Pumping system

Abstract

This application relates to a pumping system, which includes a valve body, a first switching valve group and a second switching valve group. The valve body is provided with a main oil inlet passage capable of connecting the first switching valve group and an oil pump, and a main oil return passage capable of connecting the first switching valve group and an external oil tank. Under high-pressure pumping conditions: the second switching valve group is in the third connection position c, and under low-pressure pumping conditions: the second switching valve group is in the fourth connection position d. The pumping system provided by this application solves the problem that both electromagnetic switching valve groups of the existing pumping system need to be frequently switched, resulting in a reduced service life, thus causing failures of the pumping system and further increasing the maintenance cost of the pumping system.

Description

Technical Field

[0001] This application relates to the technical field of hydraulic control systems for construction machinery, and particularly to a pumping system. Background Art

[0002] In the fields of construction machinery and building machinery, many devices such as concrete pump trucks, excavators, loaders, and compact excavators need to use hydraulic cylinders to bear loads or perform actions, and the actions of hydraulic cylinders are generally controlled by control valves. For example, when a concrete pump truck is working, the pumping cylinder and the swing cylinder need to act alternately. The alternate actions between the pumping cylinders and between the pumping cylinder and the swing cylinder need to be controlled by a pumping system, that is, the pumping system controls the mortar pump to supply oil to the pumping cylinder or the swing cylinder to achieve the alternate actions between the pumping cylinders or between the pumping cylinder and the swing cylinder.

[0003] The pumping system of the prior art has a structure including a base, on which there are a main inlet port communicating with a mortar pump, a return port communicating with an oil tank, and an outlet port and a return port communicating with the two oil ports of two pumping cylinders. A first electromagnetic switching valve group and a second electromagnetic switching valve group are connected to the top of the base. The first electromagnetic switching valve group and the second electromagnetic switching valve group respectively control the main inlet port to supply oil to the outlet port or the return port of the two pumping cylinders. Moreover, in order to realize the alternate telescopic operation of the two pumping cylinders, both the first electromagnetic switching valve group and the second electromagnetic switching valve group need to frequently switch their connection positions. Thus, the service lives of both the first electromagnetic switching valve group and the second electromagnetic switching valve group will be greatly reduced, resulting in a sharp increase in the maintenance cost of the pumping system. Summary of the Invention

[0004] Based on this, it is necessary to provide a pumping system to solve the problem that the service lives of the two electromagnetic switching valve groups of the existing pumping system are reduced due to frequent switching, thereby increasing the maintenance cost of the pumping system.

[0005] The pumping system provided in this application includes a valve body, a first switching valve group, and a second switching valve group. The valve body is provided with a main inlet passage capable of connecting the first switching valve group and an oil pump, and a main return passage capable of connecting the first switching valve group and an external oil tank;

[0006] Under high-pressure pumping conditions: When the first switching valve group is in the first communication position a and the second switching valve group is in the third communication position c, the main oil inlet passage is sequentially connected to the second rodless cavity of the second oil cylinder through the first switching valve group and the second switching valve group; the second rod chamber of the second oil cylinder is connected to the first rod chamber of the first oil cylinder; the first rodless cavity of the first oil cylinder is sequentially connected to the main oil return passage through the second switching valve group and the first switching valve group; When the first switching valve group is in the second communication position b and the second switching valve group is in the third communication position c, the main oil inlet passage is sequentially connected to the first rodless cavity of the first oil cylinder through the first switching valve group and the second switching valve group; the first rod chamber of the first oil cylinder is connected to the second rod chamber of the second oil cylinder; the second rodless cavity of the second oil cylinder is sequentially connected to the main oil return passage through the second switching valve group and the first switching valve group;

[0007] Under low-pressure pumping conditions: When the first switching valve group is in the first communication position a and the second switching valve group is in the fourth communication position d, the main oil inlet passage is sequentially connected to the second rod chamber of the second oil cylinder through the first switching valve group and the second switching valve group; the second rodless cavity of the second oil cylinder is connected to the first rodless cavity of the first oil cylinder; the first rod chamber of the first oil cylinder is sequentially connected to the main oil return passage through the second switching valve group and the first switching valve group; When the first switching valve group is in the second communication position b and the second switching valve group is in the fourth communication position d, the main oil inlet passage is sequentially connected to the first rod chamber of the first oil cylinder through the first switching valve group and the second switching valve group; the first rodless cavity of the first oil cylinder is connected to the second rodless cavity of the second oil cylinder; the second rod chamber of the second oil cylinder is sequentially connected to the main oil return passage through the second switching valve group and the first switching valve group.

