Anti-impact hydraulic closed pump control system and hydraulic mechanical equipment

Abstract

The invention discloses an anti-impact hydraulic closed type pump control system and hydraulic mechanical equipment, the anti-impact hydraulic closed type pump control system comprises a closed type pump set, a power assembly and two anti-impact valve sets arranged in parallel relative to the power assembly, an oil inlet of one anti-impact valve set is connected with the first end of the power assembly, and an oil outlet of the other anti-impact valve set is connected with the second end of the power assembly. The oil inlet of the other anti-impact valve group is connected with the second end of the power assembly; the anti-impact valve set comprises an external control buffer valve, a buffer damper and an energy accumulator, a feedback end and a control end are arranged on the two opposite sides of a valve element of the external control buffer valve respectively, and the control end is provided with a spring used for driving the valve element to move and be closed in the direction towards the feedback end. An oil inlet of the external control buffer valve is provided with a feedback oil way connected with the feedback end and a control oil way connected with the control end, and the buffer damper and the energy accumulator are sequentially arranged on the control oil way. According to the anti-impact hydraulic closed pump control system, pressure impact of the high-pressure side oil way can be weakened, and the pressure of the low-pressure side oil way is prevented from being rapidly reduced.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, and in particular, to an anti-impact hydraulic closed-loop pump control system, and hydraulic mechanical equipment employing the said anti-impact hydraulic closed-loop pump control system. Background Technology

[0002] For hydraulic closed-loop drive systems of engineering machinery such as tunnel boring machine cutterheads, screw conveyors, and chain cutter continuous wall equipment, mining machinery such as tunneling and anchoring machines, agricultural machinery such as cotton harvesters, and special machinery such as snow blowers, the systems are susceptible to sudden load changes, jamming, and start-up conditions during operation. This can easily lead to severe pressure shocks on the high-pressure side of the hydraulic system. At the same time, the impact on the low-pressure side is accompanied by pressure reduction and cavitation, causing damage to the internal plunger structure of the closed-loop pump and motor, thus affecting service life. Therefore, it is necessary to install anti-shock oil circuits in the hydraulic closed-loop drive system to reduce pressure shocks on the high-pressure side of the system, prevent rapid pressure reduction or even cavitation on the low-pressure side of the system, and extend the service life of the system and its hydraulic components.

[0003] However, existing hydraulic systems typically address pressure shock by incorporating a relief valve or accumulator into the system's pressure shock circuit. But due to the short duration and high speed of hydraulic shocks, conventional relief valves cannot respond in time, resulting in relief pressure control failure or significant pressure overshoot. While soft relief valves can achieve a low-pressure start-up response to the instantaneous impact pressure, thus significantly reducing pressure overshoot, they only work for impacts with pressures higher than the spring's set value. They cannot adjust for pressure shocks of different amplitudes. Furthermore, once their structural parameters are determined, the pressure rise slope is fixed and cannot be adjusted, resulting in poor applicability. Secondly, accumulators, as commonly used shock-absorbing components in hydraulic systems, are connected in parallel with the impact oil circuit. The high-pressure nitrogen in the accumulator reaches a balance with the oil pressure, and the free contraction and expansion of nitrogen achieves the effect of "peak shaving and valley leveling". However, in a closed hydraulic system, the oil volume on the high-pressure side circuit and the oil volume on the low-pressure side circuit are in dynamic equilibrium. Adding an accumulator means a significant increase in the total volume of oil on the high-pressure side and a significant decrease in the system's elastic modulus. This results in a significant increase in the oil replenishment flow required by the system at the moment of impact, making it very easy for the low-pressure side pressure to be sucked into cavitation due to insufficient oil replenishment flow, which seriously affects the service life of the closed pump and motor in the system. Summary of the Invention

[0004] The present invention primarily provides an anti-shock hydraulic closed-loop pump control system to solve the technical problem of poor anti-shock performance of existing hydraulic closed-loop pump control systems.

[0005] The present invention also provides a hydraulic mechanical device that employs the above-mentioned anti-impact hydraulic closed-loop pump control system.

[0006] According to one aspect of the present invention, an anti-shock hydraulic closed-loop pump control system is provided, comprising a closed-loop pump assembly and a power assembly. A first end of the closed-loop pump assembly is connected to a first end of the power assembly, and a second end of the closed-loop pump assembly is connected to a second end of the power assembly. The closed-loop pump assembly is used to drive the power assembly to rotate and adjust the speed and direction of the power assembly. The anti-shock hydraulic closed-loop pump control system further comprises two anti-shock valve assemblies arranged in parallel relative to the power assembly. The oil inlet of one anti-shock valve assembly is connected to the first end of the power assembly, and the oil inlet of the other anti-shock valve assembly is connected to the second end of the power assembly.

[0007] The anti-shock valve assembly includes an externally controlled buffer valve, a buffer damper, and an accumulator. The valve core of the externally controlled buffer valve is designed to allow hydraulic oil to flow only in one direction from the inlet to the outlet. The externally controlled buffer valve has a feedback end and a control end on opposite sides of its valve core. The control end is equipped with a spring for driving the valve core to move and close in the direction toward the feedback end. The inlet of the externally controlled buffer valve has a feedback oil circuit connected to the feedback end and a control oil circuit connected to the control end. The buffer damper and the accumulator are sequentially arranged in the control oil circuit in the direction toward the control end.

[0008] Preferably, the anti-impact valve assembly further includes a return check valve arranged in parallel with the buffer damper, the inlet end of the return check valve being connected to the accumulator, and the outlet end of the return check valve being connected to the oil inlet of the externally controlled buffer valve.

