Overflow prevention systems, operating machinery, and overflow prevention methods

Abstract

This invention relates to the field of work machinery technology, and discloses an overflow prevention system, work machinery, and overflow prevention method, including: an actuator cylinder, a power pump, an overflow valve, a position sensor, and a control module. The actuator cylinder is adapted to extend and retract to perform work actions. The output end of the power pump is connected to the actuator cylinder, and the inlet end of the overflow valve is connected to the output end of the power pump. The position sensor is adapted to detect the extension and retraction position of the actuator cylinder. The control module is communicatively connected to the power pump and the position sensor. When the control module is activated, it controls the power pump to gradually reduce its rotational speed at a preset acceleration to reduce the output flow rate until the actuator cylinder extends and retracts to its limit position. At this point, the output flow rate of the power pump is reduced to the preset flow rate. Under this preset flow rate condition, the pressure at the output end of the power pump is less than the opening pressure of the overflow valve. This ensures that the overflow valve does not overflow during this process, avoiding valve jamming and overflow losses.

Description

Technical Field

[0001] This invention relates to the field of operating machinery technology, specifically to overflow prevention systems, operating machinery, and overflow prevention methods. Background Technology

[0002] Operating machinery is widely used in various fields, such as machine tools, cranes, excavators, and loaders. Hydraulic systems are widely applied in these machines. A hydraulic (pneumatic) system includes a power pump, hydraulic valves (air valves), and actuators. The power pump is connected to the actuators via hydraulic valves, providing power to drive the actuators to extend and retract, thus performing the operating action. To prevent excessive pressure, a relief valve is often installed in the hydraulic system. When the pressure in the relief valve exceeds the overflow pressure, the valve automatically opens, allowing excess liquid or gas to flow out from the overflow port, keeping the pressure within the hydraulic (pneumatic) system below the overflow pressure to maintain system stability.

[0003] However, the overflow valve is prone to jamming during the overflow process, and once jamming occurs, the entire machine will not work. Moreover, the overflow valve has overflow losses during operation, that is, some energy is lost in the form of heat during the overflow process and cannot be effectively utilized by the system. Summary of the Invention

[0004] In view of this, the present invention provides an overflow prevention system, a working machine, and an overflow prevention method to solve the problems of high probability of jamming and large overflow loss when the overflow valve of the working machine overflows.

[0005] In a first aspect, the present invention provides an overflow prevention system, comprising:

[0006] The actuator is suitable for extending and retracting to perform operational actions.

[0007] A power pump, the output end of which is connected to the actuator cylinder, is adapted to drive the actuator cylinder to extend and retract;

[0008] The overflow valve has its inlet end connected to the output end of the power pump;

[0009] A position sensor, adapted to detect the extension and retraction position of the actuator cylinder;

[0010] The control module is communicatively connected to the power pump and the position sensor. The control module is adapted to determine when the actuator cylinder extends or retracts to a preset position, and control the power pump to gradually reduce its rotation speed with a preset acceleration to reduce the output flow rate until the actuator cylinder extends or retracts to its limit position, at which point the output flow rate of the power pump is reduced to a preset flow rate; wherein, under the condition of the preset flow rate, the pressure at the output end of the power pump is less than the opening pressure of the overflow valve.

[0011] Beneficial Effects: As the actuator cylinder extends and retracts from its initial position to its limit position, the pressure at the power pump output gradually increases. When the position sensor detects that the actuator cylinder has extended or retracted to the preset position, it sends a signal to the control module, which then confirms that the actuator cylinder has reached the preset position. The control module immediately controls the power pump to gradually reduce its speed and output flow by a preset acceleration. Thus, during the extension and retraction of the actuator cylinder from the preset position to the limit position, the power pump's output flow gradually decreases, while the pressure at the power pump's output increases with a small trend. This ensures that when the actuator cylinder reaches its limit position, the power pump's output flow decreases to a preset flow rate, which is only used to balance minor flows such as internal leakage. When the power pump outputs the preset flow rate, the pressure at the power pump's output increases to a value lower than the relief valve's opening pressure, maintaining the actuator cylinder at its limit position. This ensures that the relief valve does not overflow during this process, avoiding valve jamming and overflow losses.

[0012] In one alternative implementation, it further includes:

[0013] A pressure sensor, communicatively connected to the control module, is adapted to detect the pressure at the inlet of the relief valve, wherein:

[0014] The control module is adapted to determine that, under the condition that the pressure at the inlet end of the overflow valve is less than the opening pressure of the overflow valve and the actuator cylinder is extended to a preset position, control the power pump to gradually reduce the speed of the power pump with the preset acceleration to reduce the output flow rate, until the actuator cylinder is extended to the limit position, and the output flow rate of the power pump is reduced to the preset flow rate;

[0015] The control module is also adapted to determine, under the condition that the pressure at the inlet of the overflow valve is not less than the opening pressure of the overflow valve, to control the power pump to reduce its speed to reduce the output flow, so that the pressure at the inlet of the overflow valve is less than the opening pressure of the overflow valve.