[0008] In one embodiment, the first switching valve group includes a first valve seat and a first valve core. The first valve seat is provided with a first valve cavity, and the first valve core is movably arranged in the first valve cavity to control the first switching valve group to be in the first communication position a or the second communication position b; the second switching valve group includes a second valve seat and a second valve core. The second valve seat is provided with a second valve cavity, and the second valve core is movably arranged in the second valve cavity to control the second switching valve group to be in the third communication position c or the fourth communication position d. Moreover, the fitting clearance between the second valve core and the second valve seat is smaller than the fitting clearance between the first valve core and the first valve seat. It can be understood that the fitting clearance between the second valve core and the second valve seat is smaller. With such a setting, the leakage of pressure oil is effectively blocked, thereby avoiding the oil leakage during the work of the first piston or the second piston. The fitting clearance between the first valve core and the first valve seat is larger, which is beneficial to improving the switching flexibility of the first switching valve group and the working efficiency of the pumping system.

[0009] In one embodiment, the first switching valve group includes a first communication valve and two first solenoid valves. The two first solenoid valves are respectively connected to both ends of the first communication valve to drive the first communication valve to be in a first communication position a, a second communication position b, or a first intermediate disconnection position e, where the first intermediate disconnection position e is provided between the first communication position a and the second communication position b. The second switching valve group includes a second communication valve and two second solenoid valves. The two second solenoid valves are respectively connected to both ends of the second communication valve to drive the second communication valve to be in a third communication position c, a fourth communication position d, or a second intermediate disconnection position f, where the second intermediate disconnection position f is provided between the third communication position c and the fourth communication position d.

[0010] In one embodiment, the second switching valve group includes a second communication valve and a second solenoid valve. The second solenoid valve is connected to one end of the second communication valve to drive the second communication valve to be in the third communication position c or the fourth communication position d. It can be understood that such a setting is beneficial to simplifying the structure of the pumping system and reducing the manufacturing cost of the pumping system.

[0011] In one embodiment, the valve body is further provided with a first oil passage capable of communicating the second switching valve group and the first rod chamber, a second oil passage capable of communicating the second switching valve group and the first rodless chamber, a third oil passage capable of communicating the second switching valve group and the second rod chamber, and a fourth oil passage capable of communicating the second switching valve group and the second rodless chamber; a first passage and a second passage are provided between the first switching valve group and the second switching valve group.

[0012] Under the high-pressure pumping condition: when the first switching valve group is in the first communication position a and the second switching valve group is in the third communication position c, the main oil inlet passage is sequentially communicated with the first switching valve group, the second passage, the second switching valve group, the fourth oil passage, and the second rodless chamber of the second oil cylinder; the second rod chamber of the second oil cylinder is communicated with the first rod chamber of the first oil cylinder; the first rodless chamber of the first oil cylinder is sequentially communicated with the second oil passage, the second switching valve group, the first passage, the first switching valve group, and the main oil return passage; when the first switching valve group is in the second communication position b and the second switching valve group is in the third communication position c, the main oil inlet passage is sequentially communicated with the first switching valve group, the first passage, the second switching valve group, the second oil passage, and the first rodless chamber of the first oil cylinder; the first rod chamber of the first oil cylinder is communicated with the second rod chamber of the second oil cylinder; the second rodless chamber of the second oil cylinder is sequentially communicated with the fourth oil passage, the second switching valve group, the second passage, the first switching valve group, and the main oil return passage.