[0009] Preferably, the buffer damping is configured as adjustable damping, and the anti-impact hydraulic closed-loop pump control system further includes a pressure detection component and an adjustment component. The pressure detection component is connected to the power component and is used to detect the working pressure of the power component in real time. The adjustment component is connected to the adjustable damping and is used to adjust the adjustable damping according to the detection result of the pressure detection component.

[0010] Preferably, the nitrogen charging pressure of the accumulator is adjustable, and the anti-impact hydraulic closed-loop pump control system further includes a pressure detection component and an adjustment component. The pressure detection component is connected to the power component and is used to detect the working pressure of the power component in real time. The adjustment component is connected to the accumulator and is used to adjust the accumulator according to the detection result of the pressure detection component.

[0011] Preferably, the spring force is adjustable, and the anti-impact hydraulic closed-loop pump control system further includes a pressure detection component and an adjustment component. The pressure detection component is connected to the power component and is used to detect the working pressure of the power component in real time. The adjustment component is connected to the spring and is used to adjust the spring according to the detection result of the pressure detection component.

[0012] Preferably, the closed-loop pump assembly includes a closed-loop pump, and a first overflow valve and a second overflow valve respectively arranged in parallel with respect to the closed-loop pump. The first end of the closed-loop pump is connected to the first end of the power assembly, and the second end of the closed-loop pump is connected to the second end of the power assembly.

[0013] The oil inlet of the first overflow valve is connected to the first end of the closed pump, and the overflow port of the first overflow valve is provided with a first overflow check valve that is disposed toward the second end of the closed pump and connected to the second end of the closed pump.

[0014] The oil inlet of the second overflow valve is connected to the second end of the closed pump, and the overflow port of the second overflow valve is provided with a second overflow check valve that is disposed toward the first end of the closed pump and connected to the first end of the closed pump.

[0015] Preferably, the anti-impact hydraulic closed-loop pump control system further includes a replenishing pump group for outputting hydraulic oil. The closed-loop pump group also includes two replenishing check valves respectively connected to the output end of the replenishing pump group. The outlet end of one of the replenishing check valves is connected to the first end of the closed-loop pump, and the outlet end of the other replenishing check valve is connected to the second end of the closed-loop pump.

[0016] Preferably, the closed-loop pump set includes a flushing oil passage connected to the output end of the replenishing oil pump set and used for flushing the bearings and housing of the closed-loop pump, as well as a flushing damper disposed between the replenishing oil pump set and the flushing oil passage.

[0017] Preferably, the anti-impact hydraulic closed-loop pump control system further includes a flushing valve assembly, which includes a flushing shuttle valve and a flushing overflow valve. The flushing shuttle valve is connected in parallel with the power component and is used to connect the low-pressure side oil circuit of the power component with the flushing overflow valve. The flushing overflow valve is used to connect to the oil tank and allow a portion of the oil in the low-pressure side oil circuit of the power component to flow back to the oil tank through the flushing overflow valve.

[0018] As a second aspect, the present invention also provides a hydraulic mechanical device, including the above-mentioned anti-shock hydraulic closed-loop pump control system.

[0019] The present invention has the following beneficial effects:

[0020] In the anti-shock hydraulic closed-loop pump control system provided by this invention, the anti-shock valve group includes an externally controlled buffer valve, a buffer damper, and an accumulator. When the power unit is in a shock, jamming, or start-up condition, the pressure in the high-pressure side oil circuit rises rapidly and enters the inlet of the corresponding externally controlled buffer valve. Through the feedback oil circuit, the pressure at the feedback end of the externally controlled buffer valve rises rapidly. Through the flow-limiting effect of the buffer damper in the control oil circuit and the buffering effect of the accumulator, the pressure rise rate at the control end of the externally controlled buffer valve is much lower than the pressure rise rate at the feedback end. Furthermore, since the impact pressure at the feedback end is much greater than the spring pressure, at the first moment of impact, the pressure at the feedback end will be greater than the sum of the spring pressure and the pressure in the control oil circuit. This automatically drives the valve core to move towards the control end, allowing some oil in the high-pressure side oil circuit to flow to the low-pressure side oil circuit, greatly reducing the pressure shock in the high-pressure side oil circuit and preventing the closed-loop pump from being damaged. Damage to the assembly and power components under high-pressure impact can be mitigated by replenishing oil to the low-pressure side oil circuit while reducing the impact pressure on the high-pressure side oil circuit. This reduces the system pressure increase rate and significantly reduces the flow difference required to replenish the low-pressure side oil circuit, preventing a rapid drop in pressure or even cavitation in the low-pressure side oil circuit and extending its service life. After a period of buffering from the high-pressure impact, as the accumulator continuously fills with oil and increases the reaction force, the pressure at the control end of the external control buffer valve gradually increases. This gradually pushes the valve core to move towards the feedback end and close, preventing prolonged overflow that could cause system overheating and energy waste. After the high-pressure impact ends, the pressure in the high-pressure side oil circuit drops, and the oil in the accumulator can flow back to the high-pressure side oil circuit, releasing the pressure and balancing the pressure at the feedback and control ends of the external control buffer valve. This allows the system to quickly return to its initial state to cope with the next impact, jamming, or startup conditions.

