Slurry hydraulic control system

Abstract

The invention discloses a slurry hydraulic control system which comprises an oil tank, an oil cylinder, an automatic control loop, a manual control loop and a pump set. The oil cylinder is used for driving a slurry raking head for stirring precipitated slurry to act, the input end of the pump set extends to the oil tank, and the output end of the pump set is connected with the oil cylinder through an automatic control loop and a manual control loop which are connected in parallel; the pump set is suitable for supplying oil to the oil cylinder, and the automatic control loop is suitable for automatically adjusting the oil supply amount flowing to the oil cylinder according to the state of the oil cylinder. The manual control loop is suitable for adjusting the oil supply amount flowing to the oil cylinder according to the autonomously-controlled loop conduction state. The automatic control loop and the manual control loop are not conducted at the same time. The device has the beneficial effects that a hydraulic driving mode is adopted for the slurry raking head, and enough driving force can be provided; and the action state of the pulp raking head can be adjusted manually or automatically according to different conditions of the pulp, so that the working efficiency and the flexibility of the pulp raking head can be effectively improved.

Description

Technical Field

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

[0002] In the manufacturing process of specific industrial products, the slurry system often needs to be left standing or stored in a sedimentation tank or storage tank. When production is required, the stationary or stored slurry needs to be sucked up by a slurry suction pump before entering the next process. Due to the different lengths of standing time of the slurry, the degree of sedimentation or nodules of the slurry may vary; in order to avoid clogging of the slurry suction pump when the slurry is absorbed, the traditional method is to stir the slurry in the sedimentation tank manually or by machine to ensure the uniformity of the slurry. However, the traditional method has the following main problems when stirring the slurry: the efficiency of the manual method is relatively low; the machine stirring generally uses an electric-driven stirring head, which has a relatively small driving force and the stirring head is easy to get stuck; at the same time, it cannot be flexibly adjusted for different mud thicknesses and materials. Summary of the invention

[0003] One of the objects of the present application is to provide a slurry hydraulic control system that can solve at least one of the defects in the above-mentioned background technology.

[0004] In order to achieve at least one of the above-mentioned purposes, the technical solution adopted in the present application is: a slurry hydraulic control system, comprising an oil tank, an oil cylinder, an automatic control circuit, a manual control circuit and a pump group; the oil cylinder is used to drive a rake head for stirring the sedimentation slurry to move, the input end of the pump group extends to the oil tank, and the output end of the pump group is connected to the oil cylinder through the automatic control circuit and the manual control circuit connected in parallel; the pump group is suitable for supplying oil to the oil cylinder, and the automatic control circuit is suitable for automatically adjusting the oil supply to the oil cylinder according to the state of the oil cylinder; the manual control circuit is suitable for adjusting the oil supply to the oil cylinder according to the conduction state of the autonomously controlled circuit; the automatic control circuit and the manual control circuit are not turned on at the same time.

[0005] Preferably, the automatic control circuit includes a proportional pressure reducing valve and a second electro-hydraulic reversing valve; the control pressure of the proportional pressure reducing valve is controlled by the state of the cylinder, and a first branch formed by the series connection of the proportional pressure reducing valve and the second electro-hydraulic reversing valve is connected between the output end of the pump group and the rodless chamber of the cylinder; a second branch is formed between the rod chamber of the cylinder and the pump group through the manual control circuit whose input end is in a cut-off state, and the proportional pressure reducing valve is also connected to the oil tank through a third branch; the pump group supplies oil to the rodless chamber of the cylinder through the first branch to drive the cylinder forward, and at this time a differential circuit is formed between the rodless chamber and the rod chamber of the cylinder; the pump group provides back pressure to the rod chamber of the cylinder through the second branch, and then the cylinder returns oil and contracts through the first branch and the third branch.

[0006] Preferably, the proportional pressure reducing valve adopts a pilot control structure; the automatic control circuit also includes a proportional overflow valve, the input end of the proportional overflow valve is connected to the midpoint of the first branch and / or the inlet of the proportional overflow valve, the output end of the proportional overflow valve is connected to the oil tank, and the input end of the proportional overflow valve is also connected to the control end of the proportional pressure reducing valve; the opening of the proportional overflow valve is controlled according to the comparison between the displacement feedback signal of the oil cylinder or the input pressure signal and the set value, thereby controlling the pilot end pressure of the proportional pressure reducing valve.

[0007] Preferably, the automatic control circuit further comprises a second shuttle valve, wherein the second shuttle valve is connected in parallel to the proportional pressure reducing valve via two input ends, and the output end of the second shuttle valve is connected to the input end of the proportional relief valve.

[0008] Preferably, the manual control circuit includes a third electro-hydraulic reversing valve, a hydraulically controlled one-way valve and a pair of one-way throttle valves; the oil inlet of the third electro-hydraulic reversing valve is connected to the pump group, and the oil return port of the third electro-hydraulic reversing valve is connected to the oil tank and the pump group; the connecting end of the third electro-hydraulic reversing valve is respectively connected to the rodless chamber and the rod chamber of the cylinder through two pipelines installed with the one-way throttle valves, the hydraulically controlled one-way valve is installed on the pipeline connecting the third electro-hydraulic reversing valve to the rodless chamber of the cylinder, and the control end of the hydraulically controlled one-way valve is connected to another pipeline; the third electro-hydraulic reversing valve is in an oil inlet cut-off state when the automatic control circuit is working, at which time the oil return port of the third electro-hydraulic reversing valve cooperates with the cylinder to form the second branch; the energizing state of the third electro-hydraulic reversing valve is controlled by a manual input signal to control the extension and retraction of the cylinder; the one-way throttle valve controls the extension and retraction speed of the cylinder by adjusting the opening.

