Opening and closing hydraulic system and control method

Abstract

The invention discloses an opening and closing hydraulic system and a control method. The system comprises an oil cylinder, an oil tank, an energy accumulator, a pump set, a detection module, an opening and closing loop and an adjusting loop. The connecting end of the opening and closing loop is connected with a rod cavity and a rodless cavity of the oil cylinder, and an oil inlet of the opening and closing loop is in redundant connection with the energy accumulator and the pump set. The detection module is used for monitoring the slurry outlet amount of a material opening and the position of an oil cylinder; the adjusting loop is connected to the opening and closing loop in parallel and suitable for controlling the oil cylinder to adjust the opening degree of the material opening according to the monitoring result of the detection module. The method is applied to the system. The device has the beneficial effects that the opening degree of the material opening can be accurately controlled through the adjusting loop, and manual adjustment is not needed; and closed-loop control is performed through the flow rate of slurry at the material port, the opening degree of the material port is adjusted in real time, and the stability of the discharging amount is ensured.

Description

Technical Field

[0001] The present application relates to the field of hydraulic technology, and in particular to a starting and closing hydraulic system and a control method. Background Art

[0002] When conveying slurry, for slurry conveying systems with special requirements and large flow rates, the conveying pipeline will be equipped with a valve port adjustment system to control the amount of slurry conveyed. The valve port adjustment system generally adopts a manual mechanical structure, or a switch-type multi-point control method to adjust the size and opening and closing of the material port.

[0003] However, the prior art has the following problems when adjusting the material port:

[0004] (1) The existing slurry outlet channel cannot be accurately positioned and adjusted, resulting in a large deviation in the slurry outlet amount.

[0005] (2) When the incoming material is uneven or a blockage occurs, it cannot be adjusted in real time.

[0006] (3) When the machine is shut down or the oil pump fails, it is impossible to achieve long-term pressure locking, which in turn affects production efficiency. Summary of the invention

[0007] One of the purposes of the present application is to provide a hydraulic system for opening and closing that can solve at least one of the defects in the above-mentioned background technology.

[0008] Another object of the present application is to provide a control method for an opening and closing hydraulic system that can solve at least one defect in the above-mentioned background technology.

[0009] In order to achieve at least one of the above-mentioned purposes, the technical solution adopted in the present application is: a starting and closing hydraulic system, including a cylinder, an oil tank, an accumulator, a pump group, a detection module, an open and closed circuit and a regulating circuit; the cylinder controls the opening and closing of the material port by extending and contracting respectively; the connecting ends of the open and closed circuit are respectively connected to the rod chamber and the rodless chamber of the cylinder, the oil inlet of the open and closed circuit is redundantly connected to the accumulator and the pump group, and the oil outlet of the open and closed circuit is connected to the oil tank; the accumulator is suitable for supplying oil or maintaining pressure to the cylinder when the pump group is abnormal; the detection module is used to monitor the slurry discharge volume of the material port and the position of the cylinder; the regulating circuit is connected in parallel to the open and closed circuit, and the regulating circuit is suitable for controlling the cylinder to adjust the opening of the material port according to the monitoring result of the detection module.

[0010] Preferably, the open and closed circuit includes a first solenoid reversing valve, a pair of second hydraulically controlled one-way valves and a pair of one-way throttle valves; the connecting port of the first solenoid reversing valve is connected to the rodless chamber and the rod chamber of the cylinder through a pair of pipelines respectively; the second hydraulically controlled one-way valve and the one-way throttle valve are connected in series on each pipeline, and the control end of the second hydraulically controlled one-way valve is connected to another pipeline; the oil inlet of the first solenoid reversing valve is redundantly connected to the accumulator and the pump group respectively, and the oil outlet of the first solenoid reversing valve is connected to the oil tank.

[0011] Preferably, the regulating circuit includes a proportional valve and a pair of reversing valves; the oil inlet of the proportional valve is connected in parallel with the oil inlet of the first electromagnetic reversing valve, the oil outlet of the proportional valve is connected to the oil tank, and the two connecting ports of the proportional valve are respectively connected to the rod chamber and the rodless chamber of the cylinder through the reversing valves connected in series; when the opening of the material port is adjusted, the first electromagnetic reversing valve is cut off, the reversing valve is turned on, and the proportional valve controls the flow of the pumped oil according to the opening adjustment amount of the material port.

[0012] Preferably, the reversing valve adopts a hydraulically controlled reversing valve, and the regulating circuit also includes a second solenoid reversing valve, the oil inlet and oil outlet of the second solenoid reversing valve are respectively connected in parallel with the oil inlet and oil outlet of the first solenoid reversing valve, and the connecting port of the second solenoid reversing valve is respectively connected to the control ends of the two hydraulically controlled reversing valves.

[0013] Preferably, the pump group includes a first oil pump, a second oil pump and a manual pump; the input ends of the first oil pump, the second oil pump and the manual pump extend to the oil tank, and the output ends of the first oil pump, the second oil pump and the manual pump are connected in parallel to the oil inlet of the first solenoid reversing valve; the first oil pump is suitable for supplying oil to the open and closed circuit, or replenishing oil to the accumulator when the pressure of the accumulator is lower than the set value; the manual pump is suitable for replacing the first oil pump for oil supply through manual operation when the first oil pump fails; the rated flow of the second oil pump is less than the rated flow of the first oil pump, and the second oil pump is suitable for supplying oil to the regulating circuit alone when adjusting the opening of the material inlet.

[0014] Preferably, the output end of the accumulator is connected in parallel with the output end of the pump group through a first hydraulically controlled one-way valve connected in series, and a first electromagnetic ball valve is installed on the reverse conducting circuit formed by connecting the control end of the first hydraulically controlled one-way valve and the output end of the accumulator; the first electromagnetic ball valve controls the reverse conducting circuit to be cut off when the pump group is working, and then the accumulator is isolated from the open and closed circuit through the first hydraulically controlled one-way valve; when the pump group stops due to an abnormality, the first electromagnetic ball valve controls the reverse conducting circuit to be turned on, and then the accumulator supplies oil to the open and closed circuit.