[0016] Beneficial effects: When the control module determines that the pressure at the inlet of the relief valve is not less than the opening pressure of the relief valve, the control module controls the power pump to reduce the speed and output flow, so that the pressure at the inlet of the relief valve is reduced to less than the opening pressure of the relief valve, thereby ending the relief valve overflow as soon as possible, reducing the overflow time of the relief valve, and avoiding the increased probability of jamming and the increase of overflow loss caused by the long overflow time of the relief valve.

[0017] In one alternative implementation, it further includes:

[0018] The pressure relief flow path is connected to the output end of the power pump. The pressure relief flow path is equipped with a solenoid valve. The control module is communicatively connected to the solenoid valve. The control module is adapted to control the power pump to reduce its speed to reduce the output flow when the pressure at the inlet end of the overflow valve is not less than the opening pressure of the overflow valve. When it is determined that the pressure at the inlet end of the overflow valve remains unchanged or continues to increase, the control module controls the power pump to depressurize.

[0019] Beneficial effects: Under the condition that the pressure at the inlet of the relief valve is not less than the opening pressure of the relief valve and the output flow of the power pump is reduced, the control module controls the solenoid valve to open when the pressure at the inlet of the relief valve remains unchanged or continues to increase. This causes part of the flow output by the power pump to be discharged through the pressure relief path, reducing the pressure at the output of the power pump to less than the opening pressure of the relief valve, ending the relief valve overflow as soon as possible, reducing the overflow time of the relief valve, and avoiding the increased probability of jamming and increased overflow loss caused by a long overflow time.

[0020] In one alternative implementation, it further includes:

[0021] A one-way valve is provided, through which the output end of the power pump is connected to the actuator cylinder. The one-way valve is adapted to unidirectionally open when the power pump outputs flow to the actuator cylinder.

[0022] Beneficial effect: Prevents oil from flowing back into the hydraulic pump.

[0023] In one optional embodiment, multiple actuators are provided and each is connected to the power pump, and multiple position sensors are provided and each is communicatively connected to the control module. Each position sensor is adapted to detect the extension and retraction position of one actuator.

[0024] Beneficial effects: For different actuators, the corresponding position sensor detects their position, enabling the control module to control the output flow of the power pump for different actuators, thereby preventing the overflow valve from overflowing.

[0025] Secondly, the present invention also provides a working machine equipped with a hydraulic system, the hydraulic system including any of the overflow prevention systems described above.

[0026] Beneficial effects: The beneficial effects of this machine are the same as those of the overflow prevention system, so they will not be elaborated further.

[0027] Thirdly, the present invention also provides an overflow prevention method, wherein a power pump is connected to an actuator cylinder, the power pump being adapted to drive the actuator cylinder to extend and retract to perform an operation, and an overflow valve is connected to the power pump, the overflow prevention method comprising:

[0028] When the actuator cylinder extends or retracts to a preset position, the power pump is controlled to gradually reduce its rotational speed with a preset acceleration to reduce the output flow rate until the actuator cylinder extends or retracts to its limit position, at which point the output flow rate of the power pump is reduced to a preset flow rate; wherein, under the preset flow rate condition, the pressure at the output end of the power pump is less than the opening pressure of the overflow valve.

[0029] Beneficial effects: When the actuator cylinder extends or retracts to the preset position, the control power pump gradually reduces its speed and output flow by a preset acceleration. Thus, as the actuator cylinder extends or retracts from the preset position to its limit position, the output flow of the power pump gradually decreases, while the pressure at the output end of the power pump increases with a small trend. This ensures that when the actuator cylinder reaches its limit position, the output flow of the power pump drops to the preset flow rate, which is only used to balance minor flow such as internal leakage. At the preset flow rate output from the power pump's output end, the pressure at the output end increases to a value lower than the opening pressure of the relief valve, maintaining the actuator cylinder in its limit position. This ensures that the relief valve does not overflow during this process, avoiding valve jamming and overflow losses.

[0030] In one alternative implementation, it includes:

[0031] When the pressure at the inlet of the overflow valve is less than the opening pressure of the overflow valve, and the actuator cylinder is extended to a preset position, the power pump is controlled to gradually reduce its speed with the preset acceleration to reduce the output flow rate until the actuator cylinder is extended to its limit position, at which point the output flow rate of the power pump is reduced to the preset flow rate.