[0009] Preferably, the rodless chamber and rod chamber of the oil cylinder are respectively connected to the manual control circuit and the automatic control circuit through a balancing circuit; the balancing circuit is used to balance the pressure of the rodless chamber and rod chamber of the oil cylinder, and form a differential circuit when the automatic control circuit is working.

[0010] Preferably, the balancing circuit includes a counterbalancing valve, a one-way valve and a pair of overflow valves; the counterbalancing valve and the pair of overflow valves are connected in parallel to the rodless chamber and the rod chamber of the oil cylinder; the pressure relief directions of the two overflow valves are opposite, the control end of the counterbalancing valve is connected to the rod chamber of the oil cylinder, and the one-way valve is installed in the rod chamber of the oil cylinder; the counterbalancing valve is suitable for forming a differential circuit to drive the oil cylinder to extend when the pressure in the rodless chamber of the oil cylinder is greater than the back pressure; the counterbalancing valve is suitable for forming a differential circuit to drive the oil cylinder to contract when the pressure in the rodless chamber of the oil cylinder is less than the back pressure.

[0011] Preferably, the pump group includes a first oil pump and a second oil pump; the first oil pump is suitable for supplying oil to the manual control circuit and the automatic control circuit, thereby driving the cylinder to extend and retract; the second oil pump is suitable for supplying oil to the second branch formed by the manual control circuit, thereby providing back pressure for the cylinder.

[0012] Preferably, there is a pair of rake heads for stirring the sedimentation slurry, and each rake head is driven and controlled by an independent cylinder; each cylinder corresponds to the manual control circuit, the automatic control circuit and the pump group; the output ends of the two pump groups are connected by a switching circuit, so that when one of the pump groups fails, the other pump group can drive and control the two cylinders at the same time through the switching circuit.

[0013] Preferably, the switching circuit includes a first electro-hydraulic reversing valve and a first shuttle valve; the first electro-hydraulic reversing valve is connected to the output ends of the first oil pumps respectively corresponding to the two pump groups; the first shuttle valve is connected to the first electro-hydraulic reversing valve in parallel through two input ends, and the output end of the first shuttle valve is connected to the control end of the first electro-hydraulic reversing valve; the first shuttle valve is in a cut-off state when the two first oil pumps are working normally, so that the first electro-hydraulic reversing valve is in a natural cut-off state; when one of the first oil pumps fails, the first shuttle valve controls the first electro-hydraulic reversing valve to switch according to the pressure difference at the input end, so that the two oil cylinders are supplied with oil through the first oil pump that is not faulty.

[0014] Compared with the prior art, the beneficial effects of this application are:

[0015] The hydraulic drive mode is adopted for the pulp rake head, which can provide sufficient driving force; and the action state of the pulp rake head can be adjusted manually or automatically according to different conditions of the pulp, thereby effectively improving the working efficiency and flexibility of the pulp rake head. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall control logic of this application.

[0017] Figure 2 This is a schematic diagram of the overall hydraulic structure of this application.

[0018] Figure 3 Schematic diagram of the hydraulic structure of the pump group in this application.

[0019] Figure 4 Schematic diagram of the hydraulic structure of the switching circuit in this application.

[0020] Figure 5 It is a schematic diagram of the hydraulic structure of the automatic control circuit and the manual control circuit in this application.

[0021] Figure 6 Schematic diagram of the hydraulic structure of the balancing circuit in this application.

[0022] In the figure: oil tank 1, pump group 2, plunger pump 21, gear pump 22, switching circuit 3, first electro-hydraulic reversing valve 31, first shuttle valve 32, automatic control circuit 4, proportional pressure reducing valve 41, proportional relief valve 42, second shuttle valve 43, second electro-hydraulic reversing valve 44, manual control circuit 5, third electro-hydraulic reversing valve 51, hydraulically controlled one-way valve 52, one-way throttle valve 53, first relief valve 54, balancing circuit 6, high-pressure stop valve 61, second relief valve 62, one-way valve 63, counter-balancing valve 64, third relief valve 65, oil cylinder 7, accumulator 8. DETAILED DESCRIPTION

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] One of the preferred embodiments of the present application is as follows: Figure 1 and Figure 2As shown, a slurry hydraulic control system includes an oil tank 1, an oil cylinder 7, an automatic control circuit 4, a manual control circuit 5 and a pump group 2. The oil cylinder 7 is used to drive the rake head for stirring the sedimentation slurry to move, and the oil tank 1 is used to provide oil for the movement of the oil cylinder 7 and return oil from the oil cylinder 7. The input end of the pump group 2 extends to the oil tank 1, and the output end of the pump group 2 is connected to the oil cylinder 7 through the automatic control circuit 4 and the manual control circuit 5 connected in parallel.

[0030] When the rake head needs to rake and stir the settled slurry, the pump group 2 can be started and output the pressure oil used to drive the oil cylinder 7 to operate. There are two paths for the pressure oil to flow to the oil cylinder 7, one is to flow to the oil cylinder 7 through the automatic control circuit 4, and the other is to flow to the oil cylinder 7 through the manual control circuit 5. Among them, the automatic control circuit 4 can automatically adjust the oil supply to the oil cylinder 7 according to the state of the oil cylinder 7, thereby controlling the extension direction and extension speed of the oil cylinder 7; the manual control circuit 5 can adjust the oil supply to the oil cylinder 7 according to the conduction state of the self-controlled circuit, thereby controlling the extension direction and extension speed of the oil cylinder 7.