[0015] Preferably, the accumulator also quickly closes the material port in an emergency state through an emergency circuit; the emergency circuit includes a first logic valve, a second logic valve and a manual ball valve; the first logic valve is connected between the rod chamber of the cylinder and the accumulator, the second logic valve is connected between the rodless chamber of the cylinder and the oil tank, the control ends of the first logic valve and the second logic valve are connected to the accumulator, and are connected to the oil tank through the manual ball valve, so that in an emergency state, the control oil of the first logic valve and the second logic valve can be returned to the oil tank through manual operation of the manual ball valve, thereby opening the main oil circuit of the first logic valve and the second logic valve; at this time, the first solenoid ball valve controls the reverse conducting circuit to be cut off.

[0016] Preferably, a pair of second electromagnetic ball valves are connected between the rodless chamber of the oil cylinder and the accumulator, and the second electromagnetic ball valves are connected in series to form a pressure-maintaining branch for maintaining pressure on the material gate; the control ends of the first logic valve and the second logic valve are both connected to the midpoint of the pressure-maintaining branch, so that when the pressure-maintaining branch is turned on, control oil is delivered to the control ends of the first logic valve and the second logic valve to perform cut-off locking; when the emergency circuit is turned on, the second electromagnetic ball valve close to the accumulator remains cut off.

[0017] A control method for the above-mentioned opening and closing hydraulic system comprises the following steps:

[0018] S100: Calculate the slurry discharge amount according to the collected discharge flow rate of the material outlet and the stroke of the oil cylinder;

[0019] S200: Compare the calculated slurry discharge amount with the set value, convert the difference between the two into an opening signal and send it to the regulating loop, thereby controlling the oil cylinder to extend or retract to adjust the opening of the material port;

[0020] S300: When the pump group stops working, the duration of the material gate pressure maintenance and the number of times the material gate is opened and closed are predicted based on the performance and structural parameters of the accumulator and the oil cylinder.

[0021] Preferably, in step S100, the calculation formula of the pulp output M is:

[0022]

[0023] Wherein, A represents the opening area of ​​the material port, which is equal to the product of the cylinder stroke L and the opening coefficient a; v(t) represents the relationship between the slurry flow rate v at the material port and the time t; t1 and t2 represent the two interval recording moments of the slurry flow rate at the material port respectively;

[0024] In step S300, the pressure holding duration T of the material gate is equal to the pressure holding end time t4 minus the pressure holding start time t3. The specific prediction calculation formula is as follows:

[0025]

[0026] Among them, ΔV represents the working volume of the accumulator, and S(t) represents the relationship between the cylinder leakage S and time t;

[0027] In step S300, the prediction calculation formula for the opening and closing times N of the material door is as follows:

[0028]

[0029] Among them, V0 represents the volume of the accumulator, p0 represents the charging pressure of the accumulator, p1 represents the minimum pressure of the accumulator, p2 represents the real-time pressure of the accumulator, and n represents the index.

[0030] Compared with the prior art, the beneficial effects of this application are:

[0031] (1) The size of the feed inlet opening can be precisely controlled through the regulating loop without manual adjustment; and the flow rate of the slurry at the feed inlet is controlled in a closed loop, and the feed inlet opening is adjusted in real time to ensure the stability of the discharge amount.

[0032] (2) By adding an accumulator as an auxiliary power source, the material door can be opened and closed normally in a power-off state, and the specific auxiliary control duration is predictable. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the hydraulic control system in this application.

[0034] Figure 2 Schematic diagram of the workflow of the control method in this application.

[0035] In the figure: oil tank 1, first oil pump 2, second oil pump 3, manual pump 4, first electromagnetic ball valve 5, first hydraulically controlled one-way valve 6, first electromagnetic reversing valve 7, pressure reducing valve 8, second electromagnetic reversing valve 9, throttle valve 10, proportional valve 11, second hydraulically controlled one-way valve 12, one-way throttle valve 13, accumulator 14, second electromagnetic ball valve 15, first logic valve 16, manual ball valve 17, hydraulically controlled reversing valve 18, second logic valve 19, manual valve 20, speed regulating valve 21, oil cylinder 22, displacement sensor 23, flow sensor 24. DETAILED DESCRIPTION

[0036] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0037] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present application.

[0038] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0039] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0041] The terms "including" and "having" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0042] One aspect of the present application provides a hydraulic system for opening and closing the valve. Figure 1 As shown, one of the preferred embodiments of the present application includes a cylinder 22, a fuel tank 1, an accumulator 14, a pump group, a detection module, an open-closed loop and a regulating loop. During the slurry conveying process, the opening of the material port for slurry conveying is controlled by the opening and closing of the material gate, and the material gate can be connected to the driving end of the cylinder 22 so that the material gate can control the opening and closing of the material port under the extension and contraction of the cylinder 22. The connecting ends of the open-closed loop are respectively connected to the rod chamber and the rodless chamber of the cylinder 22, the oil inlet of the open-closed loop is redundantly connected to the accumulator 14 and the pump group, and the oil outlet of the open-closed loop is connected to the fuel tank 1, so that when the opening of the material port is adjusted, the accumulator 14 can supply oil or maintain pressure to the cylinder 22 when the pump group is abnormal. The detection module is used to monitor the slurry discharge amount of the material port and the position of the cylinder 22; the regulating loop is connected in parallel to the open-closed loop, and the regulating loop can control the cylinder 22 to adjust the opening of the material port according to the monitoring results of the detection module.