[0013] Under low-pressure pumping conditions: When the first switching valve group is in the first communication position a and the second switching valve group is in the fourth communication position d, the main oil inlet passage is sequentially connected to the first switching valve group, the second passage, the second switching valve group, the third oil passage, and the second rodless cavity of the second oil cylinder; the second rodless cavity of the second oil cylinder is connected to the first rodless cavity of the first oil cylinder; the first rodless cavity of the first oil cylinder is sequentially connected to the first oil passage, the second switching valve group, the first passage, the first switching valve group, and the main oil return passage; when the first switching valve group is in the second communication position b and the second switching valve group is in the fourth communication position d, the main oil inlet passage is sequentially connected to the first switching valve group, the first passage, the second switching valve group, the first oil passage, and the first rodless cavity of the first oil cylinder; the first rodless cavity of the first oil cylinder is connected to the second rodless cavity of the second oil cylinder; the second rodless cavity of the second oil cylinder is sequentially connected to the third oil passage, the second switching valve group, the second passage, the first switching valve group, and the main oil return passage.

[0014] In one embodiment, an intercommunicating oil passage is provided in the second switching valve group; when the first switching valve group is in the first communication position a and the second switching valve group is in the third communication position c, the second rodless cavity of the second oil cylinder is sequentially connected to the third oil passage, the intercommunicating oil passage, the first oil passage, and the first rodless cavity of the first oil cylinder; when the first switching valve group is in the second communication position b and the second switching valve group is in the third communication position c, the first rodless cavity of the first oil cylinder is sequentially connected to the first oil passage, the intercommunicating oil passage, the third oil passage, and the second rodless cavity of the second oil cylinder. It can be understood that with such a setting, it is beneficial to simplify the structure of the pumping system.

[0015] In one embodiment, the pumping system further includes a locking valve group; when the first switching valve group is in the first communication position a and the second switching valve group is in the fourth communication position d, the locking valve group is opened, and the second rodless cavity of the second oil cylinder is connected to the first rodless cavity of the first oil cylinder through the locking valve group; when the first switching valve group is in the second communication position b and the second switching valve group is in the fourth communication position d, the locking valve group is opened, and the first rodless cavity of the first oil cylinder is connected to the second rodless cavity of the second oil cylinder through the locking valve group; when the first switching valve group is in the first communication position a and the second switching valve group is in the third communication position c, the locking valve group is closed, and the second rodless cavity of the second oil cylinder is disconnected from the first rodless cavity of the first oil cylinder; when the first switching valve group is in the second communication position b and the second switching valve group is in the third communication position c, the locking valve group is closed, and the first rodless cavity of the first oil cylinder is disconnected from the second rodless cavity of the second oil cylinder.

[0016] In one embodiment, the locking valve group includes a first locking valve, a second locking valve, and a third solenoid valve, and the third solenoid valve can drive the first locking valve and the second locking valve to open or close.

[0017] In one embodiment, the first locking valve and the second locking valve are arranged in parallel between the first rodless cavity and the second rodless cavity.

[0018] In one embodiment, the pumping system further includes a check valve, and the main oil inlet passage is connected to the first switching valve group through the check valve. It can be understood that such an arrangement is beneficial to preventing the pressure oil in the first switching valve group from flowing back through the main oil inlet passage.