[0031] It should be known that the specific structure and working principle of the raking head are well known to those skilled in the art, so they will not be elaborated in detail here. The working mode of the raking head is similar to the bucket of an excavator. The extension of the oil cylinder 7 can control the distance and angle of the raking head to rotate downward, and the raking head can rake the precipitated slurry; the contraction of the oil cylinder 7 can control the angle and distance of the raking head to rotate upward, and the raking head can reset after completing the raking, so as to prepare for the next raking.

[0032] It is understandable that the precipitated slurry may be in a sludge state or in a hard state of agglomeration, depending on the material of the slurry. For sludge-like precipitation slurry, the load force on the rake head during raking and stirring is small and can be regarded as constant; while for agglomerated precipitation slurry, the load force on the rake head during raking and stirring is uneven and generally large. Traditional methods generally use a constant control loop that adapts to a larger load force when raking and stirring different precipitation slurries, which results in a relatively large amount of energy consumed when raking and stirring sludge-like or agglomerated precipitation slurries.

[0033] In order to adapt to different states of sedimentation slurry, the present embodiment designs an automatic control circuit 4 and a manual control circuit 5 for the control circuit of the oil cylinder 7. The automatic control circuit 4 can automatically adjust the oil supply amount delivered to the oil cylinder 7 by the pump group 2 according to the state information of the oil cylinder 7 under different loads, so as to flexibly control the extension amount and extension speed of the oil cylinder 7, that is, to control the raking power and raking speed of the raking head. The manual control circuit 5 can provide a constant oil supply amount to the oil cylinder 7 in an autonomous control manner, so as to control the oil cylinder 7 to drive the raking head to move with a constant extension amount and extension speed. Specifically, for silty sedimentation slurry or other sedimentation slurry with lower hardness, the present embodiment can control the oil cylinder 7 to drive the raking head to rake and stir through the manual control circuit 5; for sedimentation slurry that may agglomerate, the present embodiment can control the oil cylinder 7 to drive the raking head to rake and stir through the automatic control circuit 4.

[0034] It should be noted that, due to the different control methods of the automatic control loop 4 and the manual control loop 5, the two are not turned on at the same time when in use; that is, the oil cylinder 7 can only operate under the control of one of the control loops. At the same time, the manual control loop 5 does not mean that the entire loop control is manually performed by the staff, but the target raking power and raking speed of the raking head, that is, the working pressure and telescopic speed of the oil cylinder 7 are manually set independently; the telescopic reversing of the oil cylinder 7 is automatically controlled by the program according to the set amount. For the convenience of understanding, the specific implementation methods of the automatic control loop 4 and the manual control loop 5 will be described in detail below.

[0035] In this embodiment, there are many specific structures of the automatic control loop 4 that can realize the above functions. For the sake of easy understanding, one of the structures will be described in detail below. Figure 2 and Figure 5 As shown, the automatic control circuit 4 includes a proportional pressure reducing valve 41 and a second electro-hydraulic reversing valve 44. The control pressure of the proportional pressure reducing valve 41 is controlled by the state of the oil cylinder 7. The first branch formed by the proportional pressure reducing valve 41 and the second electro-hydraulic reversing valve 44 connected in series is connected between the output end of the pump group 2 and the rodless cavity of the oil cylinder 7; at the same time, the second branch is formed between the rod cavity of the oil cylinder 7 and the pump group 2 through the manual control circuit 5 whose input end is in the cut-off state, and the proportional pressure reducing valve 41 is connected to the oil tank 1 through the third branch.

[0036] When the control pressure of the proportional pressure reducing valve 41 needs to be increased according to the state of the oil cylinder 7, it means that it is necessary to supply oil to the rodless chamber of the oil cylinder 7 to drive the oil cylinder 7 to extend forward. Then the second electro-hydraulic reversing valve 44 connects the first branch with the rodless chamber of the oil cylinder 7 under the control of the signal, and then the pump group 2 supplies oil to the rodless chamber of the oil cylinder 7 through the connected first branch to drive the oil cylinder 7 to move forward; at this time, a differential circuit can be formed between the rodless chamber and the rod chamber of the oil cylinder 7, so that the pressure oil in the rod chamber of the oil cylinder 7 can flow back to the rodless chamber, thereby further ensuring the stability of the oil cylinder 7 moving forward.

[0037] When the control pressure of the proportional pressure reducing valve 41 needs to be reduced according to the state of the oil cylinder 7, it means that the oil cylinder 7 needs to be retracted and retreated. Then the pump group 2 can provide back pressure to the rod chamber of the oil cylinder 7 through the second branch, and at the same time, the second electro-hydraulic reversing valve 44 connects the first branch with the rodless chamber of the oil cylinder 7 under the control of the signal, and then the oil in the rodless chamber of the oil cylinder 7 flows back to the oil tank 1 along the connected first branch and the third branch, so that the oil cylinder 7 can retreat.