[0043] It is understandable that the traditional hydraulic system for controlling the opening of the material port for slurry transportation only includes an open-closed circuit and a pump group. The opening and closing of the material gate and the opening adjustment of the material port are achieved by the pump group supplying oil to the open-closed circuit. Since the material gate needs to be fully opened and closed, the setting of the traditional pump group is generally designed according to the fully open state of the material gate, that is, the output flow of the traditional pump group is relatively large, which leads to poor accuracy when the opening of the material port is directly adjusted through the open-closed circuit, and thus cannot achieve good control of the slurry transportation amount. At the same time, the traditional hydraulic system for slurry transportation lacks fault protection function, that is, after the pump group fails or the power is off, the material gate will lose control, which will reduce the safety of slurry transportation.

[0044] In this embodiment, an independent regulating loop is set on the basis of the traditional open and closed loop, and the regulating loop can control the flow delivered by the pump group, and then can realize the micro-stroke control of the oil cylinder 22 through the oil with a smaller flow rate, that is, realize the precise control of the opening of the material port. At the same time, the present application also sets an accumulator 14 redundantly connected to the pump group, so that when the pump group fails or the power is off, the accumulator 14 can replace the pump group to supply oil to the oil cylinder 22. In addition, the accumulator 14 can also maintain the pressure of the material gate in all states of the material port.

[0045] Specifically, when the pump group is in normal operation, the opening and closing control of the material port can be controlled by the pump group supplying oil to the open and closed circuit. If the pump group fails or loses power, the pump group will stop working. At this time, the accumulator 14 can supply oil to the open and closed circuit to control the stroke of the oil cylinder 22, and then control the opening of the material port. When the material port is fully open, it means that the slurry delivery volume is relatively large at this time. At this time, the pressure between the rod chamber and the rodless chamber of the oil cylinder 22 is maintained by the open and closed circuit. However, there may be leakage in the hydraulic system, which causes the material gate to gradually move in the direction of closing the material port over time. If the pump group is always used for oil replenishment, on the one hand, the pump group needs to be started and stopped frequently, which will affect the service life of the pump group. The accumulator 14 can continuously replenish oil to the oil cylinder 22 according to its own working characteristics, so that the material gate can always maintain a stable fully open state.

[0046] It should also be known that since the accumulator 14 replenishes oil to the oil cylinder 22, the output pressure of the accumulator 14 will gradually decrease. When the output pressure of the accumulator 14 is lower than a set threshold, the pump group can also replenish oil and charge the accumulator 14.

[0047] In this embodiment, there are many specific structures of the open and closed loop that can achieve the above functions. For the sake of easy understanding, one of the structures will be used for detailed description below. Figure 1As shown, the open-closed circuit includes a first electromagnetic reversing valve 7, a pair of second hydraulically controlled one-way valves 12 and a pair of one-way throttle valves 13. The connecting port of the first electromagnetic reversing valve 7 is connected to the rodless chamber and the rod chamber of the oil cylinder 22 through a pair of pipelines. The second hydraulically controlled one-way valve 12 and the one-way throttle valve 13 are connected in series on each pipeline, and the control end of the second hydraulically controlled one-way valve 12 is connected to another pipeline, so that when one pipeline supplies oil to the oil cylinder 22, the second hydraulically controlled one-way valve 12 of the other pipeline can be opened in reverse, thereby facilitating the oil in the oil cylinder 22 to flow back to the oil tank 1. The oil inlet of the first electromagnetic reversing valve 7 is redundantly connected to the accumulator 14 and the pump group, respectively, and the oil outlet of the first electromagnetic reversing valve 7 is connected to the oil tank 1.

[0048] It should be known that the specific structures and working principles of the first electromagnetic reversing valve 7, the second hydraulically controlled one-way valve 12 and the one-way throttle valve 13 are well known to those skilled in the art, so they will not be elaborated in detail here. Among them, the first electromagnetic reversing valve 7 preferably adopts a Y-type three-dimensional four-way reversing valve, and the two control ends of the first electromagnetic reversing valve 7 can be defined as YV2 and YV3 respectively. Figure 1 As shown, when the control terminal YV2 is powered, the oil provided by the pump group or accumulator 14 can enter the rodless chamber of the oil cylinder 22, and the oil in the rod chamber of the oil cylinder 22 flows back to the oil tank 1 through the oil outlet, so that the oil cylinder 22 extends to control the material door to open. When the control terminal YV3 is powered, the oil provided by the pump group or accumulator 14 can enter the rod chamber of the oil cylinder 22, and the oil in the rodless chamber of the oil cylinder 22 flows back to the oil tank 1 through the oil outlet, so that the oil cylinder 22 contracts to control the material door to close. When both the control terminal YV2 and the control terminal YV3 are not powered, the oil inlet of the first electromagnetic reversing valve 7 is cut off, and the oil cylinder 22 is in a pressure-maintaining state through the second hydraulically controlled one-way valve 12.

[0049] It should be noted that when the material gate is opened, the pressure of the slurry feeding gate is in the direction of the material gate opening, that is, the slurry feeding gate is a pressure that produces an opening tendency. Therefore, during the opening process of the material gate, that is, the extension process of the oil cylinder 22, the opening speed of the material gate does not need to be limited; while during the closing process of the material gate, that is, the contraction process of the oil cylinder 22, the slurry will produce an impact force on the material gate, making the resistance of the material gate when closing quickly extremely large, so the closing process of the material gate needs to be carried out slowly. In this embodiment, the speed regulating valve 21 can be installed in the rod chamber or rodless chamber position of the oil cylinder 22 to realize the control of the contraction speed of the oil cylinder 22; in this embodiment, the speed regulating valve 21 is preferably installed in the rodless chamber of the oil cylinder 22.

[0050] In this embodiment, there are multiple specific structures of the regulating circuit that can realize the above functions. For the convenience of understanding, one of the structures will be described in detail below. The regulating circuit includes a proportional valve 11 and a pair of reversing valves; the oil inlet of the proportional valve 11 is connected in parallel with the oil inlet of the first electromagnetic reversing valve 7, the oil outlet of the proportional valve 11 is connected to the oil tank 1, and the two connecting ports of the proportional valve 11 are respectively connected to the rod chamber and the rodless chamber of the oil cylinder 22 through the reversing valves connected in series. When the opening of the material port is adjusted, the first electromagnetic reversing valve 7 is turned off, the reversing valve is turned on, and the proportional valve 11 controls the flow of the pumped oil according to the opening adjustment amount of the material port.