[0019] Compared with the prior art, in the pumping system provided by the present application, in the high-pressure pumping condition, the second switching valve group is always in the third connection position c, and in the low-pressure pumping condition, the second switching valve group is always in the fourth connection position d. It should be noted that the working condition mode of the pumping system is relatively stable, that is to say, the pumping system can maintain in the high-pressure pumping condition for a long time or maintain in the low-pressure pumping condition for a long time. For example, when transporting mortar to a high-rise building, the pumping system needs to maintain a large output capacity so that the mortar can be pumped to a higher floor by the pumping system. At this time, the pumping system is in the high-pressure pumping condition, and the process of transporting mortar to a high-rise building can last for a long time. Therefore, it can ensure that the pumping system is in the high-pressure pumping condition for a long time. Similarly, when transporting mortar to a low-rise building, in order to improve the operation efficiency of the pumping system, at this time, the pumping system is in the low-pressure pumping condition, and the process of transporting mortar to a low-rise building can also last for a long time. Therefore, it can ensure that the pumping system is in the low-pressure pumping condition for a long time. In this way, it is ensured that the second switching valve group can maintain the same connection position for a long time, that is, within a long time, the second switching valve group does not need to frequently switch the connection position, thereby improving the service life of the second switching valve group. Compared with the prior art in which both electromagnetic switching valve groups of the pumping system need to frequently switch the connection position, in the pumping system provided by the present application, only the first switching valve group needs to frequently switch the connection position, and the second switching valve group does not need to frequently switch the connection position. Therefore, the pumping system provided by the present application reduces the number of switching valve groups that are prone to damage, and greatly reduces the maintenance cost of the pumping system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 It is a system connection diagram of the pumping system according to an embodiment provided by the present application;

[0022] Figure 2 It is a system connection diagram of the pumping system according to another embodiment provided by the present application;

[0023] Figure 3 Schematic structural diagram of a pumping system according to an embodiment provided for this application;

[0024] Figure 4 is Figure 3 Cross-sectional view taken along line A-A shown in the figure;

[0025] Figure 5 is Figure 3 Cross-sectional view taken along line B-B shown in the figure.

[0026] Reference numerals: 100, valve body; 110, main oil inlet passage; 120, main oil return passage; 130, first oil passage; 140, second oil passage; 150, third oil passage; 160, fourth oil passage; 170, first passage; 180, second passage; 190, secondary oil return passage; 200, first switching valve group; 210, first communication valve; 220, first solenoid valve; 230, first valve seat; 231, first valve cavity; 240, first valve core; 300, second switching valve group; 310, second valve seat; 311, second valve cavity; 320, second valve core; 330, second communication valve; 340, second solenoid valve; 350, intercommunication oil passage; 400, locking valve group; 410, first locking valve; 420, second locking valve; 430, third solenoid valve; 500, unloading valve; 510, fourth solenoid valve; 600, overflow valve; 700, check valve; 800, first oil cylinder; 810, first piston; 820, first rod chamber; 830, first rodless chamber; 900, second oil cylinder; 910, second piston; 920, second rod chamber; 930, second rodless chamber. Detailed implementation manners

[0027] In the description of this application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to this application.

[0028] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0029] In this application, unless otherwise clearly specified or defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] In this application, unless otherwise clearly specified or defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is at a higher level than the second feature in terms of horizontal height. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is at a lower level than the second feature in terms of horizontal height.

[0031] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific implementations and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0033] In the fields of construction machinery and building machinery, many devices such as concrete pump trucks, excavators, loaders, and backhoe loaders need to rely on hydraulic cylinders to bear loads or perform actions, and the actions of hydraulic cylinders are generally controlled by control valves. For example, when a concrete pump truck is working, the pumping hydraulic cylinder and the swing hydraulic cylinder need to act alternately. The alternate actions between the pumping hydraulic cylinders and between the pumping hydraulic cylinder and the swing hydraulic cylinder need to be controlled by a pumping system. That is, the pumping system controls the mortar pump to supply oil to the pumping hydraulic cylinder or the swing hydraulic cylinder to achieve the alternate actions between the pumping hydraulic cylinders or between the pumping hydraulic cylinder and the swing hydraulic cylinder.

[0034] The pumping system of the prior art has a structure including a base. The base is provided with a main inlet port communicated with a mortar pump, an oil return port communicated with an oil tank, and an oil outlet and an oil return port communicated with two oil ports of two pumping hydraulic cylinders. A first electromagnetic switching valve group and a second electromagnetic switching valve group are connected to the top of the base. The first electromagnetic switching valve group and the second electromagnetic switching valve group respectively control the main inlet port to supply oil to the oil outlet or the oil return port of the two pumping hydraulic cylinders. Moreover, in order to realize the alternate telescopic operation of the two pumping hydraulic cylinders, both the first electromagnetic switching valve group and the second electromagnetic switching valve group need to frequently switch their connection positions. Thus, the service lives of both the first electromagnetic switching valve group and the second electromagnetic switching valve group will be greatly reduced, resulting in a sharp increase in the maintenance cost of the pumping system.