[0038] It can be understood that, from the above content, the extension and forward movement of the oil cylinder 7 drives the rake head to rake and stir, and the contraction and backward movement of the oil cylinder 7 drives the rake head to reset. Therefore, when the oil cylinder 7 is retreating, the load force on the rake head is relatively small. At this time, it is only necessary to provide a small back pressure to the rod chamber of the oil cylinder 7 to achieve the reset of the rake head, so as to avoid excessive driving force causing the rake head to produce a large reset impact. From the above content, it can be known that the role of the manual control circuit 5 is to provide the oil cylinder 7 with a constant flow to achieve a small load. Therefore, at this time, the manual control circuit 5 can also provide a suitable back pressure for the retreat process of the oil cylinder 7 of the automatic control circuit 4. That is, the automatic control circuit 4 only performs adaptive control of the driving force on the forward direction of the oil cylinder 7.

[0039] It should be known that the specific structures and working principles of the proportional pressure reducing valve 41 and the second electro-hydraulic reversing valve 44 are well known to those skilled in the art, and therefore will not be elaborated in detail here. Figure 5As shown, the proportional pressure reducing valve 41 can adopt a three-way valve, whose inlet is used to connect to the pump group 2, the outlet is used to connect to the inlet of the second electro-hydraulic reversing valve 44, and the oil discharge port is used to connect to the oil tank 1. The second electro-hydraulic reversing valve 44 adopts a two-position four-way valve. For the convenience of understanding, the control end of the second electro-hydraulic reversing valve 44 can be defined as YV2, and the control end of the proportional pressure reducing valve 41 can be defined as YV3; the second electro-hydraulic reversing valve 44 controls the first branch to be in a cut-off state in a natural state, and the proportional pressure reducing valve 41 is in an inlet and outlet conduction state in a natural state. When the oil cylinder 7 needs to move forward, the control end YV2 is energized to conduct the first branch, and then the oil output by the pump group 2 can enter the rodless chamber of the oil cylinder 7; in this process, the control end YV3 can adjust the control pressure according to the degree of control. When the oil cylinder 7 needs to move backward, the control terminal YV2 continues to be energized to conduct the first branch. At this time, the control terminal YV3 can control the outlet of the proportional pressure reducing valve 41 to be connected to the oil discharge port to conduct the third branch. Then, the oil in the rodless chamber of the oil cylinder 7 can flow back to the oil tank 1 along the first branch and the third branch. Figure 5 It can be represented by T, and the rodless chamber and the rod chamber of the cylinder 7 are represented by A and B respectively.

[0040] In this embodiment, the proportional pressure reducing valve 41 is the key to the automatic control circuit 4 to realize the adaptive control of the driving force of the oil cylinder 7, that is, the opening of the proportional pressure reducing valve 41 is adaptively controlled by the state of the oil cylinder 7, thereby realizing the adaptive adjustment of the control pressure of the proportional pressure reducing valve 41. There are many ways to perform adaptive control of the opening of the proportional pressure reducing valve 41, such as electromagnetic control or hydraulic pilot control; in order to ensure stable control, in this embodiment, the hydraulic pilot control structure is preferably used for the proportional pressure reducing valve 41. Figure 5 As shown, the automatic control circuit 4 also includes a proportional overflow valve 42, the input end of the proportional overflow valve 42 is connected to the midpoint of the first branch and / or the inlet of the proportional pressure reducing valve 41, the output end of the proportional overflow valve 42 is connected to the oil tank 1, and the input end of the proportional overflow valve 42 is also connected to the control end of the proportional pressure reducing valve 41.

[0041] It can be understood that the opening of the proportional relief valve 42 is controlled by the state of the cylinder 7; the state of the cylinder 7 includes the displacement state and the pressure state, etc., and the opening of the proportional relief valve 42 can be controlled according to the comparison between the displacement feedback signal of the cylinder 7 or the input pressure signal and the set value, thereby controlling the pilot end pressure of the proportional pressure reducing valve 41.

[0042] Specifically, when the oil at the input end of the proportional relief valve 42 flows back to the oil tank 1 through the proportional relief valve 42, the pressure at the input end of the proportional relief valve 42 is greater than the pressure at the output end due to the opening limit of the proportional relief valve 42, so that part of the oil flows to the control end of the proportional pressure reducing valve 41 through the pipeline. The control end of the proportional relief valve 42 can be defined as YV4; when the control pressure of the proportional pressure reducing valve 41 needs to be increased, that is, the opening of the proportional pressure reducing valve 41 needs to be reduced, and the oil cylinder 7 needs to move forward at this time; then the input current of the control end YV4 controls the opening of the proportional relief valve 42 to decrease according to the state of the oil cylinder 7, so that the oil flowing to the control end of the proportional pressure reducing valve 41 increases, and then drives the valve core to move in the direction of decreasing the opening. On the contrary, the opening of the proportional relief valve 42 increases to control the increase of the opening of the proportional pressure reducing valve 41. The proportional relief valve 42 adopts an electro-hydraulic control method, and then adjusts the input current of the control end according to the detection signal of the sensor installed on the oil cylinder 7 to adjust the opening.

[0043] It should be noted that in order to ensure that the opening of the proportional pressure reducing valve 41 can be stably controlled, it is necessary to ensure that the pressure at the input end of the proportional relief valve 42 must be greater than the minimum control pressure at the control end of the proportional pressure reducing valve 41. However, during the operation of the first branch, the midpoint pressure may be too low, which may cause the opening control of the proportional pressure reducing valve 41 to fail. Therefore, the input end of the proportional relief valve 42 can be connected to the inlet and outlet positions of the proportional pressure reducing valve 41 respectively. When the pressure is too low at the outlet position of the proportional pressure reducing valve 41, that is, the midpoint position of the first branch, the input end pressure of the proportional relief valve 42 can come from the inlet position of the proportional pressure reducing valve 41; on the contrary, when the oil cylinder 7 is retreating, the inlet pressure of the proportional pressure reducing valve 41 is zero, and at this time, the input end pressure of the proportional relief valve 42 can come from the outlet of the proportional pressure reducing valve 41, that is, the midpoint of the first branch.