[0032] Under the condition that the pressure at the inlet of the overflow valve is not less than the opening pressure of the overflow valve, the speed of the power pump is controlled to decrease to reduce the output flow, so that the pressure at the inlet of the overflow valve is less than the overflow pressure.

[0033] Beneficial effects: Under the condition that the pressure at the inlet of the relief valve is not less than the opening pressure of the relief valve and the output flow of the power pump is controlled to decrease, if the pressure at the inlet of the relief valve remains unchanged or continues to increase, the solenoid valve is controlled to open. This allows part of the flow output by the power pump to be discharged through the pressure relief path, reducing the pressure at the output of the power pump to less than the opening pressure of the relief valve, ending the relief valve overflow as soon as possible, reducing the overflow time of the relief valve, and avoiding the increased probability of jamming and increased overflow loss caused by a long overflow time.

[0034] In one optional implementation, after determining that the pressure at the inlet of the relief valve is not less than the opening pressure of the relief valve, and controlling the power pump to reduce its speed to decrease the output flow, the method further includes:

[0035] When the pressure at the inlet of the relief valve remains constant or continues to increase, the power pump is controlled to depressurize.

[0036] Beneficial effects: Under the condition that the pressure at the inlet of the relief valve is not less than the opening pressure of the relief valve and the output flow of the power pump is reduced, if the pressure at the inlet of the relief valve remains unchanged or continues to increase, the pressure at the output of the power pump will be released to end the overflow of the relief valve as soon as possible, thereby reducing the overflow time of the relief valve and avoiding the increased probability of jamming and the increase in overflow loss caused by the long overflow time of the relief valve.

[0037] In one alternative implementation, it further includes:

[0038] When the actuator cylinder extends from its initial position to its limit position, and when the actuator cylinder extends to the working position, the power pump is controlled to reduce its speed to reduce the output flow, so that the pressure of the relief valve is less than the relief pressure. The extension position of the actuator cylinder when the pressure at the inlet end of the relief valve is greater than the opening pressure of the relief valve is the working position.

[0039] Beneficial effects: When the actuator cylinder extends or retracts to the working position, the power pump is immediately controlled to reduce its speed and output flow, which slows down the increase in pressure at the power pump output end. This prevents the pressure at the power pump output end from increasing to exceed the opening pressure of the relief valve, or causes the pressure at the power pump output end to briefly exceed the opening pressure of the relief valve before dropping below it. This allows the relief valve to stop overflowing more quickly, reducing the overflow time and avoiding increased jamming probability and overflow loss caused by prolonged overflow time. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of an overflow prevention system according to an embodiment of the present invention;

[0042] Figure 2 This is a schematic flowchart of an overflow prevention method according to an embodiment of the present invention;

[0043] Figure 3 This is a diagram showing the relationship between the pressure P at the inlet of the overflow valve and the extension / retraction stroke L of the actuator cylinder in an anti-overflow method according to an embodiment of the present invention.

[0044] Figure 4 This is a graph showing the relationship between the output flow rate Q of the power pump and the pressure P at the inlet of the overflow valve in an overflow prevention method according to an embodiment of the present invention.

[0045] Figure 5 This is a schematic flowchart of another overflow prevention method according to an embodiment of the present invention;

[0046] Figure 6 This is a diagram showing the relationship between the pressure P at the inlet of the overflow valve and the extension / retraction stroke L of the actuator cylinder in another overflow prevention method according to an embodiment of the present invention.

[0047] Explanation of reference numerals in the attached figures:

[0048] 1. Power pump; 2. Actuator cylinder; 3. Relief valve; 4. Position sensor; 5. Pressure sensor; 6. Solenoid valve; 7. Check valve; 8. Directional control valve; 9. Oil tank. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] The following is combined with Figures 1 to 6 The following describes embodiments of the present invention.

[0051] According to embodiments of the present invention, in one aspect, such as Figure 1 As shown, an anti-overflow system is provided for use in a loader. This anti-overflow system includes: an actuator cylinder 2, a power pump 1, an overflow valve 3, a position sensor 4, and a control module. The actuator cylinder 2 is a hydraulic cylinder, and the power pump 1 is a hydraulic pump. The output of the power pump 1 is connected to a solenoid directional valve 8 via a pipeline, and then to the inlet of the actuator cylinder 2. The outlet of the actuator cylinder 2 is connected to the solenoid directional valve 8 via a pipeline, and then to the oil tank 9. Thus, the power pump 1 outputs oil, which drives the actuator cylinder 2 to its initial and extreme positions L via the solenoid directional valve 8. max The device extends and retracts to perform operational actions, such as lifting and tipping. The inlet of the overflow valve 3 is connected to the output of the power pump 1 via a pipeline, and the outlet of the overflow valve 3 is connected to the oil tank 9 via a pipeline. The pressure at the output of the power pump 1 is the same as the pressure at the inlet of the overflow valve 3. When the pressure at the output of the power pump 1 is greater than the opening pressure of the overflow valve 3, the overflow valve 3 opens and overflows the excess flow from the output of the power pump 1 to the oil tank 9, thus controlling the pressure at the output of the power pump 1 to remain less than or equal to the opening pressure of the overflow valve 3.