[0051] It can be understood that the proportional valve 11 is a proportional reversing valve, which is a reversing valve that can accurately control the hydraulic flow and direction. Its specific structure and working principle are well-known to those skilled in the art, so they will not be elaborated in detail here. In this embodiment, the proportional valve 11 preferably adopts a Y-type three-position four-way proportional reversing valve; then the two control ends of the proportional valve 11 can be defined as YVa and YVb respectively. Figure 1 As shown, when the control terminal YVa is powered, the oil provided by the pump group or accumulator 14 can enter the rod chamber of the oil cylinder 22, and the oil in the rodless chamber of the oil cylinder 22 flows back to the oil tank 1 through the oil outlet, so that the oil cylinder 22 contracts to control the reduction of the opening of the material port. When the control terminal YVb is powered, the oil provided by the pump group or accumulator 14 can enter the rodless chamber of the oil cylinder 22, and the oil in the rod chamber of the oil cylinder 22 flows back to the oil tank 1 through the oil outlet, so that the oil cylinder 22 extends to control the increase of the opening of the material port. When both the control terminal YVa and the control terminal YVb are not powered, the oil inlet of the proportional valve 11 is cut off, and at this time, the oil cylinder 22 is in a material port opening holding state through the reversing valve.

[0052] It should be known that the specific structure and working principle of the reversing valve are also well known to those skilled in the art, so they will not be elaborated in detail here. The function of the reversing valve is to realize the conduction or cutoff of the regulating circuit to prevent the oil from flowing back from the regulating circuit when the oil cylinder 22 is performing other work. There are many specific types of reversing valves that can realize this function. For the sake of easy understanding, a specific example will be used for detailed description below.

[0053] Specifically, Figure 1As shown, the reversing valve adopts a hydraulically controlled reversing valve 18, and the regulating circuit also includes a second electromagnetic reversing valve 9. The oil inlet and oil outlet of the second electromagnetic reversing valve 9 are respectively connected in parallel with the oil inlet and oil outlet of the first electromagnetic reversing valve 7, and the connecting port of the second electromagnetic reversing valve 9 is respectively connected to the control ends of the two hydraulically controlled reversing valves 18, so that the hydraulically controlled reversing valve 18 can be pilot-controlled by the second electromagnetic reversing valve 9. When the opening of the material port needs to be fine-tuned, the oil provided by the pump group or the accumulator 14 can be first delivered to the second electromagnetic reversing valve 9, and then the second electromagnetic reversing valve 9 can deliver the oil to the control end of the hydraulically controlled reversing valve 18 to conduct the regulating circuit. Subsequently, part of the oil provided by the pump group or the accumulator 14 keeps the regulating circuit conducting, and the remaining oil flows to the oil cylinder 22 along the conducting proportional valve 11.

[0054] It can be understood that since the amount of oil required by the control end of the hydraulically controlled reversing valve 18 is less than the amount of oil supplied when the cylinder 22 is fine-tuned for opening, a throttle valve 10 needs to be provided at the connecting end of the second solenoid reversing valve 9 to reduce the amount of oil delivered to the control end of the hydraulically controlled reversing valve 18, so as to avoid damage to the control end of the hydraulically controlled reversing valve 18 due to overload.

[0055] It should be known that the specific structures and working principles of the second electromagnetic reversing valve 9, the hydraulic control reversing valve 18 and the throttle valve 10 are well-known technologies to those skilled in the art, so they will not be elaborated in detail here. In this embodiment, the second electromagnetic reversing valve 9 preferably adopts a Y-type three-position four-way reversing valve with the same structure as the first electromagnetic reversing valve 7, and the two control ends of the second electromagnetic reversing valve 9 can be defined as YV4 and YV5 respectively. The hydraulic control reversing valve 18 preferably adopts a two-position two-way reversing valve. The hydraulic control reversing valve 18 has a one-way conduction function toward the direction of the oil cylinder 22 in the natural state. The hydraulic control reversing valve 18 can be conducted along the oil return direction of the oil cylinder 22 under the drive of the control end.

[0056] If Figure 1 As shown, when the opening of the material port needs to be increased, the control end YV5 of the second electromagnetic reversing valve 9 is energized, and the oil can control the hydraulic control reversing valve 18 connected to the rod chamber of the oil cylinder 22 to move. At this time, the oil output by the proportional valve 11 can flow along the hydraulic control reversing valve 18 connected to the rodless chamber to the rodless chamber of the oil cylinder 22, and the oil in the rod chamber can flow back to the oil tank 1 along the hydraulic control reversing valve 18 connected thereto. When the opening of the material port needs to be reduced, the control end YV4 of the second electromagnetic reversing valve 9 is energized, and the oil can control the hydraulic control reversing valve 18 connected to the rodless chamber of the oil cylinder 22 to move. At this time, the oil output by the proportional valve 11 can flow along the hydraulic control reversing valve 18 connected to the rod chamber to the rod chamber of the oil cylinder 22, and the oil in the rodless chamber can flow back to the oil tank 1 along the hydraulic control reversing valve 18 connected thereto.

[0057] In this embodiment, Figure 1 As shown, in order to further reduce the oil pressure delivered to the second solenoid reversing valve 9 by the pump group or the accumulator 14, a pressure reducing valve 8 can be installed at the oil inlet of the second solenoid reversing valve 9. The pressure reducing valve 8 can also be hydraulically controlled. The control end of the pressure reducing valve 8 is connected to the oil return port of the second solenoid reversing valve 9, so that when the pressure at the oil return port is too high, the oil inlet pressure can be reduced.