[0044] In this embodiment, Figure 5 As shown, in order to realize the adaptive selection of the pressure at the input end of the proportional relief valve 42, the automatic control circuit 4 also includes a second shuttle valve 43, which is connected in parallel to the inlet and outlet of the proportional pressure reducing valve 41 through two input ends, and the output end of the second shuttle valve 43 is connected to the input end of the proportional relief valve 42. The function of the second shuttle valve 43 is to output the maximum pressure of the two input ends. The specific structure and working principle of the second shuttle valve 43 and the proportional relief valve 42 are well-known technologies to those skilled in the art, so they will not be elaborated in detail here.

[0045] In this embodiment, there are many specific structures of the manual control circuit 5 that can realize the above functions. For the sake of easy understanding, the following will be described in detail using one of the structures. Figure 1 , Figure 2 and Figure 5As shown, the manual control circuit 5 includes a third electro-hydraulic reversing valve 51, a hydraulically controlled one-way valve 52, and a pair of one-way throttle valves 53. The oil inlet of the third electro-hydraulic reversing valve 51 is connected to the pump group 2, and the oil return port of the third electro-hydraulic reversing valve 51 is connected to the oil tank 1 and the pump group 2; the connecting end of the third electro-hydraulic reversing valve 51 is respectively connected to the rodless chamber and the rod chamber of the oil cylinder 7 through two pipelines equipped with one-way throttle valves 53; the hydraulically controlled one-way valve 52 is installed in the pipeline connecting the third electro-hydraulic reversing valve 51 to the rodless chamber of the oil cylinder 7, and the control end of the hydraulically controlled one-way valve 52 is connected to another pipeline.

[0046] When the automatic control circuit 4 is working, the third electro-hydraulic reversing valve 51 shall not be energized, and the oil inlet of the third electro-hydraulic reversing valve 51 is in a cut-off state; and the oil return port of the third electro-hydraulic reversing valve 51 can cooperate with the rod chamber of the oil cylinder 7 to form a second branch, so that the pressure output by the pump group 2 can be transmitted to the rod chamber of the oil cylinder 7 through the third electro-hydraulic reversing valve 51 and the corresponding pipeline to generate back pressure to drive the oil cylinder 7 to retreat.

[0047] When it is necessary to drive the cylinder 7 to extend and move forward through the manual control circuit 5, the third electro-hydraulic reversing valve 51 can connect the rodless chamber of the cylinder 7 with the output end of the pump group 2 by energizing the control end, so that the pressure oil output by the pump group 2 enters the rodless chamber of the cylinder 7; at the same time, the rod chamber of the cylinder 7 is connected to the oil tank 1, so that the oil in the rod chamber of the cylinder 7 can flow back to the oil tank 1.

[0048] When it is necessary to drive the cylinder 7 to retract and retreat through the manual control circuit 5, the third electro-hydraulic reversing valve 51 can connect the rod chamber of the cylinder 7 with the output end of the pump group 2 by obtaining power at the control end, so that the pressure oil output by the pump group 2 enters the rod chamber of the cylinder 7. At the same time, the pressure oil can also drive the hydraulically controlled one-way valve 52 connected to the rodless chamber of the cylinder 7 to conduct reverse conduction, and then the rodless chamber of the cylinder 7 can be connected to the oil tank 1, so that the oil in the rodless chamber of the cylinder 7 can flow back to the oil tank 1.

[0049] It should be known that the specific structures and working principles of the third electro-hydraulic reversing valve 51, the one-way throttle valve 53 and the hydraulic one-way valve 52 are well known to those skilled in the art. The one-way throttle valve 53 can control the extension and retraction speed of the oil cylinder 7 by adjusting the opening; the hydraulic one-way valve 52 can form a hydraulic lock to ensure that the oil cylinder 7 can maintain a stable position under the load. There are many specific types of the third electro-hydraulic reversing valve 51, such as Figure 5As shown, the third electro-hydraulic reversing valve 51 adopts a Y-type three-position four-way reversing valve; its two control terminals are defined as YV5 and YV6 respectively. When the oil cylinder 7 needs to be moved forward, the control terminal YV5 is energized so that the output terminal of the pump group 2 is connected to the rodless cavity of the oil cylinder 7, and the oil tank 1 is connected to the rod cavity of the oil cylinder 7; when the oil cylinder 7 needs to be moved backward, the control terminal YV6 is energized so that the output terminal of the pump group 2 is connected to the rod cavity of the oil cylinder 7, and the oil tank 1 is connected to the rodless cavity of the oil cylinder 7.

[0050] It is understandable that, in order to ensure the safety of the manual control circuit 5, the manual control circuit 5 further includes a first overflow valve 54, which is connected in parallel to the oil inlet and the oil return port of the third electro-hydraulic reversing valve 51. The first overflow valve 54 can return the pressure oil output by the pump group 2 to the oil tank 1 when a conduction failure occurs in the manual control circuit 5 to protect the safety of the manual control circuit 5. The specific structure and working principle of the first overflow valve 54 are well-known technologies to those skilled in the art, so they will not be elaborated in detail here.