[0052] When cylinder 2 extends and retracts to perform its working action, position sensor 4 detects the extension and retraction position of cylinder 2 in real time, that is, where cylinder 2 extends and retracts to at a certain moment. The control module is communicatively connected to power pump 1 and position sensor 4 respectively. The control module can control the speed of power pump 1 to reduce the output flow. After detecting the extension and retraction position of cylinder 2, position sensor 4 can send a signal containing the position information of cylinder 2 to the control module.

[0053] like Figure 2 , Figure 3 and Figure 4 As shown, in the initial position and the extreme position L max A preset position L is set between them. b When actuator 2 is in its initial position, its extension / retraction is 0, and the output pressure of power pump 1 is 0. Power pump 1 then starts operating at Q... e When outputting flow, actuator 2 starts moving from the initial position to the extreme position L. max As the cylinder extends and retracts, the pressure at the output end of the power pump 1 gradually increases. Position sensor 4 monitors the extension and retraction position of actuator 2 in real time. When position sensor 4 detects that actuator 2 has extended or retracted to the preset position L... b At that time, a signal is sent to the control module, thereby the control module determines that the actuator 2 extends or retracts to the preset position L. b The control module immediately sends a control signal to power pump 1 to control power pump 1 to gradually reduce its speed and thus reduce the output flow by a preset acceleration. This is done as actuator 2 moves from the preset position to its limit position L. max During the extension and retraction process, the output flow rate Q of power pump 1 gradually decreases, while the pressure P at the output end of power pump 1 increases with a small trend. This causes the actuator cylinder 2 to extend or retract to its limit position L. max At that time, the pressure P at the output end of power pump 1 increases to P c The output flow rate of power pump 1 decreases to the preset flow rate Q0. As power pump 1 continues to output flow, the pressure P at the output end of power pump 1 increases to the working pressure P. d After that, it will not rise further. This preset flow rate Q0 is only used to balance the small flow caused by internal leakage, etc. The pressure P at the output end of the power pump 1 is maintained at the working pressure P. d It stopped rising. Due to work pressure P d The opening pressure P of the relief valve 3 is less than max This ensures that the overflow valve 3 will not overflow during this process, thus preventing the overflow valve 3 from getting stuck and causing overflow loss.

[0054] Among them, the preset position L bThe preset acceleration can be calculated based on actual conditions and is mainly related to the overflow pressure threshold of the overflow valve 3. The overflow pressure threshold is related to the operating conditions of the machine and the selection and configuration of the actuator 2, with the basic principle of not affecting the operator's operating experience. The preset acceleration can be a constant value or a variable value, set according to actual needs.

[0055] Preset position L b Multiple preset accelerations can be set. For example, the overflow pressure threshold of the overflow valve 3 is a fixed value, which is necessarily greater than the maximum working pressure actually required by the machine. However, the actual working pressure required by the machine varies under different operating conditions, such as heavy load and light load. Therefore, when the actuator cylinder 2 extends to its limit position, there is a difference between the overflow pressure threshold and the actual working pressure value. Within the difference range, although no overflow will occur, unnecessary energy loss and waste will result. At this time, different preset positions and preset accelerations can be set according to different differences under different operating conditions or loads to further reduce energy loss while controlling overflow. Specifically, the larger the difference, the higher the preset position L. b It can be set to the extreme position L further away from the actuator cylinder. max That is, the longer the extension and retraction stroke of the actuator cylinder is set, the higher the pressure of the actuator cylinder will reach the limit position L. max The working pressure P can be gradually increased to the actual work pressure required. d Alternatively, the preset flow acceleration can be set to a higher value, that is, a faster reduction in flow rate so that the cylinder pressure can be slowly increased to the actual working pressure P required for operation. d .

[0056] One of the power pumps can be a fixed displacement pump, which makes it easier to control the output flow rate of the power pump.

[0057] In some embodiments, the overflow prevention system further includes a pressure sensor 5. The pressure sensor 5 is disposed on a pipeline connected to the inlet of the overflow valve 3 to detect the pressure at the inlet of the overflow valve 3. The pressure sensor 5 is communicatively connected to the control module, and after detecting the pressure at the inlet of the overflow valve 3, it sends a signal containing the pressure information of the inlet of the overflow valve 3 to the control module. The pressure at the inlet of the overflow valve 3 is the same as the pressure output of the pressure pump.