[0021] Secondly, it should be understood that when the closed-loop pump unit outputs oil to the first end of the power component and returns oil from the second end of the power component, the first end of the power component is the high-pressure side oil circuit, and the second end of the power component is the low-pressure side oil circuit. Similarly, when the power component needs to rotate in the opposite direction, that is, when the closed-loop pump unit outputs oil to the second end of the power component and returns oil from the first end of the power component, the first end of the power component is the low-pressure side oil circuit, and the second end of the power component is the high-pressure side oil circuit. Therefore, both the first and second ends of the power assembly can potentially be converted into high-pressure side oil circuits. This anti-shocking hydraulic closed-loop pump control system includes two anti-shocking valve assemblies connected in parallel relative to the power assembly. The inlet of one anti-shocking valve assembly is connected to the first end of the power assembly, and the inlet of the other anti-shocking valve assembly is connected to the second end of the power assembly. Furthermore, the valve core of the external control buffer valve is designed as a unidirectional structure that only allows hydraulic oil to flow from the inlet to the outlet. When the power assembly rotates forward or backward, the independent anti-shocking valve assembly can provide shock buffering. When the power assembly is in a shock, jamming, or start-up condition, only the anti-shocking valve assembly connected to the high-pressure side oil circuit of the power assembly is active. Compared to using only one anti-shocking valve assembly to prevent shock in both directions, this eliminates the need for an additional check valve to adjust the inlet direction and avoids the influence of unidirectional flow. The impact of valves on response speed is significant, especially in high-power hydraulic systems where the hydraulic flow in the pipeline is extremely large, requiring larger check valves. Consequently, the response speed of the check valves is further reduced, further affecting the impact suppression effect. Furthermore, if oil is introduced into buffer devices such as accumulators through check valves, the oil cannot flow in reverse. After the impact ends, the buffer device remains under high pressure and cannot release the pressure, making it impossible to achieve the buffering and suppression effect for the next impact in a short period of time. This application, by setting two anti-impact valve groups, can directly respond to impact pressure fluctuations in two directions without the need for additional check valve interference. This effectively ensures the impact suppression effect, and after the high-pressure impact ends, the high-pressure oil in the accumulator can directly flow back to the high-pressure side oil circuit, realizing the pressure release of the accumulator. This can meet the effective buffering and suppression effect for continuous and multiple impacts.

[0022] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the anti-impact hydraulic closed-loop pump control system provided in an embodiment of the present invention;

[0025] Figure 2 for Figure 1 The diagram shows the structure of the anti-impact valve group in the anti-impact hydraulic closed-loop pump control system.

[0026] Figure 3 for Figure 2 A schematic diagram of another embodiment of the anti-impact valve assembly shown;

[0027] Figure 4 for Figure 1 The diagram shows the structure of the closed-loop pump unit in the anti-shock hydraulic closed-loop pump control system.

[0028] Figure 5 for Figure 1 The diagram shows the structure of the replenishing pump unit in the anti-shock hydraulic closed-loop pump control system.

[0029] Figure 6 for Figure 1 The diagram shows the structure of the flushing valve assembly in the anti-impact hydraulic closed-loop pump control system.

[0030] Figure 7 for Figure 1 The diagram shows the pressure change of the power component in the anti-shock hydraulic closed-loop pump control system under shock conditions.

[0031] Figure 8 for Figure 1 The diagram shows the pressure change of the power component in the anti-shock hydraulic closed-loop pump control system under jamming conditions.

[0032] Figure 9 for Figure 1 The diagram shows the pressure change of the power component in the anti-shock hydraulic closed-loop pump control system under startup conditions.

[0033] Legend:

[0034] 1. Closed-loop pump unit; 11. Closed-loop pump; 12. First relief valve; 13. Second relief valve; 14. First relief check valve; 15. Second relief check valve; 16. Replenishment check valve; 17. Flushing oil circuit; 18. Flushing damping; 19. Starter motor;

[0035] 2. Power components; 21. Hydraulic motor;

[0036] 3. Anti-impact valve assembly; 31. Externally controlled buffer valve; 311. Valve core; 312. Feedback end; 313. Control end; 314. Spring; 315. Feedback oil circuit; 316. Control oil circuit; 32. Buffer damping; 33. Accumulator; 34. Return check valve;

[0037] 4. Oil replenishment pump assembly; 41. Oil replenishment motor; 42. Oil replenishment pump; 43. Oil replenishment overflow valve;

[0038] 5. Flushing valve assembly; 51. Flushing shuttle valve; 511. First switching end; 512. Second switching end; 52. Flushing overflow valve. Detailed Implementation

[0039] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0040] Those skilled in the art will understand that, unless specifically stated otherwise, the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, components, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or combinations thereof. It should be understood that when we say a component is "connected" to another component, it can be directly connected to the other component or connected via an intermediate component. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items. The terms "first" and "second," etc., in this specification and claims are used to distinguish different objects, not to describe a particular order.

[0041] Figures 1 to 9 The present invention provides an anti-impact hydraulic closed-loop pump control system, which is a hydraulic power system in which hydraulic oil circulates in a closed loop. Compared with an open hydraulic system, it does not require frequent oil replenishment, reduces oil leakage and external pollution, improves transmission efficiency, has a simple and compact structure, and is easy to control. The reciprocating motion of the actuator can be achieved through the forward and reverse flow of oil in the closed loop. It is suitable for hydraulic machinery and equipment with high space and efficiency requirements. Furthermore, the anti-impact hydraulic closed-loop pump control system can effectively buffer and suppress impacts, weaken the impact pressure on the high-pressure side oil circuit, and prevent the pressure on the low-pressure side oil circuit from dropping rapidly or even cavitating, thus extending service life.

[0042] Please combine Figure 1 and Figure 2The anti-impact hydraulic closed-loop pump control system includes a closed-loop pump group 1 and a power component 2. The first end of the closed-loop pump group 1 is connected to the first end of the power component 2, and the second end of the closed-loop pump group 1 is connected to the second end of the power component 2. The closed-loop pump group 1 is used to drive the power component 2 to rotate and adjust the speed and direction of the power component 2.