[0035] Please refer to Figures 1 - 5 , to solve the problem that the service lives of the two electromagnetic switching valve groups of the existing pumping system are reduced due to frequent switching, and further increase the maintenance cost of the pumping system, the present application provides a pumping system, which includes a valve body 100, a first switching valve group 200, and a second switching valve group 300. The valve body 100 is provided with a main oil inlet passage 110 capable of communicating the first switching valve group 200 and an oil pump (not shown in the figure) and a main oil return passage 120 capable of communicating the first switching valve group 200 and an external oil tank (not shown in the figure).

[0036] Under the high-pressure pumping working condition:

[0037] When the first switching valve group 200 is in the first connection position a and the second switching valve group 300 is in the third connection position c, the main oil inlet passage 110 sequentially passes through the first switching valve group 200 and the second switching valve group 300 to communicate with the second rodless cavity 930 of the second hydraulic cylinder 900; the second rod chamber 920 of the second hydraulic cylinder 900 communicates with the first rod chamber 820 of the first hydraulic cylinder 800; the first rodless cavity 830 of the first hydraulic cylinder 800 sequentially passes through the second switching valve group 300 and the first switching valve group 200 to communicate with the main oil return passage 120.

[0038] When the first switching valve group 200 is in the second connection position b and the second switching valve group 300 is in the third connection position c, the main oil inlet passage 110 is connected to the first rodless cavity 830 of the first oil cylinder 800 through the first switching valve group 200 and the second switching valve group 300 in sequence; the first rod cavity 820 of the first oil cylinder 800 is connected to the second rod cavity 920 of the second oil cylinder 900; the second rodless cavity 930 of the second oil cylinder 900 is connected to the main oil return passage 120 through the second switching valve group 300 and the first switching valve group 200 in sequence.

[0039] Under the low-pressure pumping condition:

[0040] When the first switching valve group 200 is in the first connection position a and the second switching valve group 300 is in the fourth connection position d, the main oil inlet passage 110 is connected to the second rod cavity 920 of the second oil cylinder 900 through the first switching valve group 200 and the second switching valve group 300 in sequence; the second rodless cavity 930 of the second oil cylinder 900 is connected to the first rodless cavity 830 of the first oil cylinder 800; the first rod cavity 820 of the first oil cylinder 800 is connected to the main oil return passage 120 through the second switching valve group 300 and the first switching valve group 200 in sequence.

[0041] When the first switching valve group 200 is in the second connection position b and the second switching valve group 300 is in the fourth connection position d, the main oil inlet passage 110 is connected to the first rod cavity 820 of the first oil cylinder 800 through the first switching valve group 200 and the second switching valve group 300 in sequence; the first rodless cavity 830 of the first oil cylinder 800 is connected to the second rodless cavity 930 of the second oil cylinder 900; the second rod cavity 920 of the second oil cylinder 900 is connected to the main oil return passage 120 through the second switching valve group 300 and the first switching valve group 200 in sequence.

[0042] It should be noted that the piston in the oil cylinder usually includes a partition part and a push rod part. The push rod part is used to push the partition part to move in the oil cylinder, and the partition part divides the oil cylinder into two parts. The part with the push rod is defined as the rod cavity, and the part without the push rod is defined as the rodless cavity. Therefore, the sizes of the first rodless cavity 830 and the first rod cavity 820 change relatively with the position of the first piston 810 in the first oil cylinder 800. Similarly, the sizes of the second rodless cavity 930 and the second rod cavity 920 change relatively with the position of the second piston 910 in the second oil cylinder 900.