[0058] like Figure 5 and Figure 6 As shown, when the actuator cylinder 2 moves from the initial position to the extreme position L... max During the extension and retraction process, pressure sensor 5 monitors the pressure at the inlet of overflow valve 3 in real time.

[0059] When actuator 2 is unloaded or under constant load during extension and retraction, before reaching the limit position L... max Previously, the pressure at the inlet of relief valve 3 was less than the opening pressure P of relief valve 3.max The control module can determine, based on the information detected by pressure sensor 5, that the pressure at the inlet of relief valve 3 is less than the opening pressure P of relief valve 3. max Under these conditions, when position sensor 4 detects that actuator 2 has extended or retracted to the preset position L... b At that time, a signal is sent to the control module, thereby the control module determines that the actuator 2 extends or retracts to the preset position L. b Then, the control module immediately sends a control signal to power pump 1 to control power pump 1 to gradually reduce its speed and output flow by a preset acceleration. Thus, as actuator 2 moves from the preset position to its limit position L... max During the extension and retraction process, the output flow rate Q of power pump 1 gradually decreases, while the pressure P at the output end of power pump 1 increases with a small trend. This causes the actuator cylinder 2 to extend or retract to its limit position L. max At that time, the pressure P at the output end of power pump 1 increases to P c The output flow rate of power pump 1 decreases to the preset flow rate Q0. As power pump 1 continues to output flow, the pressure P at the output end of power pump 1 increases to the working pressure P. d After that, it will not rise further. This preset flow rate Q0 is only used to balance the small flow caused by internal leakage, etc. The pressure P at the output end of the power pump 1 is maintained at the working pressure P. d It stopped rising. Due to work pressure P d The opening pressure P of the relief valve 3 is less than max This ensures that the overflow valve 3 will not overflow during this process, thus preventing the overflow valve 3 from getting stuck and causing overflow loss.

[0060] When the actuator 2 is suddenly loaded at L1, the continuous output flow of the power pump 1 causes the pressure P at the output of the power pump 1 to suddenly increase to exceed the opening pressure P of the relief valve 3. max The control module can determine, based on the information detected by pressure sensor 5, that the pressure at the inlet of relief valve 3 must not be less than the opening pressure P of relief valve 3. max Under these conditions, the control module controls the power pump 1 to reduce its speed and output flow, so that the pressure at the inlet of the relief valve 3 decreases to below the opening pressure of the relief valve 3, thereby ending the overflow of the relief valve 3 as soon as possible, reducing the overflow time of the relief valve 3, and avoiding the increased probability of jamming and overflow loss caused by a long overflow time of the relief valve 3. This continues until the actuator 2 extends to its limit position L. max At this time, the output flow rate of power pump 1 is reduced to a small flow rate used only to balance internal leakage, etc., and the pressure at the output end of power pump 1 is reduced to maintain actuator 2 at its limit position L. max Required working pressure P d It will not rise further. This ensures that the relief valve 3 will not overflow during this process, preventing the relief valve 3 from getting stuck and causing overflow losses.

[0061] It is worth noting that if L1 is located in L b Previously, even if the power pump 1 was controlled to reduce its speed and thus decrease its output flow, so that the pressure at the inlet of the relief valve 3 was reduced to less than the opening pressure of the relief valve 3, the control module would no longer determine whether the actuator cylinder 2 would extend or retract to the preset position L. b .

[0062] In a further embodiment, such as Figure 1 As shown, the overflow prevention system also includes a pressure relief path, one end of which is connected to the output end of the power pump 1, and the other end of which is connected to the oil tank 9. A solenoid valve 6 is installed in the pressure relief path, and the control module is communicatively connected to the solenoid valve 6. Thus, the control module can control the solenoid valve 6 to open or close.

[0063] like Figure 5 As shown, the control module determines that the inlet pressure P of the relief valve 3 is not less than the opening pressure P of the relief valve 3. max Under the condition that the output flow rate Q of the power pump 1 decreases, the control module determines, based on the signal detected in real time by the pressure sensor 5, whether the pressure at the inlet of the relief valve 3 remains unchanged or continues to increase. At this point, the control module opens the solenoid valve 6. This allows a portion of the flow rate output by the power pump 1 to be released to the oil tank 9 through the pressure relief path, thereby reducing the pressure at the output of the power pump 1 to below the opening pressure of the relief valve 3 until the working pressure P is reached. d End the overflow of relief valve 3 as soon as possible to reduce the overflow time of relief valve 3 and avoid the increased probability of jamming and the increase of overflow loss caused by the long overflow time of relief valve 3.