[0058] In this embodiment, Figure 1 As shown, the pump group includes a first oil pump 2, a second oil pump 3 and a manual pump 4. The input ends of the first oil pump 2, the second oil pump 3 and the manual pump 4 extend to the oil tank 1, and the output ends of the first oil pump 2, the second oil pump 3 and the manual pump 4 are connected in parallel to the oil inlet of the first electromagnetic reversing valve 7. The first oil pump 2 can supply oil to the open and close circuit to control the opening and closing of the material port, or replenish the oil to the accumulator 14 when the pressure is lower than the set value; the manual pump 4 can replace the first oil pump 2 to supply oil through manual operation when the first oil pump 2 fails; the rated flow of the second oil pump 3 is less than the rated flow of the first oil pump 2, and the second oil pump 3 can supply oil to the regulating circuit alone when adjusting the opening of the material port.

[0059] It should be known that the specific structures and working principles of the first oil pump 2, the second oil pump 3 and the manual pump 4 are well-known technologies to those skilled in the art, so they will not be elaborated in detail here; the first oil pump 2 and the second oil pump 3 preferably use motor oil pumps.

[0060] It is understandable that if both the open and closed loop and the regulating loop are supplied with oil through the first oil pump 2, then the first oil pump 2 must be designed based on the open and closed loop, so that when the first oil pump 2 supplies oil to the regulating loop, the first oil pump 2 needs to work in a low-power state, and in multiple regulation scenarios with multiple feed ports, multiple intermittent low-power starts of the first oil pump 2 will affect the service life of the first oil pump 2. Therefore, this embodiment uses a second oil pump 3 with a rated flow rate less than the first oil pump 2 to achieve separate oil supply to the regulating loop, which can effectively protect the first oil pump 2, and the second oil pump 3 can also work in a normal state.

[0061] In this embodiment, Figure 1 As shown, the output end of the accumulator 14 is connected in parallel with the output end of the pump group through the first hydraulically controlled one-way valve 6 connected in series, and the first electromagnetic ball valve 5 is installed on the reverse conducting circuit formed by connecting the control end of the first hydraulically controlled one-way valve 6 and the output end of the accumulator 14. The first electromagnetic ball valve 5 controls the reverse conducting circuit to be cut off when the pump group is working, and then the accumulator 14 is isolated from the open and closed circuit through the first hydraulically controlled one-way valve 6; when the pump group stops due to abnormalities such as failure or power failure, the first electromagnetic ball valve 5 controls the reverse conducting circuit to be turned on, and then the accumulator 14 supplies oil to the open and closed circuit.

[0062] It is understandable that the accumulator 14 is an active power source, so in order to ensure that the accumulator 14 can be in a non-operating state when the pump group is working, the accumulator 14 needs to be cut off in the output direction. When the pump group is abnormal, the accumulator 14 needs to perform output work, and the accumulator 14 also needs the pump group to replenish oil under low pressure. Then the output end of the accumulator 14 and the output end of the pump group need to be controlled by a reversing conductive element. There are many types of reversing conductive elements that can achieve the above functions. In this embodiment, the first hydraulically controlled one-way valve 6 is preferably used.

[0063] The first hydraulically controlled one-way valve 6 is in a conducting state in the direction of the pump group replenishing oil to the accumulator 14, and is in a natural shutoff state in the output direction of the accumulator 14. Since the accumulator 14 needs to work when the pump group is shut down, the control end of the first hydraulically controlled one-way valve 6 must be connected to the output end of the accumulator 14. Since the accumulator 14 continuously outputs pressure, the control end of the first hydraulically controlled one-way valve 6 cannot be directly connected, and must be controlled and connected through a control valve. In this embodiment, the first electromagnetic ball valve 5 is preferably used for the control valve. In this way, when the accumulator 14 is required to work, the first electromagnetic ball valve 5 can conduct the control end of the first hydraulically controlled one-way valve 6, and then the first hydraulically controlled one-way valve 6 will reversely conduct under the pressure of the accumulator 14. When the accumulator 14 is not required to work, the first electromagnetic ball valve 5 can cut off the control end of the first hydraulically controlled one-way valve 6, and then the first hydraulically controlled one-way valve 6 only has a one-way conduction function, so that the output of the accumulator 14 is isolated.

[0064] It should be known that the specific structure and working principle of the first electromagnetic ball valve 5 are well known to those skilled in the art, so they will not be elaborated in detail here; there are many specific types of the first electromagnetic ball valve 5, and a two-position three-way electromagnetic valve is preferably used in this embodiment. Figure 1 As shown, the control end of the first electromagnetic ball valve 5 can be defined as YV1. When the accumulator 14 is not needed to work, the first electromagnetic ball valve 5 loses power, and the control end of the first hydraulically controlled one-way valve 6 is cut off; when the accumulator 14 is needed to work, the first electromagnetic ball valve 5 is energized, and the control end of the first hydraulically controlled one-way valve 6 is turned on.

[0065] In this embodiment, when the material door needs to be quickly closed in an emergency, it can be seen from the above content that the opening and closing circuit may require reverse driving of the pump group and the switching process of the valve to achieve it, which will cause a delay in the rapid closing of the material door. Therefore, in this embodiment, an independent emergency circuit can be set between the accumulator 14 and the oil cylinder 22, so that in an emergency, the emergency circuit only needs to switch the valve to achieve the rapid contraction of the oil cylinder 22.

[0066] Specifically, Figure 1As shown, the emergency circuit includes a first logic valve 16, a second logic valve 19 and a manual ball valve 17; the first logic valve 16 is connected between the rod chamber of the cylinder 22 and the accumulator 14, the second logic valve 19 is connected between the rodless chamber of the cylinder 22 and the oil tank 1, and the control ends of the first logic valve 16 and the second logic valve 19 are connected to the accumulator 14, and are connected to the oil tank 1 through the manual ball valve 17.