[0043] Furthermore, the anti-shocking hydraulic closed-loop pump control system also includes two anti-shocking valve groups 3 arranged in parallel with the power component 2. The inlet of one anti-shocking valve group 3 is connected to the first end of the power component 2, and the inlet of the other anti-shocking valve group 3 is connected to the second end of the power component 2. The anti-shocking valve group 3 includes an externally controlled buffer valve 31, a buffer damper 32, and an accumulator 33. The valve core 311 of the externally controlled buffer valve 31 is configured as a unidirectional structure that only allows hydraulic oil to flow in one direction from the inlet to the outlet. The externally controlled buffer valve 31 has a feedback end 312 and a control end 313 on opposite sides of its valve core 311. The control end 313 is provided with a spring 314 for driving the valve core 311 to move and close in the direction toward the feedback end 312. The inlet of the externally controlled buffer valve 31 has a feedback oil circuit connected to the feedback end 312. The feedback oil circuit 315 is used to introduce hydraulic oil into the feedback terminal 312 and apply a force to the valve core 311 to move and open in the direction toward the control terminal 313. The control oil circuit 316 is used to introduce oil into the control terminal 313 and apply a force to the valve core 311 to move and close in the direction toward the feedback terminal 312. The buffer damper 32 and the accumulator 33 are sequentially arranged on the control oil circuit 316 in the direction toward the control terminal 313.

[0044] Specifically, in the anti-impact hydraulic closed-loop pump control system, the anti-impact valve group 3 includes an external control buffer valve 31, a buffer damper 32, and an accumulator 33. When the power assembly 2 is in an impact, jamming, or start-up condition, the pressure in its high-pressure side oil circuit rises rapidly and enters the inlet of the corresponding external control buffer valve 31. Through the feedback oil circuit 315, the pressure at the feedback end 312 of the external control buffer valve 31 rises rapidly. Through the flow restriction effect of the buffer damper 32 on the control oil circuit 316 and the buffering effect of the accumulator 33, the pressure rise rate at the control end 313 of the external control buffer valve 31 is much lower than the pressure rise rate at the feedback end 312. Furthermore, since the impact pressure at the feedback end 312 is much greater than the pressure of the spring 315, at the first moment of impact, the pressure at the feedback end 312 will be greater than the sum of the spring 314 pressure and the pressure of the control oil circuit 316. This automatically drives the valve core 311 to move and open in the direction towards the control end 313, allowing some oil in the high-pressure side oil circuit to flow to the low-pressure side oil circuit, greatly reducing the impact. The pressure shock of the high-pressure side oil circuit prevents damage to the closed pump unit 1 and power component 2 under high pressure shock. While weakening the shock pressure of the high-pressure side oil circuit, it can also replenish oil to the low-pressure side oil circuit, reducing the system pressure increase rate, thereby significantly reducing the flow difference that needs to be replenished to the low-pressure side oil circuit. This effectively prevents the pressure of the low-pressure side oil circuit from dropping rapidly or even cavitating, thus extending its service life. After the high-pressure shock buffering period, as the accumulator 33 continuously fills with oil and continuously increases the reaction force, the pressure at the control end 313 of the external control buffer valve 31 gradually increases, thereby gradually pushing the valve core 311 to move and close in the direction towards the feedback end 312. This avoids long-term overflow causing system heat generation and energy waste. After the high-pressure shock ends, the pressure of the high-pressure side oil circuit drops, and the oil in the accumulator 33 can flow back to the high-pressure side oil circuit, realizing pressure release. This balances the pressure at the feedback end 312 and the control end 313 of the external control buffer valve 31, quickly restoring the initial state to cope with the next shock, jamming, or start-up conditions.

[0045] Secondly, it should be understood that when the closed-loop pump unit 1 outputs oil to the first end of the power assembly 2 and returns oil from the second end of the power assembly 2, the first end of the power assembly 2 is the high-pressure side oil circuit, and the second end of the power assembly 2 is the low-pressure side oil circuit. Similarly, when the power assembly 2 needs to rotate in the opposite direction, that is, when the closed-loop pump unit 1 outputs oil to the second end of the power assembly 2 and returns oil from the first end of the power assembly 2, the first end of the power assembly 2 is the low-pressure side oil circuit, and the second end of the power assembly 2 is the high-pressure side oil circuit. Therefore, both the first and second ends of the power assembly 2 can potentially be converted into high-pressure side oil circuits. This anti-shocking hydraulic closed-loop pump control system includes two anti-shocking valve groups 3 connected in parallel with the power assembly 2. The inlet of one anti-shocking valve group 3 is connected to the first end of the power assembly 2, and the inlet of the other anti-shocking valve group 3 is connected to the second end of the power assembly 2. Furthermore, the valve core 311 of the external control buffer valve 31 is designed to allow hydraulic oil to flow only from the inlet to the outlet in a unidirectional structure. When the power assembly 2 rotates forward or backward, the independent anti-shocking valve group 3 can provide shock buffering. When the power assembly 2 is in a shock, jamming, or start-up condition, only the anti-shocking valve group 3 connected to the high-pressure side oil circuit of the power assembly functions. Compared to using only one anti-shocking valve group to prevent shock in both directions, there is no need to additionally install a check valve to adjust the oil inlet direction. The response speed is not affected by check valves, especially for high-power hydraulic systems where the hydraulic flow in the pipeline is extremely large, requiring larger check valves. Consequently, the response speed of the check valves is further reduced, further affecting the impact suppression effect. Furthermore, if oil is introduced into buffer devices such as accumulators through check valves, the oil cannot flow in reverse. After the impact ends, the buffer device remains under high pressure and cannot release the pressure, making it impossible to achieve the buffering and suppression effect for the next impact in a short period of time. However, this application sets two anti-impact valve groups 3, which can directly respond to impact pressure fluctuations in two directions without the need for additional check valve interference. This effectively ensures the impact suppression effect. After the high-pressure impact ends, the high-pressure oil in the accumulator 33 can directly flow back to the high-pressure side oil circuit, realizing the pressure release of the accumulator 33. This can meet the effective buffering and suppression effect for continuous and multiple impacts.