[0064] The control module can also determine whether the pressure at the inlet of the relief valve 3 is greater than the working pressure P based on the signal detected and emitted in real time by the pressure sensor 5. d At this time, the control solenoid valve 6 opens. This causes a portion of the flow output from the power pump 1 to be released to the oil tank 9 through the pressure relief path, thereby reducing the pressure at the output of the power pump 1 to below the opening pressure of the relief valve 3, until it is reduced to the working pressure P. d .

[0065] When the control module controls the solenoid valve 6 to open, it should ensure that the user does not actively increase or maintain the speed of the power pump 1 to increase or maintain the output flow. That is, if the user actively reduces the speed of the power pump 1, and the power pump 1 cannot reduce the speed to reduce the output flow, the pressure at the inlet of the relief valve 3 will continue to increase, and only then will the control module control the solenoid valve 6 to open.

[0066] In some embodiments, the anti-overflow system further includes a one-way valve 7, wherein the output end of the power pump 1 is connected to the actuator cylinder 2 via the one-way valve 7, allowing unidirectional flow when the power pump 1 outputs flow to the actuator cylinder 2. This prevents oil from flowing back into the hydraulic pump.

[0067] In some embodiments, multiple actuators 2 are provided, such as two lifting cylinders and one reversing cylinder in a loader. Each actuator 2 is connected to the power pump 1 via a reversing valve 8. The reversing valve 8 allows the power pump 1 to drive each actuator 2 to extend and retract to perform the operation. Correspondingly, multiple position sensors 4 are provided and communicate with the control module. Each position sensor 4 corresponds to one actuator 2, and each position sensor 4 detects the extension and retraction position of its corresponding actuator 2. This arrangement allows the control module to control the output flow of the power pump 1 for different actuators 2, thus preventing overflow from the relief valve 3.

[0068] According to an embodiment of the present invention, another aspect provides a working machine equipped with a hydraulic system, which includes any of the overflow prevention systems described above. The beneficial effects of this working machine are consistent with those of the overflow prevention system, and therefore will not be repeated.

[0069] According to an embodiment of the present invention, in another aspect, such as Figures 2-4 As shown, an overflow prevention method is also provided, wherein the output end of the power pump 1 is connected to the actuator 2, the power pump 1 is adapted to drive the actuator 2 to extend and retract to perform the operation, and the inlet end of the overflow valve 3 is connected to the output end of the power pump 1.

[0070] Cylinder 2 in initial position and extreme position L max During the extension and retraction of the actuator cylinder 2 and the execution of the operation, the extension and retraction position of the actuator cylinder 2 is determined in real time. This is done at both the initial position and the extreme position L. max A preset position L is set between them. b When actuator 2 is in its initial position, its extension / retraction is 0, and the output pressure of power pump 1 is 0. Power pump 1 then starts operating at Q... e When outputting flow, actuator 2 starts moving from the initial position to the extreme position L. max As the pump extends and retracts, the pressure at the output end of power pump 1 gradually increases.

[0071] When it is determined that the actuator 2 has extended or retracted to the preset position L b At this time, the control power pump 1 gradually reduces its speed with a preset acceleration, thereby reducing the output flow. Thus, as the actuator 2 moves from the preset position to its extreme position L... max During the extension and retraction process, the output flow rate Q of power pump 1 gradually decreases, while the pressure P at the output end of power pump 1 increases with a small trend. This causes the actuator cylinder 2 to extend or retract to its limit position L. max At that time, the pressure P at the output end of power pump 1 increases to P c The output flow rate of power pump 1 decreases to the preset flow rate Q0. As power pump 1 continues to output flow, the pressure P at the output end of power pump 1 increases to the working pressure P. dAfter that, it will not rise further. This preset flow rate Q0 is only used to balance the small flow caused by internal leakage, etc. The pressure P at the output end of the power pump 1 is maintained at the working pressure P. d It stopped rising. Due to work pressure P d The opening pressure P of the relief valve 3 is less than max This ensures that the overflow valve 3 will not overflow during this process, thus preventing the overflow valve 3 from getting stuck and causing overflow loss.

[0072] In a further embodiment, the anti-overflow method further includes: when the actuator 2 moves from the initial position to the extreme position L max During the expansion and contraction process, ensure that the pressure at the inlet of relief valve 3 is less than the opening pressure P of relief valve 3. max Or not less than the opening pressure P of relief valve 3 max .