[0067] When the oil cylinder 22 is in a normal working state, the oil output by the accumulator 14 can flow to the control end of the first logic valve 16 and the second logic valve 19, so that the first logic valve 16 and the second logic valve 19 are in a closed state, that is, the emergency circuit is in a cut-off state at this time. When the material port needs to be quickly closed in an emergency state, that is, the oil cylinder 22 needs to be quickly retreated, the control oil of the first logic valve 16 and the second logic valve 19 is returned to the oil tank 1 through the manual operation of the manual ball valve 17, and then the main oil circuit of the first logic valve 16 and the second logic valve 19 will be opened, and then the oil output by the accumulator 14 can flow to the rod chamber of the oil cylinder 22 through the first logic valve 16, and at the same time, the oil in the rodless chamber of the oil cylinder 22 will flow to the oil tank along the second logic valve 19. At this time, the first electromagnetic ball valve 5 controls the reverse conduction circuit to be cut off, so that the accumulator 14 only works in the emergency circuit.

[0068] It can be understood that, in this embodiment, for the emergency state of closing the material port, it is only necessary to manually operate the manual ball valve 17 to release the oil from the control ends of the first logic valve 16 and the second logic valve 19, without other operation steps, which can effectively improve the closing speed of the material port in the emergency state. The specific structures and working principles of the first logic valve 16, the second logic valve 19 and the manual ball valve 17 are well known to those skilled in the art, so they will not be elaborated in detail here.

[0069] In this embodiment, in order to adjust the retraction speed of the oil cylinder 22 in an emergency state, a speed regulating valve 21 can be installed at the connection position between the emergency circuit and the rodless chamber of the oil cylinder 22. The number of speed regulating valves 21 can be set to multiple to meet different retraction speed requirements. Multiple speed regulating valves 21 can be set in parallel with each other. The number of speed regulating valves 21 can be set to X, and X-1 speed regulating valves 21 are installed in series with manual valves 20, so that when adjusting different retraction speeds of the oil cylinder 22, the number of speed regulating valves 21 connected can be controlled by operating the manual valve 20. The specific structure and working principle of the manual valve 20 are well known to those skilled in the art, so they will not be elaborated in detail here.

[0070] In this embodiment, the pressure-maintaining branch adopted by the accumulator 14 to maintain the pressure of the material gate, that is, to maintain the pressure of the oil cylinder 22, is independent of the open-closed circuit, which can effectively reduce the complexity of the open-closed circuit. There are many specific structures of the pressure-maintaining branch that can achieve the pressure-maintaining function. For the sake of easy understanding, one of the structures will be described in detail below. Figure 1 As shown, a pair of second electromagnetic ball valves 15 are connected between the rodless chamber of the oil cylinder 22 and the accumulator 14, and the second electromagnetic ball valves 15 are connected in series to form a pressure-maintaining branch for maintaining pressure on the material gate. The control ends of the first logic valve 16 and the second logic valve 19 are both connected to the midpoint of the pressure-maintaining branch, so that when the pressure-maintaining branch is turned on, control oil is delivered to the control ends of the first logic valve 16 and the second logic valve 19 for cut-off locking; when the emergency circuit is turned on, the second electromagnetic ball valve 15 close to the accumulator 14 remains cut off, thereby preventing the pressure-maintaining branch from interfering with the emergency circuit.

[0071] It is understandable that the specific structure and working principle of the second electromagnetic ball valve 15 are well known to those skilled in the art, so they will not be elaborated in detail here; in this embodiment, the second electromagnetic ball valve 15 preferably adopts a two-position two-way electromagnetic valve. Among them, the control end of the second electromagnetic ball valve 15 connected to the accumulator 14 is defined as YV7, and the control end of the second electromagnetic ball valve 15 connected to the rodless chamber of the oil cylinder 22 is defined as YV6. The second electromagnetic ball valve 15 connected to the accumulator 14 is turned on in the power-off state, and the second electromagnetic ball valve 15 connected to the rodless chamber of the oil cylinder 22 is cut off in the power-off state. When the emergency circuit is working, the control end YV7 is energized to make the second electromagnetic ball valve 15 connected to the accumulator 14 cut off; when the pressure of the material gate needs to be maintained, the control end YV7 is de-energized, and the control end YV6 is energized, so that the two second electromagnetic ball valves 15 are both passed, and then the oil in the accumulator 14 can be transported to the rodless chamber of the oil cylinder 22 after passing through the two second electromagnetic ball valves 15.

[0072] Another aspect of the present application provides a control method applied to the above-mentioned on-off hydraulic system, such as Figure 2 As shown, one of the preferred embodiments includes the following steps:

[0073] S100: The slurry discharge amount is calculated based on the collected discharge flow rate of the material outlet and the stroke of the oil cylinder 22.

[0074] S200: Compare the calculated slurry output with the set value, convert the difference between the two into an opening signal and send it to the regulating loop, thereby controlling the oil cylinder 22 to extend or retract to adjust the opening of the material port.

[0075] S300: When the pump group stops working, the duration of the material gate pressure maintenance and the number of times the material gate is opened and closed are predicted according to the performance and structural parameters of the accumulator 14 and the oil cylinder 22.

[0076] It is understandable that in order to ensure that the opening of the material port is adjusted accurately, the present embodiment can obtain an accurate slurry discharge amount by integrating the discharge flow rate of the material port and the stroke of the oil cylinder 22. At this time, it is only necessary to compare the calculated slurry discharge amount with the set slurry discharge amount to know whether the slurry delivery meets the requirements; for the slurry discharge amount that does not meet the requirements, the opening of the material port can be adjusted according to the difference between the actual value and the calculated value to achieve compensation for the slurry discharge amount. Specifically, if the actual slurry discharge amount exceeds the amount, the opening of the material port needs to be reduced, otherwise the opening of the material port needs to be increased.

[0077] At the same time, when the pump group fails to work due to an abnormality, the pressure holding time of the accumulator 14 can be predicted based on the known parameters of the oil cylinder 22 and the parameters of the accumulator 14. This can provide the staff with a predicted system safety time and remind the staff to take protective and repair measures in time within the safety time.