[0046] Please combine Figures 7 to 9 Through testing and verification, under impact conditions, jamming conditions, or start-up conditions, the high-pressure side oil circuit and low-pressure side oil circuit of the anti-impact hydraulic closed-loop pump control system, when equipped with the anti-impact valve group 3, can effectively suppress pressure fluctuations compared to the case without the anti-impact valve group 3, thus achieving a buffer protection function. Specifically, in Figure 7The diagram illustrates the pressure change of the power component 2 in the anti-shock hydraulic closed-loop pump control system under shock conditions. When subjected to shock, the externally controlled buffer valve 31 is opened by the shock pressure, allowing some oil in the high-pressure side oil circuit to flow to the low-pressure side oil circuit. This significantly reduces the pressure shock in the high-pressure side oil circuit and prevents a rapid decrease in pressure in the low-pressure side oil circuit, resulting in smoother pressure fluctuations compared to when there is no anti-shock valve assembly 3. Figure 8 The diagram illustrates the pressure change of the power component 2 in the anti-impact hydraulic closed-loop pump control system under jamming conditions. When jamming occurs, the power component 2 becomes stuck and cannot rotate. Similarly, the pressure in the high-pressure side oil circuit rises rapidly, driving the externally controlled buffer valve 31 to open, allowing some oil in the high-pressure side oil circuit to flow to the low-pressure side oil circuit, achieving a buffering effect and making the pressure change smoother. Figure 9 The diagram shows the pressure change of the power component 2 in the anti-shock hydraulic closed-loop pump control system under startup conditions. Under startup conditions, due to factors such as the inertia of the working mechanism and the conversion of dynamic and static friction, the initial load of the power component 2 is relatively large. Therefore, the pressure of the high-pressure side oil circuit is relatively large at the moment of startup. The anti-shock valve group 3 can also achieve a buffering effect, diverting part of the oil in the high-pressure side oil circuit to the low-pressure side oil circuit, reducing the pressure shock of the high-pressure side oil circuit and replenishing the oil in the low-pressure side oil circuit, making the startup of the power component 2 smoother.

[0047] like Figure 2 As shown, preferably, the anti-impact valve assembly 3 further includes a return check valve 34, which is arranged in parallel with the buffer damper 32. The inlet end of the return check valve 34 is connected to the accumulator 33, and the outlet end of the return check valve 34 is connected to the oil inlet of the external control buffer valve 31.

[0048] The working principle of the return check valve 34 is as follows: when the pressure at the inlet of the externally controlled buffer valve 31 rises rapidly, the backflow check valve 34 prevents the high-pressure oil from entering the accumulator 33 only along the buffer damper 32. Thus, the flow restriction and buffering effect are achieved through the cooperation of the buffer damper 32 and the accumulator 33. When the pressure at the inlet of the externally controlled buffer valve 31 returns to a stable level, the oil in the accumulator 33 can quickly return to the high-pressure side oil circuit along the return check valve 34. The return process does not need to pass through the buffer damper 3, which realizes rapid oil replenishment to the high-pressure side oil circuit and also quickly releases the pressure of the accumulator 33, quickly restoring the initial state in order to cope with the next impact, jamming or start-up conditions.

[0049] Furthermore, the buffer damper 32 is a fixed damper with a fixed resistance value. The appropriate specification of the buffer damper 32 can be selected according to the specific application scenario of the power component 2. It has a simple and efficient structure, low cost and long service life.

[0050] like Figure 3 As shown, in another embodiment, the buffer damper 32 can also be configured as an adjustable damper, the resistance of which is adjustable. The anti-impact hydraulic closed-loop pump control system further includes a pressure detection component (not shown in the figure, the same below) and an adjustment component (not shown in the figure, the same below). The pressure detection component is connected to the power component 2 and is used to detect the working pressure of the power component 2 in real time. The adjustment component is connected to the adjustable damper and is used to adjust the adjustable damper according to the detection result of the pressure detection component, so that the resistance of the adjustable damper can more accurately adapt to the different working pressures of the power component 2. Taking the cutterhead drive system of a tunnel boring machine as an example, its working pressure range varies greatly under different geological conditions. Under light load conditions, the working pressure of the high-pressure side oil circuit of the cutterhead drive system is between 65-80 bar, while under medium load conditions it is between 100-125 bar, under heavy load conditions it can reach between 145-190 bar, and under jammed conditions it can reach 300 bar. At the same time, the impact waveforms caused by different gravels, boulders, and alternating soft and hard rocks are also different. Therefore, a single hardware parameter setting is difficult to fully adapt to the different impact characteristics caused by different geological environments. At this time, the buffer damper 32 adopts adjustable damping and automatically adjusts the resistance according to the different working pressure of the power component 2, so that it can better adapt to the different impact characteristics caused by different geological environments and achieve effective control of pressure fluctuations.

[0051] Specifically, the adjustment component is used to reduce the resistance of the adjustable damper when the pressure impact of the power component 2 is small, so as to reduce the pressure waveform gradient of the responsive buffer and achieve a better buffering and suppression effect even for small pressure fluctuations; correspondingly, the adjustment component is also used to increase the resistance of the adjustable damper when the pressure impact of the power component 2 is large, so as to increase the pressure waveform gradient of the responsive buffer and prevent energy waste caused by long-term overflow.

[0052] Furthermore, the adjustable damper is provided with an adjustment knob, and the adjustment component includes a first adjustment motor connected to the adjustment knob. The first adjustment motor drives the adjustment knob to rotate forward or backward, thereby realizing the resistance adjustment of the adjustable damper.

