance valve V9 and the relief valve V12 are well-known technologies to those skilled in the art, and therefore will not be described in detail here. The function of the relief valve V12 is to directly return the oil supplied by the balance valve V9 or the oil in the rod chamber of the cylinder 100 to the oil tank 1 when a fault occurs in the balance branch.

[0043] Specifically, such as Figure 1 As shown, the pilot branch includes a second oil pump 3, a solenoid directional valve V6, and a relief valve V13. The output of the second oil pump 3 is connected to the pilot end of the servo directional valve V7 via the solenoid directional valve V6, and the input end of the second oil pump 3 extends into the oil tank 1. The output of the second oil pump 3 is also connected to the oil tank 1 via the parallel relief valve V13. When the servo directional valve V7 needs to operate, the solenoid directional valve V6 will be turned on, and the second oil pump 3 will deliver oil to the pilot end of the servo directional valve V7 to control the servo directional valve V7 to switch directions.

[0044] It should be noted that the specific structure and working principle of the electromagnetic directional valve V6 and the relief valve V13 are well-known technologies to those skilled in the art, and therefore will not be described in detail here. The function of the relief valve V13 is to directly return the oil pumped by the second oil pump 3 to the oil tank 1 when a failure occurs in the pilot branch.

[0045] It is understandable that the operating environment of the balance valve V9 is basically the same as that of the servo directional valve V7; therefore, the balance valve V9 also preferably adopts a pilot-operated control structure. Figure 1 As shown, the pilot branch also includes a solenoid directional valve V5. The output end of the second oil pump 3 is also connected to the pilot end of the balance valve V9 through the solenoid directional valve V5. When the balance valve V9 needs to operate, the solenoid directional valve V5 is activated, and the second oil pump 3 delivers oil to the pilot end of the balance valve V9 to control the balance valve V9 to switch positions. The specific structure and working principle of the solenoid directional valve V5 are well known to those skilled in the art, and therefore will not be described in detail here.

[0046] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A hydraulic system with protective function, characterized in that, It includes a fuel tank, a hydraulic cylinder, a drive circuit, and an accumulator; the hydraulic cylinder extends and retracts to control the descent and elevation of the entertainment device, respectively; the rod chamber of the hydraulic cylinder is connected to the fuel tank via the drive circuit, the accumulator is connected to the rodless chamber of the hydraulic cylinder, and the drive circuit is also connected to the accumulator; The drive circuit is adapted to supply oil to the rod chamber of the cylinder, and the drive circuit is also adapted to replenish the accumulator; the accumulator is adapted to supply oil to the rodless chamber of the cylinder, and the accumulator is adapted to store energy through the oil in the rodless chamber when the cylinder contracts.

2. The hydraulic system with protective function as described in claim 1, characterized in that, The drive circuit includes an oil supply branch, a balance branch, a pilot branch, a replenishment branch, and a servo directional valve V7. The pilot branch is used to perform pilot control on the servo directional valve V7. The inlet of the servo directional valve V7 is connected to the oil tank through the oil supply branch, and the return port of the servo directional valve V7 is connected to the oil tank. One end of the balance branch is connected to the rod chamber of the cylinder, and the other end is connected to the servo directional valve V7. The servo directional valve and the accumulator are connected through the replenishment branch. Through the control of the servo reversing valve V7 by the pilot branch, the oil supply branch is adapted to deliver the oil in the oil tank to the rod chamber of the oil cylinder through the balance branch; Through the control of the servo directional valve V7 by the pilot branch, the balance branch is adapted to directly return the oil in the rod chamber of the cylinder from the return port of the servo directional valve V7 to the oil tank. The oil replenishment branch is adapted to replenish oil to a set amount based on the remaining oil volume in the accumulator.

3. The hydraulic system with protective function as described in claim 2, characterized in that, The oil replenishment branch includes a pressure sensor and a solenoid ball valve V11; the pressure sensor is connected to the accumulator, the input end of the solenoid ball valve V11 is connected to the oil supply branch, and the output end of the solenoid ball valve V11 is connected to the accumulator. The pressure sensor is used to monitor the pressure of the accumulator in real time, and the electromagnetic ball valve V11 opens the oil replenishment circuit according to the monitoring results of the accumulator. When the accumulator is replenished with oil, the rod chamber of the oil cylinder is pressure-maintained under the drive of the drive circuit.

4. The hydraulic system with protective function as described in claim 2, characterized in that, The oil supply branch includes a first oil pump, an overflow valve V1, a solenoid ball valve V3, and a check valve V2; the input end of the first oil pump extends to the oil tank, the output end of the first oil pump is connected to the servo directional valve V7 through the check valve V2, and the output end of the first oil pump is also connected to the oil tank through the overflow valve V1 in parallel; one end of the solenoid ball valve V3 is connected between the check valve V2 and the servo directional valve V7, and the other end is connected to the oil tank.

5. The hydraulic system with protective function as described in claim 2, characterized in that, The balance branch includes a balance valve V9 and an overflow valve V12; the balance valve V9 is connected to the servo directional valve V7, and the overflow valve V12 is connected in parallel between the rod chamber of the hydraulic cylinder and the servo directional valve V7.

6. The hydraulic system with protective function as described in claim 5, characterized in that, The pilot branch includes a second oil pump, a solenoid directional valve V6, and a relief valve V13; the output end of the second oil pump is connected to the pilot end of the servo directional valve V7 through the solenoid directional valve V6, and the input end of the second oil pump extends into the oil tank; the output end of the second oil pump is also connected to the oil tank through the relief valve V13 connected in parallel.

7. The hydraulic system with protective function as described in claim 6, characterized in that, The balance valve V9 adopts a pilot control structure; the pilot branch also includes a solenoid directional valve V5, and the output end of the second oil pump is also connected to the pilot end of the balance valve V9 through the solenoid directional valve V5.

8. The hydraulic system with protective function as described in any one of claims 2-7, characterized in that, The hydraulic system also includes an emergency circuit connected to the rod chamber of the cylinder, the emergency circuit being adapted to return the oil in the rod chamber of the cylinder to the oil tank during the return phase of the entertainment device or in the event of a failure of the drive circuit.

9. The hydraulic system with protective function as described in claim 8, characterized in that, The emergency circuit includes a speed control valve V8 and a solenoid ball valve V4 connected in series; the emergency circuit is adapted to control the extension speed of the hydraulic cylinder by controlling the opening of the speed control valve V8.

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