[0073] When actuator 2 is unloaded or under constant load during extension and retraction, before reaching the limit position L... max Previously, the pressure at the inlet of relief valve 3 was less than the opening pressure P of relief valve 3. max It is determined that the pressure at the inlet of relief valve 3 is less than the opening pressure P of relief valve 3. max Under the condition of determining the extension and retraction of cylinder 2 to the preset position L b At this time, the control power pump 1 gradually reduces its speed with a preset acceleration, thereby reducing the output flow. Thus, as the actuator 2 moves from the preset position to its extreme position L... max During the extension and retraction process, the output flow rate Q of power pump 1 gradually decreases, while the pressure P at the output end of power pump 1 increases with a small trend. This causes the actuator cylinder 2 to extend or retract to its limit position L. max At that time, the pressure P at the output end of power pump 1 increases to P c The output flow rate of power pump 1 decreases to the preset flow rate Q0. As power pump 1 continues to output flow, the pressure P at the output end of power pump 1 increases to the working pressure P. d After that, it will not rise further. This preset flow rate Q0 is only used to balance the small flow caused by internal leakage, etc. The pressure P at the output end of the power pump 1 is maintained at the working pressure P. d It stopped rising. Due to work pressure P d The opening pressure P of the relief valve 3 is less than max This ensures that the overflow valve 3 will not overflow during this process, thus preventing the overflow valve 3 from getting stuck and causing overflow loss.

[0074] When the actuator 2 is suddenly loaded at L1, the continuous output flow of the power pump 1 causes the pressure P at the output of the power pump 1 to suddenly increase to exceed the opening pressure P of the relief valve 3. max Ensure that the pressure at the inlet of relief valve 3 is not less than the opening pressure P of relief valve 3. maxUnder these conditions, the speed of the power pump 1 is reduced, thereby decreasing the output flow rate. This reduces the pressure at the inlet of the relief valve 3 to below its opening pressure, thus ending the overflow of the relief valve 3 as quickly as possible, reducing its overflow time, and preventing increased jamming probability and overflow losses due to prolonged overflow. This continues until the actuator 2 extends to its limit position L. max At this time, the output flow rate of power pump 1 is reduced to a small flow rate used only to balance internal leakage, etc., and the pressure at the output end of power pump 1 is reduced to maintain actuator 2 at its limit position L. max Required working pressure P d It will not rise further. This ensures that the relief valve 3 will not overflow during this process, preventing the relief valve 3 from getting stuck and causing overflow losses.

[0075] It is worth noting that if L1 is located in L b Previously, even if the speed of the power pump 1 was reduced to decrease the output flow, so that the pressure at the inlet of the relief valve 3 was reduced to less than the opening pressure of the relief valve 3, it was no longer certain that the actuator 2 would extend or retract to the preset position L. b .

[0076] In a further embodiment, such as Figure 5 As shown, when the pressure P at the inlet of the relief valve 3 is not less than the opening pressure P of the relief valve 3, max Under the condition that the output flow rate Q of the power pump 1 decreases, if the pressure at the inlet of the relief valve 3 remains unchanged or continues to increase, the power pump 1 is depressurized, thereby reducing the pressure at the output of the power pump 1 to less than the opening pressure of the relief valve 3 until the working pressure P is reached. d End the overflow of relief valve 3 as soon as possible to reduce the overflow time of relief valve 3 and avoid the increased probability of jamming and the increase of overflow loss caused by the long overflow time of relief valve 3.

[0077] It can also be determined that the pressure at the inlet of the relief valve 3 is greater than the working pressure P. d At this time, the control solenoid valve 6 opens. This causes a portion of the flow output from the power pump 1 to be released to the oil tank 9 through the pressure relief path, thereby reducing the pressure at the output of the power pump 1 to below the opening pressure of the relief valve 3, and eventually reducing it to the working pressure P. d .

[0078] In some embodiments, the anti-overflow method further includes: determining that the actuator 2 extends from the initial position to the limit position, and determining that when the actuator 2 extends to the working position, controlling the power pump 1 to reduce the output flow so that the pressure of the overflow valve 3 is less than the overflow pressure, thereby ending the overflow of the overflow valve 3 more quickly, reducing the overflow time of the overflow valve 3, and avoiding the overflow time of the overflow valve 3 from being too long, which would lead to an increased probability of jamming and an increased overflow loss.

[0079] Specifically, based on AI large-scale model statistics, it is determined that under a certain working condition, the actuator 2 extends to a certain position and begins to bear the load. The extension / retraction position of the actuator 2 at this point is the working position under that working condition. When the actuator 2 begins to bear the load, the pressure at the output end of the power pump 1 will increase sharply. In the actual working condition, when the actuator 2 extends from its initial position to its limit position, and it is determined that the actuator 2 has extended to the working position, the power pump 1 is immediately controlled to reduce its speed and output flow, thus slowing down the rate of pressure increase at the output end of the power pump 1. This prevents the pressure at the output end of the power pump 1 from increasing to exceed the opening pressure of the relief valve 3, or causes the pressure at the output end of the power pump 1 to briefly exceed the opening pressure of the relief valve 3 before decreasing to below the opening pressure of the relief valve 3. This allows the relief valve 3 to terminate its overflow more quickly, reducing the overflow time of the relief valve 3 and avoiding increased jamming probability and overflow loss due to prolonged overflow time.