[0053] Preferably, the nitrogen charging pressure of the accumulator 33 is adjustable, and the adjustment component is also connected to the accumulator 33 and used to adjust the accumulator 33 according to the detection result of the pressure detection component, so that the nitrogen charging pressure of the accumulator 33 can be more accurately adapted to the different working pressures of the power component 2.

[0054] Specifically, according to the accumulator's usage specifications, the nitrogen charging pressure requirement must be met during pressure fluctuations: 0.9P1≥P0≥0.25P2. Here, P1 is the lowest pressure during the fluctuation, P2 is the highest pressure during the fluctuation, and P0 is the nitrogen charging pressure of the accumulator 33. Since the working pressure range of the power component 2 will vary greatly depending on the actual working conditions, the nitrogen charging pressure of the accumulator 33 is automatically adjusted according to the different working pressures of the power component 2 to ensure that the usage specifications of the accumulator 33 are met and to achieve a better buffering effect.

[0055] Furthermore, the regulating component includes a gas filling module and a gas venting module connected to the accumulator 33. The gas filling module is used to fill the accumulator 33 with nitrogen gas to increase the nitrogen filling pressure of the accumulator 33, and the gas venting module is used to vent the accumulator 33 to decrease the nitrogen filling pressure of the accumulator 33, thereby realizing the regulation of the nitrogen filling pressure of the accumulator 33.

[0056] Furthermore, the regulating component is used to replenish nitrogen to the accumulator 33 when the working pressure of the power component 2 increases, thereby increasing the nitrogen charging pressure of the accumulator 33, preventing damage caused by over-compression of the bladder of the accumulator 33, and enhancing the buffering effect; correspondingly, the regulating component is also used to release gas from the accumulator 33 when the working pressure of the power component 2 decreases, thereby decreasing the nitrogen charging pressure of the accumulator 33, preventing damage caused by frequent venting of oil from the accumulator 33, and achieving a good buffering and suppression effect even for small pressure fluctuations.

[0057] Preferably, the spring force of the spring 314 is adjustable. The adjusting component is also connected to the spring 314 and is used to adjust the spring 314 according to the detection result of the pressure detection component, so that the spring force of the spring 314 can be more accurately adapted to the different working pressures of the power component 2. Further, the spring 314 is provided with an adjusting screw for adjusting the spring compression. The adjusting component includes a second adjusting motor connected to the adjusting screw. By driving the adjusting screw to rotate forward or backward through the second adjusting motor, the spring force of the spring 314 can be adjusted.

[0058] Specifically, the adjusting component is used to increase the elastic force of the spring 314 when the pressure impact of the power component 2 is large, so that the external control buffer valve 31 requires a larger pressure difference to push the valve core 311 open, thereby filtering out small pressure fluctuations and avoiding energy waste caused by prolonged overflow of the power component 2; correspondingly, the adjusting component is also used to decrease the elastic force of the spring 314 when the pressure impact of the power component 2 is small, so that the external control buffer valve 31 requires a smaller pressure difference to push the valve core 311 open, thereby achieving a better buffering and suppression effect for small pressure fluctuations, so as to better adapt to the buffering effect of impact, jamming or start-up conditions under light load conditions, and improve the response speed.

[0059] Furthermore, the pressure detection component is located at the first and / or second end of the power component 2. The pressure detection component includes a pressure gauge, a pressure sensor, or a pressure switch. When the pressure detection component includes a pressure gauge or a pressure sensor, it can detect the working pressure of the power component 2 in real time, with high detection accuracy and ease of use. When the pressure detection component includes a pressure switch, the pressure switch can be adjusted so that when the working pressure of the power component 2 is lower or higher than a preset value, the pressure switch automatically opens or closes. Thus, the pressure switch actively controls the adjustment component to perform its action, eliminating the need for additional complex calculation and processing modules and adjustment drive modules, resulting in a simple and efficient structure.

[0060] like Figure 4 As shown, the closed pump assembly 1 includes a closed pump 11, and a first overflow valve 12 and a second overflow valve 13 respectively arranged in parallel with the closed pump 11. The first end of the closed pump 11 is connected to the first end of the power assembly 2, and the second end of the closed pump 11 is connected to the second end of the power assembly 2.

[0061] Furthermore, the oil inlet of the first overflow valve 12 is connected to the first end of the closed-loop pump 11, and the overflow port of the first overflow valve 12 is provided with a first overflow check valve 14 that is disposed toward the second end of the closed-loop pump 11 and connected to the second end of the closed-loop pump 11; the oil inlet of the second overflow valve 13 is connected to the second end of the closed-loop pump 11, and the overflow port of the second overflow valve 13 is provided with a second overflow check valve 15 that is disposed toward the first end of the closed-loop pump 11 and connected to the first end of the closed-loop pump 11.

[0062] Since the closed-loop pump 11 is symmetrically equipped with a first overflow valve 12 and a second overflow valve 13 at both ends, when the first end of the closed-loop pump 11 is a high-pressure side oil circuit and its working pressure exceeds the set value of the first overflow valve 12, a portion of the high-pressure oil can be overflowed to the second end of the closed-loop pump 11 through the cooperation of the first overflow valve 12 and the first overflow check valve 14. This ensures that the maximum working pressure of the system does not exceed the safety limit set by the first overflow valve 12, thereby protecting the components and reducing the impact pressure of the high-pressure side oil circuit. It also replenishes oil to the low-pressure side oil circuit, achieving a buffering and suppression effect for high-pressure fluctuations. Similarly, when the second end of the closed-loop pump 11 is a high-pressure side oil circuit and its working pressure exceeds the set value of the second overflow valve 13, a portion of the high-pressure oil can also be overflowed to the first end of the closed-loop pump 11 through the cooperation of the second overflow valve 13 and the second overflow check valve 15. This achieves pressure limiting protection and buffering and suppression effects for high-pressure fluctuations in the other driving direction.