[0051] In this embodiment, Figure 1 and Figure 2 As shown, the rodless chamber and the rod chamber of the oil cylinder 7 are connected to the manual control circuit 5 and the automatic control circuit 4 respectively through the balancing circuit 6. The balancing circuit 6 is used to balance the pressure of the rodless chamber and the rod chamber of the oil cylinder 7, and form a differential circuit when the automatic control circuit 4 is working; thereby ensuring the safety of the automatic control circuit 4 and the manual control circuit 5 in supplying oil to the oil cylinder 7, preventing the oil cylinder 7 from being overloaded; and at the same time, it can also ensure the working stability of the oil cylinder 7 when the oil cylinder 7 encounters a sudden load.

[0052] Specifically, there are many specific structures of the balancing circuit 6 that can achieve the above functions. For the sake of easy understanding, one of the structures will be described in detail below. Figure 6 As shown, the balancing circuit 6 includes a counter-balancing valve 64, a one-way valve 63 and a pair of relief valves. The counter-balancing valve 64 and the pair of relief valves are connected in parallel to the rodless chamber and the rod chamber of the oil cylinder 7; the pressure relief directions of the two relief valves are opposite, the control end of the counter-balancing valve 64 is connected to the rod chamber of the oil cylinder 7, and the one-way valve 63 is installed in the rod chamber of the oil cylinder 7. The counter-balancing valve 64 can form a differential circuit to drive the oil cylinder 7 to extend when the pressure of the rodless chamber of the oil cylinder 7 is greater than the back pressure; the counter-balancing valve 64 can form a differential circuit to drive the oil cylinder 7 to retract when the pressure of the rodless chamber of the oil cylinder 7 is less than the back pressure.

[0053] It can be understood that the two relief valves are the second relief valve 62 and the third relief valve 65; the pressure relief direction of the second relief valve 62 is toward the pipeline connected to the rod chamber of the oil cylinder 7, and the pressure relief direction of the third relief valve 65 is toward the pipeline connected to the rodless chamber of the oil cylinder 7. The second relief valve 62 and the third relief valve 65 can cooperate to form a safety valve group, thereby preventing the oil cylinder 7 from being overloaded to ensure the safe operation of the system. That is, when the oil cylinder 7 encounters an overload or other fault during the forward movement, the pressure oil delivered by the pump group 2 can flow back to the oil tank 1 from the second relief valve 62; similarly, when the oil cylinder 7 encounters an overload or other fault during the backward movement, the pressure oil delivered by the pump group 2 can flow back to the oil tank 1 from the third relief valve 65.

[0054] It can also be understood that the counter-valve 64 and the one-way valve 63 can cooperate to form a differential circuit to balance the back pressure generated by the oil cylinder 7 and the load on the oil cylinder 7, thereby ensuring that the oil cylinder 7 reacts quickly and operates smoothly. That is, when the load increases (the pressure of the rodless chamber of the oil cylinder 7 increases), the back pressure decreases, and the counter-valve 64 can be opened to form a differential circuit to ensure that the oil cylinder 7 can move forward; conversely, when the load decreases (the pressure of the rodless chamber of the oil cylinder 7 decreases), the back pressure increases, and the oil cylinder 7 retreats through the differential circuit and stops at a balanced position.

[0055] It should be noted that the specific structures and working principles of the overflow valve, the counterbalance valve 64 and the one-way valve 63 are well known to those skilled in the art, and therefore will not be elaborated in detail here. Figure 6 As shown, the balancing circuit 6 also includes a pair of high-pressure stop valves 61, which are installed at one end of the two pipelines of the balancing circuit 6 away from the oil cylinder 7, and the high-pressure stop valve 61 can cut off or adjust the pipeline. The specific structure and working principle of the high-pressure stop valve 61 are well-known technologies to those skilled in the art, so they will not be elaborated in detail here.

[0056] In this embodiment, Figure 3 As shown, the pump group 2 includes a first oil pump and a second oil pump; the first oil pump can supply oil to the manual control circuit 5 and the automatic control circuit 4, thereby driving the oil cylinder 7 to extend and retract; the second oil pump can supply oil to the second branch formed by the manual control circuit 5, thereby providing back pressure for the oil cylinder 7. Specifically, Figure 5 As shown, the output end of the first oil pump is connected to the oil inlet of the third electro-hydraulic reversing valve 51 in the manual control circuit 5 and the inlet of the proportional pressure reducing valve 41 in the automatic control circuit 4; the output end of the second oil pump is connected to the oil discharge port of the third electro-hydraulic reversing valve 51 in the manual control circuit 5.

[0057] It is understandable that, from the above content, the pump group 2 not only needs to normally drive the oil cylinder 7 to extend and retract, but also needs to provide back pressure for the oil cylinder 7; if both oil supply methods are supplied by the same oil pump, then a corresponding switching structure must be designed, which will make the system structure complex and increase the failure rate. Therefore, two oil pumps are set in this embodiment, the first oil pump is used to supply oil for the normal drive of the oil cylinder 7, and the second oil pump is only used to provide back pressure for the oil cylinder 7, so that different oil pumps only need to be opened and closed according to different work requirements.

[0058] It should be known that the output pressure requirement of the first oil pump is relatively large, so the first oil pump can preferably use a plunger pump 21; the output pressure requirement of the second oil pump is relatively small, so the second oil pump can preferably use a gear pump 22. The specific structure and working principle of the plunger pump 21 and the gear pump 22 are well-known technologies for those skilled in the art, so they will not be elaborated in detail here. For ease of understanding, Figure 3 As shown, the output pressure of the plunger pump 21 is represented by P1, and the output pressure of the gear pump 22 is represented by P2.