[0080] It is worth noting that the corresponding work positions under various working conditions can be statistically analyzed, and control can be carried out based on the corresponding work position under a certain working condition.

[0081] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by this application.

Claims

1. An overflow prevention system, characterized in that, include: The actuator (2) is suitable for telescopic operation. A power pump (1) is connected to the actuator (2) at its output end. The power pump (1) is adapted to drive the actuator (2) to extend and retract. The overflow valve (3) has its inlet end connected to the output end of the power pump (1); A position sensor (4) is adapted to detect the extension and retraction position of the actuator (2); Pressure sensor (5) is adapted to detect the pressure at the inlet of the overflow valve (3); The control module is communicatively connected to the power pump (1), the position sensor (4), and the pressure sensor (5), respectively, wherein: The control module is adapted to determine that, under the condition that the pressure at the inlet end of the overflow valve (3) is less than the opening pressure of the overflow valve (3) and the actuator (2) is extended to a preset position, the power pump (1) is controlled to gradually reduce the speed of the power pump (1) with a preset acceleration to reduce the output flow until the actuator (2) is extended to the limit position, and the output flow of the power pump (1) is reduced to a preset flow. Under the condition of the preset flow, the pressure at the output end of the power pump (1) is less than the opening pressure of the overflow valve (3). The control module is also adapted to determine, under the condition that the pressure at the inlet of the overflow valve (3) is not less than the opening pressure of the overflow valve, to control the power pump (1) to reduce the speed to reduce the output flow, so that the pressure at the inlet of the overflow valve is less than the opening pressure of the overflow valve.

2. The overflow prevention system according to claim 1, characterized in that, Also includes: The pressure relief flow path is connected to the output end of the power pump (1). The pressure relief flow path is equipped with a solenoid valve (6). The control module is communicatively connected to the solenoid valve (6). The control module is adapted to control the power pump (1) to reduce its speed to reduce the output flow under the condition that the pressure at the inlet end of the overflow valve (3) is not less than the opening pressure of the overflow valve (3). When it is determined that the pressure at the inlet end of the overflow valve (3) remains unchanged or continues to increase, the control module controls the power pump (1) to depressurize.

3. The overflow prevention system according to claim 2, characterized in that, Also includes: A one-way valve (7) is provided, through which the output end of the power pump (1) is connected to the actuator (2), and the one-way valve (7) is adapted to unidirectionally conduct when the power pump (1) outputs flow to the actuator (2).

4. The overflow prevention system according to claim 1, characterized in that, Multiple actuators (2) are provided and are respectively connected to the power pump (1). Multiple position sensors (4) are provided and are respectively connected to the control module. Each position sensor (4) is adapted to detect the extension and retraction position of one actuator (2).

5. A type of operating machinery, characterized in that, A hydraulic system is provided, the hydraulic system including the anti-overflow system as described in any one of claims 1-4.

6. An overflow prevention method, characterized in that, A power pump (1) is connected to an actuator (2), the power pump (1) being adapted to drive the actuator (2) to extend and retract to perform an operation. An overflow valve (3) is connected to the power pump (1), and the overflow prevention method includes: Under the condition that the pressure at the inlet end of the overflow valve (3) is less than the opening pressure of the overflow valve (3) and the actuator (2) is extended to a preset position, the power pump (1) is controlled to gradually reduce its speed with a preset acceleration to reduce the output flow until the actuator (2) is extended to the limit position, at which point the output flow of the power pump (1) is reduced to a preset flow. Under the condition of the preset flow, the pressure at the output end of the power pump (1) is less than the opening pressure of the overflow valve (3). Under the condition that the pressure at the inlet of the overflow valve (3) is not less than the opening pressure of the overflow valve (3), the speed of the power pump (1) is reduced to reduce the output flow, so that the pressure at the inlet of the overflow valve (3) is less than the overflow pressure.

7. The overflow prevention method according to claim 6, characterized in that, After determining that the pressure at the inlet of the relief valve (3) is not less than the opening pressure of the relief valve (3), and controlling the power pump (1) to reduce its speed to reduce the output flow, the method further includes: When the pressure at the inlet of the overflow valve (3) remains unchanged or continues to increase, the power pump (1) is controlled to depressurize.

8. The overflow prevention method according to claim 6, characterized in that, Also includes: When the actuator (2) extends from the initial position to the limit position, and when the actuator (2) extends to the working position, the power pump (1) is controlled to reduce the speed to reduce the output flow, so that the pressure of the overflow valve (3) is less than the overflow pressure. The extension position of the actuator (2) when the pressure at the inlet end of the overflow valve (3) is greater than the opening pressure of the overflow valve (3) is the working position.

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