[0063] Please combine Figure 1 and Figure 4 The anti-shock hydraulic closed-loop pump control system also includes a replenishing pump assembly 4 for outputting hydraulic oil. The closed-loop pump assembly 1 further includes two replenishing check valves 16 connected to the output end of the replenishing pump assembly 4. The outlet end of one replenishing check valve 16 is connected to the first end of the closed-loop pump 11, and the outlet end of the other replenishing check valve 16 is connected to the second end of the closed-loop pump 11. Through the cooperation of the replenishing pump assembly 4 and the two replenishing check valves 16, the replenishing flow can automatically replenish the lower-pressure side of the oil circuit on both sides of the closed-loop pump 11, thereby achieving automatic replenishment of the low-pressure side oil circuit, ensuring sufficient oil in the closed-loop pump assembly 1, and preventing cavitation due to oil leakage.

[0064] Preferably, the closed-loop pump set 1 includes a flushing oil passage 17 connected to the output end of the replenishing oil pump set 4 and used for flushing the bearings and housing of the closed-loop pump 11, and a flushing damper 18 disposed between the replenishing oil pump set 4 and the flushing oil passage 17. The flushing oil passage 17 guides a portion of the oil output from the replenishing oil pump set 4 to the bearings and housing of the closed-loop pump 11 for flushing, achieving automatic cleaning and cooling of the closed-loop pump 11 and ensuring its long-term stable operation. The flushing damper 18 controls the flow rate of the flushing oil, preventing excessive flow and also preventing all the oil output from the replenishing oil pump set 4 from entering the flushing oil passage 17 and failing to effectively replenish the closed-loop oil passage between the closed-loop pump 11 and the power assembly 2.

[0065] Furthermore, the closed-loop pump unit 1 also includes a starter motor 19, which is connected to the closed-loop pump 11 and is used to drive the closed-loop pump 11 to operate, thereby driving the closed-loop pump 11.

[0066] like Figure 5 As shown, the replenishing pump group 4 includes a replenishing motor 41 and a replenishing pump 42. The replenishing motor 41 is connected to the replenishing pump 42 and is used to drive the replenishing pump 42 to rotate. The input end of the replenishing pump 42 is used to connect to the oil tank. The output end of the replenishing pump 42 is connected to the replenishing check valve 16 and the flushing oil circuit 17 respectively, and hydraulic oil is output through the replenishing pump 42.

[0067] Furthermore, the replenishing pump group 4 also includes a replenishing overflow valve 43 connected to the output end of the replenishing pump 42. The overflow port of the replenishing overflow valve 43 is used to communicate with the oil tank. The replenishing overflow valve 43 is used to control the replenishing pressure and guide excess oil back to the oil tank. That is, the pressure of the low-pressure side oil circuit of the closed pump group 1 is the same as the replenishing pressure set by the replenishing overflow valve 43, thereby realizing the pressure control of the closed pump group 1.

[0068] Please combine Figure 1 and Figure 6 The anti-impact hydraulic closed-loop pump control system also includes a flushing valve assembly 5, which includes a flushing shuttle valve 51 and a flushing overflow valve 52. The flushing shuttle valve 51 is connected in parallel with the power assembly 2 and is used to connect the low-pressure side oil circuit of the power assembly 2 to the flushing overflow valve 52. The flushing overflow valve 52 is used to connect to the oil tank and allow part of the oil in the low-pressure side oil circuit of the power assembly 2 to flow back to the oil tank through the flushing overflow valve 52, thereby removing heat and impurities in the closed loop and achieving a cooling effect. The return oil flow rate can be adjusted by adjusting the pressure of the flushing overflow valve 52 to avoid excessive oil loss in the closed loop.

[0069] Furthermore, the flushing shuttle valve 51 includes a first switching end 511 connected to the first end of the power assembly 2 and a second switching end 512 connected to the second end of the power assembly 2. The first switching end 511 is used to connect the second end of the power assembly 2 to the flushing overflow valve 52 and disconnect the first end of the power assembly 2 relative to the flushing overflow valve 52 when its pressure is greater than the pressure of the second switching end 512, thereby connecting the low-pressure side oil circuit of the power assembly 2 to the flushing overflow valve 52. Similarly, the second switching end 512 is used to connect the first end of the power assembly 2 to the flushing overflow valve 52 and disconnect the second end of the power assembly 2 relative to the flushing overflow valve 52 when its pressure is greater than the pressure of the first switching end 511.

[0070] like Figure 1 As shown, the power component 2 includes a hydraulic motor 21, which can be a gear-type, piston-type, or vane-type hydraulic motor, depending on the working environment and work requirements.