[0078] In this embodiment, there are multiple specific structures of the detection module for monitoring the discharge flow rate of the material port and the stroke of the oil cylinder 22. For ease of understanding, a detailed description will be given below using one of the structures. Figure 1 As shown, the detection module includes a displacement sensor 23 and a flow sensor 24. The displacement sensor 23 is installed on the piston rod of the oil cylinder 22 to monitor the stroke of the oil cylinder 22, and the flow sensor 24 is set at the material inlet position to monitor the flow rate of the slurry. The specific structure and working principle of the displacement sensor 23 and the flow sensor 24 are well-known technologies for those skilled in the art, so they will not be elaborated in detail here.

[0079] To derive the calculation formula for the slurry discharge amount M, we can assume that the opening area of ​​the material port is A and the stroke of the cylinder 22 is L; the opening area of ​​the material port is affected by the opening degree of the material door, and the opening degree of the material door is controlled by the stroke of the cylinder 22. The two can be regarded as a linear relationship, and we can get A=aL; where a represents the opening coefficient related to the stroke of the cylinder 22 and the opening degree of the material door.

[0080] It should be noted that the slurry flow rate at the material port may change with time, and it can be recorded by the flow sensor 24, so as to obtain a curve of the slurry flow rate v with respect to time t, which can be represented by the relationship v(t). Then for the slurry discharge M, it is only necessary to integrate the relationship v(t) over the duration. The calculation formula for the slurry discharge M is:

[0081]

[0082] Among them, t1 and t2 represent the two interval recording moments of the slurry flow rate at the material outlet.

[0083] After calculating the slurry discharge amount M, it can be compared with the set value M0 in step S200, and the specific value of M0 can be set according to the actual needs of the technicians in this field. If M>M0, the reduction in the opening area of ​​the material port can be reversed according to the difference between the two and the duration that needs to be compensated, that is, the reduction in the opening, which can be converted into the stroke contraction of the cylinder 22 according to the aforementioned formula, and finally converted into the control signal of the proportional valve 11. If M<M0, the increase in the opening area of ​​the material port can be reversed according to the difference between the two and the duration that needs to be compensated, that is, the increase in the opening, which can be converted into the stroke extension of the cylinder 22 according to the aforementioned formula, and finally converted into the control signal of the proportional valve 11.

[0084] It is understandable that the prediction of the pressure holding time in step S300, that is, the longest pressure holding time is the duration of the leakage compensation of the system using the full working pressure of the accumulator 14. Assuming that only the oil cylinder 22 leaks during the pressure holding, the pressure holding duration T of the material gate is related to the leakage amount S of the oil cylinder 22. Since the leakage amount S of the oil cylinder 22 may change with time, it can be expressed by the relationship S(t) between the leakage amount S of the oil cylinder 22 and the time t, and then the required pressure holding duration T can be calculated by integration. The specific prediction calculation formula is as follows:

[0085]

[0086] Wherein, ΔV represents the working volume of the accumulator 14 , and the pressure-maintaining duration T is equal to the pressure-maintaining end time t4 minus the pressure-maintaining start time t3 .

[0087] It should be known that the curve of the leakage amount S of the oil cylinder 22 versus time t can be detected by pressure sensors disposed at the output end of the oil cylinder 22 and the output end of the accumulator 14 .

[0088] During the pressure maintenance process, the material gate may be closed and reopened according to the actual working conditions of the slurry, and the accumulator 14 needs to lose some pressure each time the material gate is opened and closed, which leads to a decrease in the pressure maintenance duration T. Therefore, when the accumulator 14 is performing pressure maintenance work under abnormal or emergency conditions of the pump group, the material gate cannot be opened and closed too many times. The number of times the material gate can be opened and closed can be calculated by a prediction formula. The derivation process of the calculation formula that can predict the number of times the material gate is opened and closed N is as follows:

[0089] The accumulator 14 is used as an auxiliary power source, and the relationship between its working volume ΔV and pressure is (1):

[0090]

[0091] Wherein, V0 represents the volume of the accumulator 14, p0 represents the charging pressure of the accumulator 14, p1 represents the minimum pressure of the accumulator 14, p2 represents the real-time pressure of the accumulator 14, and n represents an index.

[0092] It should be noted that each time the material door is opened and closed, the oil cylinder 22 needs to consume a whole working volume of oil, and the working volume ΔV of the accumulator 14 and the number of times the material door is opened and closed N, the cross-sectional area C of the oil cylinder 22 and the stroke L of the oil cylinder 22 are expressed by equation (2):

[0093]

[0094] Finally, by combining the above equations (1) and (2), we can obtain the prediction calculation formula for the number of times N the material door is opened and closed in step S300:

[0095]

[0096] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A hydraulic system for opening and closing, characterized in that: include: tank; Oil cylinder; the oil cylinder controls the opening and closing of the material port by extending and contracting respectively; An open-closed circuit; the connection ends of the open-closed circuit are respectively connected to the rod chamber and the rodless chamber of the oil cylinder; Accumulator, pump group; the oil inlet of the open-closed circuit is redundantly connected to the accumulator and the pump group, and the oil outlet of the open-closed circuit is connected to the oil tank; the accumulator is suitable for supplying oil or maintaining pressure to the oil cylinder when the pump group is abnormal; Detection module; the detection module is used to monitor the slurry discharge amount of the material outlet and the position of the oil cylinder; and The regulating circuit is connected in parallel with the open-closed circuit, and the regulating circuit is suitable for controlling the oil cylinder to adjust the opening of the material port according to the monitoring result of the detection module.