[0043] Thus, in the high-pressure pumping condition, the second switching valve group 300 is always in the third communication position c, and in the low-pressure pumping condition, the second switching valve group 300 is always in the fourth communication position d. It should be noted that the working condition mode of the pumping system is relatively stable, that is to say, the pumping system can maintain in the high-pressure pumping condition for a long time or maintain in the low-pressure pumping condition for a long time. For example, when it is necessary to transport mortar to a high-rise building, the pumping system needs to maintain a large output capacity so that the mortar can be pumped to a higher floor by the pumping system. At this time, the pumping system is in the high-pressure pumping condition, and the process of transporting mortar to a high-rise building can last for a long time. Therefore, it can ensure that the pumping system is in the high-pressure pumping condition for a long time. Similarly, when it is necessary to transport mortar to a low-rise building, in order to improve the operation efficiency of the pumping system, at this time, the pumping system is in the low-pressure pumping condition, and the process of transporting mortar to a low-rise building can also last for a long time. Therefore, it can ensure that the pumping system is in the low-pressure pumping condition for a long time. In this way, it is ensured that the second switching valve group 300 can maintain the same communication position for a long time, that is, within a long time, the second switching valve group 300 does not need to frequently switch the communication position, thereby improving the service life of the second switching valve group 300. Compared with the prior art in which both electromagnetic switching valve groups of the pumping system need to frequently switch the communication position, in the pumping system provided in this application, only the first switching valve group 200 needs to frequently switch the communication position, and the second switching valve group 300 does not need to frequently switch the communication position. Therefore, the pumping system provided in this application reduces the number of switching valve groups that are prone to damage, and greatly reduces the maintenance cost of the pumping system.

[0044] Further, in one embodiment, as Figure 5 shown, the first switching valve group 200 includes a first valve seat 230 and a first valve core 240. The first valve seat 230 is provided with a first valve cavity 231. The first valve core 240 is movably arranged in the first valve cavity 231 to control the first switching valve group 200 to be in the first communication position a or the second communication position b; the second switching valve group 300 includes a second valve seat 310 and a second valve core 320. The second valve seat 310 is provided with a second valve cavity 311. The second valve core 320 is movably arranged in the second valve cavity 311 to control the second switching valve group 300 to be in the third communication position c or the fourth communication position d, and the fitting clearance between the second valve core 320 and the second valve seat 310 is smaller than the fitting clearance between the first valve core 240 and the first valve seat 230.

[0045] Generally, the first piston 810 needs to move frequently within the first oil cylinder 800. Therefore, the clearance between the first piston 810 and the first oil cylinder 800 is relatively large, which helps to reduce the moving resistance of the first piston 810, thereby reducing the power consumption of the pumping system. Similarly, the second piston 910 needs to move frequently within the second oil cylinder 900. Therefore, the clearance between the second piston 910 and the second oil cylinder 900 is relatively large, which helps to reduce the moving resistance of the second piston 910, thereby reducing the power consumption of the pumping system. However, with such a setting, oil leakage may occur in the first piston 810 or the second piston 910 during the work process, which may lead to the backflow of the mortar in the mortar conveying pipeline. Therefore, in this embodiment, the clearance between the second spool 320 and the second valve seat 310 is set to be smaller than the clearance between the first spool 240 and the first valve seat 230. At the second switching valve group 300, the leakage of the pressure oil is blocked, thus avoiding the oil leakage of the first piston 810 or the second piston 910 during the work process. And, since the switching frequency of the second switching valve group 300 is relatively low, such a setting will not affect the switching efficiency of the pumping system. Further, the relatively large clearance between the first spool 240 and the first valve seat 230 is beneficial to improving the switching flexibility of the first switching valve group 200 and the working efficiency of the pumping system.

[0046] Furthermore, in one embodiment, as Figure 1 and Figure 2 shown, the first switching valve group 200 includes a first communication valve 210 and two first solenoid valves 220. The two first solenoid valves 220 are respectively connected to both ends of the first communication valve 210 to drive the first communication valve 210 to be in the first communication position a, the second communication position b, or the first intermediate disconnection position e, where the first intermediate disconnection position e is provided between the first communication position a and the second communication position b.