[0071] Secondly, the present invention also provides a hydraulic mechanical device (not shown in the figures, the same below), including the above-mentioned anti-impact hydraulic closed-loop pump control system. The hydraulic mechanical device can be configured as engineering machinery, mining machinery, agricultural machinery, or special-purpose machinery. Because the hydraulic mechanical device is equipped with the anti-impact hydraulic closed-loop pump control system, it can effectively reduce pressure shocks on the high-pressure side oil circuit, prevent rapid pressure drops or even cavitation in the low-pressure side oil circuit, effectively buffer and suppress continuous and repeated impacts, extend the service life of each hydraulic component, and is suitable for more complex operating conditions.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An anti-shock hydraulic closed pump control system, comprising a closed pump group (1) and a power assembly (2), the first end of the closed pump group (1) is connected with the first end of the power assembly (2), the second end of the closed pump group (1) is connected with the second end of the power assembly (2), the closed pump group (1) is used to drive the power assembly (2) to rotate and adjust the rotating speed and direction of the power assembly (2), characterized in that, The anti-impact hydraulic closed pump control system further comprises two anti-impact valve groups (3) arranged in parallel with respect to the power assembly (2), respectively, wherein the oil inlet of one anti-impact valve group (3) is connected with the first end of the power assembly (2), and the oil inlet of the other anti-impact valve group (3) is connected with the second end of the power assembly (2); The anti-impact valve group (3) comprises an externally controlled buffer valve (31), a buffer damper (32) and an accumulator (33), the spool (311) of the externally controlled buffer valve (31) is arranged in a one-way structure allowing hydraulic oil to flow only in one direction from the oil inlet to the oil outlet, the externally controlled buffer valve (31) is respectively provided with a feedback end (312) and a control end (313) on opposite sides of the spool (311), the control end (313) is provided with a spring (314) for driving the spool (311) to move towards the feedback end (312) and close, the oil inlet of the externally controlled buffer valve (31) is provided with a feedback oil path (315) connected with the feedback end (312) and a control oil path (316) connected with the control end (313), the buffer damper (32) and the accumulator (33) are sequentially arranged on the control oil path (316) in the direction towards the control end (313).

2. The shock mitigating hydraulic closed pump control system of claim 1, wherein, The anti-impact valve group (3) further comprises a backflow one-way valve (34) arranged in parallel with respect to the buffer damper (32), the inlet end of the backflow one-way valve (34) is connected with the accumulator (33), and the outlet end of the backflow one-way valve (34) is connected with the oil inlet of the externally controlled buffer valve (31).

3. The shock mitigating hydraulic closed pump control system of claim 1 or 2, wherein, The buffer damper (32) is arranged as an adjustable damper, and the anti-impact hydraulic closed pump control system further comprises a pressure detection assembly and an adjusting assembly, the pressure detection assembly is connected with the power assembly (2) and is used for detecting the working pressure of the power assembly (2) in real time, and the adjusting assembly is connected with the adjustable damper and is used for adjusting the adjustable damper according to the detection result of the pressure detection assembly.

4. The shock mitigating hydraulic closed pump control system of claim 1 or 2, wherein, The nitrogen charging pressure of the accumulator (33) is adjustable, and the anti-impact hydraulic closed pump control system further comprises a pressure detection assembly and an adjusting assembly, the pressure detection assembly is connected with the power assembly (2) and is used for detecting the working pressure of the power assembly (2) in real time, and the adjusting assembly is connected with the accumulator (33) and is used for adjusting the accumulator (33) according to the detection result of the pressure detection assembly.

5. The shock mitigating hydraulic closed pump control system of claim 1 or 2, wherein, The spring force of the spring (314) is adjustable, and the anti-impact hydraulic closed pump control system further comprises a pressure detection assembly and an adjusting assembly, the pressure detection assembly is connected with the power assembly (2) and is used for detecting the working pressure of the power assembly (2) in real time, and the adjusting assembly is connected with the spring (314) and is used for adjusting the spring (314) according to the detection result of the pressure detection assembly.

6. The shock mitigating hydraulic closed pump control system of claim 1, wherein, The closed pump group (1) comprises a closed pump (11), and a first overflow valve (12) and a second overflow valve (13) arranged in parallel with respect to the closed pump (11) respectively, a first end of the closed pump (11) is connected with a first end of the power assembly (2), and a second end of the closed pump (11) is connected with a second end of the power assembly (2); An oil inlet of the first overflow valve (12) is connected with the first end of the closed pump (11), and an overflow port of the first overflow valve (12) is provided with a first overflow check valve (14) arranged along the second end of the closed pump (11) and connected with the second end of the closed pump (11); An oil inlet of the second overflow valve (13) is connected with the second end of the closed pump (11), and an overflow port of the second overflow valve (13) is provided with a second overflow check valve (15) arranged along the first end of the closed pump (11) and connected with the first end of the closed pump (11).

7. The shock mitigating hydraulic closed pump control system of claim 6, wherein, The anti-impact hydraulic closed pump control system further comprises a supplemental oil pump group (4) for outputting hydraulic oil, the closed pump group (1) further comprises two supplemental oil check valves (16) connected with output ends of the supplemental oil pump group (4) respectively, an outlet end of one of the supplemental oil check valves (16) is connected with the first end of the closed pump (11), and an outlet end of the other supplemental oil check valve (16) is connected with the second end of the closed pump (11).

8. The closed center hydraulic pump control system of claim 7, wherein, The closed pump group (1) comprises a flushing oil path (17) connected with the output ends of the supplemental oil pump group (4) and used for flushing bearings and housings of the closed pump (11), and a flushing damper (18) arranged between the supplemental oil pump group (4) and the flushing oil path (17).

9. The shock mitigating hydraulic closed pump control system of claim 1, wherein, The anti-impact hydraulic closed pump control system further comprises a flushing valve group (5), the flushing valve group (5) comprises a flushing shuttle valve (51) and a flushing overflow valve (52), the flushing shuttle valve (51) is arranged in parallel with the power assembly (2) and is used for conducting a low-pressure side oil path of the power assembly (2) with the flushing overflow valve (52), and the flushing overflow valve (52) is used for being connected with an oil tank and making part of oil in the low-pressure side oil path of the power assembly (2) flow back to the oil tank through the flushing overflow valve (52).

10. A hydraulic machine characterized by The anti-impact hydraulic closed pump control system comprises the anti-impact hydraulic closed pump control system according to any one of claims 1 to 9.

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