2. The opening and closing hydraulic system according to claim 1, characterized in that: The open-close circuit includes a first electromagnetic reversing valve, a pair of second hydraulically controlled one-way valves and a pair of one-way throttle valves; The connection port of the first electromagnetic reversing valve is respectively connected to the rodless chamber and the rod chamber of the oil cylinder through a pair of pipelines; the second hydraulically controlled one-way valve and the one-way throttle valve are connected in series on each pipeline, and the control end of the second hydraulically controlled one-way valve is connected to another pipeline; The oil inlet of the first electromagnetic reversing valve is redundantly connected to the accumulator and the pump group respectively, and the oil outlet of the first electromagnetic reversing valve is connected to the oil tank.

3. The opening and closing hydraulic system according to claim 2, characterized in that: The regulating loop comprises: A proportional valve; the oil inlet of the proportional valve is connected in parallel with the oil inlet of the first electromagnetic reversing valve, and the oil outlet of the proportional valve is connected to the oil tank; and A pair of reversing valves; the two connecting ports of the proportional valve are respectively connected to the rod chamber and the rodless chamber of the oil cylinder through the reversing valves connected in series; When the opening of the material port is adjusted, the first electromagnetic reversing valve is cut off, the reversing valve is turned on, and the proportional valve controls the flow rate of the pumped oil according to the opening adjustment amount of the material port.

4. The opening and closing hydraulic system according to claim 3, characterized in that: The reversing valve adopts a hydraulically controlled reversing valve, and the regulating circuit also includes a second electromagnetic reversing valve. The oil inlet and oil outlet of the second electromagnetic reversing valve are respectively connected in parallel with the oil inlet and oil outlet of the first electromagnetic reversing valve, and the connecting port of the second electromagnetic reversing valve is respectively connected to the control ends of the two hydraulically controlled reversing valves.

5. The opening and closing hydraulic system according to claim 3, characterized in that: The pump group includes a first oil pump, a second oil pump and a manual pump; The input ends of the first oil pump, the second oil pump and the manual pump extend to the oil tank, and the output ends of the first oil pump, the second oil pump and the manual pump are connected in parallel to the oil inlet of the first electromagnetic reversing valve; The first oil pump is suitable for supplying oil to the open and closed circuit, or replenishing oil to the accumulator when the pressure of the accumulator is lower than a set value; The manual pump is suitable for replacing the first oil pump to supply oil through manual operation when the first oil pump fails; The rated flow rate of the second oil pump is smaller than the rated flow rate of the first oil pump, and the second oil pump is suitable for supplying oil to the regulating circuit alone when adjusting the opening of the material port.

6. The opening and closing hydraulic system according to any one of claims 1 to 5, characterized in that: The output end of the accumulator is connected in parallel with the output end of the pump group through a first hydraulically controlled one-way valve connected in series, and a first electromagnetic ball valve is installed on the reverse conduction circuit formed by connecting the control end of the first hydraulically controlled one-way valve and the output end of the accumulator; The first electromagnetic ball valve controls the reverse conducting circuit to be cut off when the pump group is working, and then the accumulator is isolated from the open-closed circuit through the first hydraulically controlled one-way valve; When the pump group stops due to an abnormality, the first electromagnetic ball valve controls the reverse conducting circuit to be turned on, and then the accumulator supplies oil to the open-closed circuit.

7. The opening and closing hydraulic system according to claim 6, characterized in that: The accumulator also uses an emergency circuit to quickly close the material port in an emergency; the emergency circuit includes: A first logic valve; the first logic valve is connected between the rod chamber of the oil cylinder and the accumulator; A second logic valve; the second logic valve is connected between the rodless chamber of the cylinder and the oil tank; and Manual ball valve; the control ends of the first logic valve and the second logic valve are connected to the accumulator, and are connected to the oil tank through the manual ball valve; In an emergency, the control oil of the first logic valve and the second logic valve is returned to the oil tank through manual operation of the manual ball valve, thereby opening the main oil circuit of the first logic valve and the second logic valve; at this time, the first electromagnetic ball valve controls the reverse conducting circuit to be cut off.

8. The opening and closing hydraulic system according to claim 7, characterized in that: A pair of second electromagnetic ball valves are connected between the rodless chamber of the oil cylinder and the accumulator, and the second electromagnetic ball valves are connected in series to form a pressure-maintaining branch for maintaining the pressure of the material gate; The control ends of the first logic valve and the second logic valve are both connected to the midpoint of the pressure-maintaining branch, so that when the pressure-maintaining branch is turned on, control oil is delivered to the control ends of the first logic valve and the second logic valve to perform cut-off locking; When the emergency circuit is conducted, the second electromagnetic ball valve close to the accumulator remains blocked.

9. A method for controlling a start-stop hydraulic system according to any one of claims 1 to 8, characterized in that: The steps include: S100: Calculate the slurry discharge amount according to the collected discharge flow rate of the material outlet and the stroke of the oil cylinder; S200: Compare the calculated slurry discharge amount with the set value, convert the difference between the two into an opening signal and send it to the regulating loop, thereby controlling the oil cylinder to extend or retract to adjust the opening of the material port; S300: When the pump group stops working, the duration of the material gate pressure maintenance and the number of times the material gate is opened and closed are predicted based on the performance and structural parameters of the accumulator and the oil cylinder.

10. The control method of the opening and closing hydraulic system according to claim 9, characterized in that: In step S100, the calculation formula of the pulp output M is: Wherein, A represents the opening area of ​​the material port, which is equal to the product of the cylinder stroke L and the opening coefficient a; v(t) represents the relationship between the slurry flow rate v at the material port and the time t; t1 and t2 represent the two interval recording moments of the slurry flow rate at the material port respectively; In step S300, the pressure holding duration T of the material gate is equal to the pressure holding end time t4 minus the pressure holding start time t3. The specific prediction calculation formula is as follows: Among them, ΔV represents the working volume of the accumulator, and S(t) represents the relationship between the cylinder leakage S and time t; In step S300, the prediction calculation formula for the opening and closing times N of the material door is as follows: Among them, V0 represents the volume of the accumulator, p0 represents the charging pressure of the accumulator, p1 represents the minimum pressure of the accumulator, p2 represents the real-time pressure of the accumulator, and n represents the index.

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