[0059] It should be known to those skilled in the art that the stirring of the sedimentation slurry can be a single-rake slurry head structure, that is, like the single bucket structure of an excavator; of course, the stirring of the sedimentation slurry can also be a double-rake slurry head structure, where the two rake slurry heads are arranged opposite to each other and the raking stirring of the sedimentation slurry is achieved by simultaneously approaching and biting. The movements of the two rake slurry heads are driven and controlled by independent oil cylinders 7, that is, Figure 1 As shown, each rake head corresponds to an independent oil cylinder 7, a balance circuit 6, a manual control circuit 5, an automatic control circuit 4 and a pump group 2. For the two rake heads, the actions of the two are synchronized. If one of the rake heads does not move, the entire slurry mixing process will not be able to proceed. Therefore, the two pump groups 2 corresponding to the two rake heads are connected through a switching circuit 3, so that when one of the pump groups 2 fails, the other pump group 2 drives and controls the two oil cylinders 7 at the same time through the switching circuit 3, thereby ensuring the stable operation of the entire hydraulic control system.

[0060] In this embodiment, there are multiple specific structures of the switching circuit 3 that can realize the above functions. For the sake of easy understanding, one of the structures will be described in detail below. Figure 4 As shown, the switching circuit 3 includes a first electro-hydraulic reversing valve 31 and a first shuttle valve 32; the first electro-hydraulic reversing valve 31 is connected to the output ends of the first oil pumps corresponding to the two pump groups 2 respectively; the first shuttle valve 32 is connected in parallel to the first electro-hydraulic reversing valve 31 through two input ends, and the output end of the first shuttle valve 32 is connected to the control end of the first electro-hydraulic reversing valve 31.

[0061] When both pump groups 2 are working normally, the output pressures of the first oil pumps corresponding to the two should be consistent, and the first shuttle valve 32 will be in a cut-off state at this time, so that the first electro-hydraulic reversing valve 31 is in a natural cut-off state. When one of the first oil pumps fails, the pressure at the input end of the first oil pump corresponding to the failure of the first shuttle valve 32 is reduced to zero, and the first shuttle valve 32 can transmit the pressure of the other input end to the control end of the first electro-hydraulic reversing valve 31 to drive the first electro-hydraulic reversing valve 31 to switch and conduct, that is, the first shuttle valve 32 controls the first electro-hydraulic reversing valve 31 to switch according to the pressure difference at the input end, so that both oil cylinders 7 are supplied with oil through the first oil pump that is not faulty.

[0062] It should be known that the specific structures and working principles of the first shuttle valve 32 and the first electro-hydraulic reversing valve 31 are well-known technologies to those skilled in the art, so they will not be elaborated in detail here. The function of the first shuttle valve 32 is to cut off the first electro-hydraulic reversing valve 31 when the pressure at the input end is balanced, and to drive the first electro-hydraulic reversing valve 31 to change direction when there is a pressure difference at the input end. The first electro-hydraulic reversing valve 31 preferably adopts a two-position four-way valve, and its control end can be defined as YV1. The control end YV1 controls the valve core to move according to the output pressure of the first shuttle valve 32 to achieve reversal.

[0063] It should be noted that the switching circuit 3 can only provide the output pressure of the first oil pump to the two cylinders 7 at the same time. If both the first oil pump and the second oil pump fail, the switching circuit 3 can only be used when the manual control circuit 5 is working normally; the working pressure of the manual control circuit 5 is relatively low, and the single first oil pump can meet the pressure requirements of the two manual control circuits 5.

[0064] It is understandable that when the first oil pump fails, the switching process of the switching circuit 3 may be delayed; in order to further ensure the working safety of the hydraulic control system, such as Figure 1 , Figure 2 and Figure 5 As shown, an accumulator 8 can also be connected in parallel at the connection position between each first oil pump and the manual control circuit 5 and the automatic control circuit 4, so that when the first oil pump of the pump group 2 fails, the accumulator 8 can quickly replenish oil to ensure the stability of the oil circuit; as the output pressure of the accumulator 8 on the faulty side gradually decreases, the switching circuit 3 will gradually open, thereby ensuring the switching stability of the switching circuit 3.

[0065] 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 slurry hydraulic control system, characterized in that: Including oil tank, oil cylinder, automatic control circuit, manual control circuit and pump set; The oil cylinder is used to drive the rake head for stirring the sedimentation slurry to move; The input end of the pump group extends to the oil tank, and the output end of the pump group is connected to the oil cylinder through the automatic control circuit and the manual control circuit connected in parallel; The pump group is suitable for supplying oil to the cylinder, and the automatic control circuit is suitable for automatically adjusting the amount of oil supplied to the cylinder according to the state of the cylinder; the manual control circuit is suitable for adjusting the amount of oil supplied to the cylinder according to the conduction state of the autonomously controlled circuit; the automatic control circuit and the manual control circuit are not turned on at the same time.

2. The slurry hydraulic control system according to claim 1, characterized in that: The automatic control circuit includes a proportional pressure reducing valve and a second electro-hydraulic reversing valve; The control pressure of the proportional pressure reducing valve is controlled by the state of the oil cylinder. The first branch formed by the series connection of the proportional pressure reducing valve and the second electro-hydraulic reversing valve is connected between the output end of the pump group and the rodless chamber of the oil cylinder. The second branch is formed between the rod chamber of the oil cylinder and the pump group through the manual control circuit whose input end is in a cut-off state. The proportional pressure reducing valve is also connected to the oil tank through a third branch. The pump group supplies oil to the rodless chamber of the cylinder through the first branch to drive the cylinder forward. At this time, a differential circuit is formed between the rodless chamber and the rod chamber of the cylinder; the pump group provides back pressure to the rod chamber of the cylinder through the second branch, and then the cylinder returns oil and contracts through the first branch and the third branch.

3. The slurry hydraulic control system according to claim 2, characterized in that: The proportional pressure reducing valve adopts a pilot control structure; The automatic control circuit further comprises a proportional relief valve, the input end of the proportional relief valve is connected to the midpoint of the first branch and / or the inlet of the proportional relief valve, the output end of the proportional relief valve is connected to the oil tank, and the input end of the proportional relief valve is also connected to the control end of the proportional pressure reducing valve; The opening of the proportional relief valve is controlled according to the comparison between the displacement feedback signal of the oil cylinder or the input pressure signal and the set value, thereby controlling the pilot end pressure of the proportional pressure reducing valve.

4. The slurry hydraulic control system according to claim 3, characterized in that: The automatic control circuit further comprises a second shuttle valve, which is connected in parallel to the proportional pressure reducing valve via two input ends, and the output end of the second shuttle valve is connected to the input end of the proportional relief valve.

5. The slurry hydraulic control system according to claim 2, characterized in that: The manual control circuit includes a third electro-hydraulic reversing valve, a hydraulically controlled one-way valve and a pair of one-way throttle valves; The oil inlet of the third electro-hydraulic reversing valve is connected to the pump group, and the oil return port of the third electro-hydraulic reversing valve is connected to the oil tank and the pump group; the connecting end of the third electro-hydraulic reversing valve is respectively connected to the rodless chamber and the rod chamber of the oil cylinder through two pipelines installed with the one-way throttle valve, the hydraulically controlled one-way valve is installed on the pipeline connecting the third electro-hydraulic reversing valve to the rodless chamber of the oil cylinder, and the control end of the hydraulically controlled one-way valve is connected to another pipeline; The third electro-hydraulic reversing valve is in an oil inlet cut-off state when the automatic control circuit is working. At this time, the oil return port of the third electro-hydraulic reversing valve cooperates with the oil cylinder to form the second branch; Controlling the energized state of the third electro-hydraulic reversing valve by manually inputting a signal to control the extension and retraction of the oil cylinder; The one-way throttle valve controls the extension and retraction speed of the oil cylinder by adjusting the opening degree.

6. The slurry hydraulic control system according to claim 5, characterized in that: The rodless chamber and rod chamber of the oil cylinder are connected to the manual control circuit and the automatic control circuit respectively through a balancing circuit; the balancing circuit is used to balance the pressure of the rodless chamber and rod chamber of the oil cylinder and form a differential circuit when the automatic control circuit is working.

7. The slurry hydraulic control system according to claim 6, characterized in that: The balancing circuit includes a counter-balancing valve, a one-way valve and a pair of relief valves; The counterbalance valve and the pair of relief valves are connected in parallel to the rodless chamber and the rod chamber of the oil cylinder; the pressure relief directions of the two relief valves are opposite, the control end of the counterbalance valve is connected to the rod chamber of the oil cylinder, and the one-way valve is installed in the rod chamber of the oil cylinder; The counterbalance valve is suitable for forming a differential circuit to drive the cylinder to extend when the rodless chamber pressure of the cylinder is greater than the back pressure; the counterbalance valve is suitable for forming a differential circuit to drive the cylinder to retract when the rodless chamber pressure of the cylinder is less than the back pressure.

8. The slurry hydraulic control system according to any one of claims 2 to 7, characterized in that: The pump group includes a first oil pump and a second oil pump; the first oil pump is suitable for supplying oil to the manual control circuit and the automatic control circuit, thereby driving the cylinder to extend and retract; the second oil pump is suitable for supplying oil to the second branch formed by the manual control circuit, thereby providing back pressure for the cylinder.

9. The slurry hydraulic control system according to claim 8, characterized in that: There is a pair of rake heads for stirring the sedimentation slurry, and each rake head is driven and controlled by an independent oil cylinder; Each of the oil cylinders corresponds to the manual control circuit, the automatic control circuit and the pump group; The output ends of the two pump groups are connected via a switching circuit, so that when one of the pump groups fails, the other pump group can drive and control the two oil cylinders simultaneously via the switching circuit.

10. The slurry hydraulic control system according to claim 9, characterized in that: The switching circuit includes a first electro-hydraulic reversing valve and a first shuttle valve; The first electro-hydraulic reversing valve is connected to the output ends of the first oil pumps respectively corresponding to the two pump groups; The first shuttle valve is connected in parallel to the first electro-hydraulic reversing valve via two input ends, and the output end of the first shuttle valve is connected to the control end of the first electro-hydraulic reversing valve; The first shuttle valve is in a cut-off state when the two first oil pumps work normally, so that the first electro-hydraulic reversing valve is in a natural cut-off state; When one of the first oil pumps fails, the first shuttle valve controls the first electro-hydraulic reversing valve to switch direction according to the pressure difference at the input end, so that both of the oil cylinders are supplied with oil through the first oil pump that is not faulty.

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