[0047] Similarly, in one embodiment, as Figure 1 shown, the second switching valve group 300 includes a second communication valve 330 and two second solenoid valves 340. The two second solenoid valves 340 are respectively connected to both ends of the second communication valve 330 to drive the second communication valve 330 to be in the third communication position c, the fourth communication position d, or the second intermediate disconnection position f, where the second intermediate disconnection position f is provided between the third communication position c and the fourth communication position d.

[0048] In another embodiment, as Figure 2 shown, the second switching valve group 300 includes a second communication valve 330 and one second solenoid valve 340. The second solenoid valve 340 is connected to one end of the second communication valve 330 to drive the second communication valve 330 to be in the third communication position c or the fourth communication position d.

[0049] Specifically, in one embodiment, as Figure 1 and Figure 2 shown, the valve body 100 is further provided with a first oil passage 130 capable of connecting the second switching valve group 300 and the first rod chamber 820, a second oil passage 140 capable of connecting the second switching valve group 300 and the first rodless chamber 830, a third oil passage 150 capable of connecting the second switching valve group 300 and the second rod chamber 920, and a fourth oil passage 160 capable of connecting the second switching valve group 300 and the second rodless chamber 930. A first passage 170 and a second passage 180 are provided between the first switching valve group 200 and the second switching valve group 300.

[0050] In the high-pressure pumping working condition:

[0051] When the first switching valve group 200 is in the first connection position a and the second switching valve group 300 is in the third connection position c, the main oil inlet passage 110 is sequentially connected to the first switching valve group 200, the second passage 180, the second switching valve group 300, the fourth oil passage 160, and the second rodless chamber 930 of the second oil cylinder 900; the second rod chamber 920 of the second oil cylinder 900 is connected to the first rod chamber 820 of the first oil cylinder 800; the first rodless chamber 830 of the first oil cylinder 800 is sequentially connected to the second oil passage 140, the second switching valve group 300, the first passage 170, the first switching valve group 200, and the main oil return passage 120.

[0052] In this way, the pressurized oil fluid sequentially enters the second rodless chamber 930 of the second oil cylinder 900 through the main oil inlet passage 110, the first switching valve group 200, the second passage 180, the second switching valve group 300, and the fourth oil passage 160, and drives the second piston 910 in the second oil cylinder 900 to move towards the second rod chamber 920 to do work. Then, the pressurized oil fluid in the second rod chamber 920 of the second oil cylinder 900 is pressed into the first rod chamber 820 of the first oil cylinder 800, and the pressurized oil fluid drives the first piston 810 in the first oil cylinder 800 to move towards the first rodless chamber 830 to do work. After that, the pressurized oil fluid in the first rodless chamber 830 of the first oil cylinder 800 sequentially enters the main oil return passage 120 through the second oil passage 140, the second switching valve group 300, the first passage 170, and the first switching valve group 200.

[0053] When the first switching valve group 200 is in the second communication position b and the second switching valve group 300 is in the third communication position c, the main oil inlet passage 110 is sequentially communicated with the first switching valve group 200, the first passage 170, the second switching valve group 300, the second oil passage 140 and the first rodless cavity 830 of the first oil cylinder 800; the first rod chamber 820 of the first oil cylinder 800 is communicated with the second rod chamber 920 of the second oil cylinder 900; the second rodless cavity 930 of the second oil cylinder 900 is sequentially communicated with the fourth oil passage 160, the second switching valve group 300, the second passage 180, the first switching valve group 200 and the main oil return passage 120.

[0054] In this way, the pressurized oil fluid sequentially enters the first rodless cavity 830 of the first oil cylinder 800 through the main oil inlet passage 110, the first switching valve group 200, the first passage 170, the second switching valve group 300 and the second oil passage 140, and drives the first piston 810 of the first oil cylinder 800 to move towards the first rod chamber 820 to do work. Then, the pressurized oil fluid in the first rod chamber 820 of the first oil cylinder 800 is pressed into the second rod chamber 920 of the second oil cylinder 900, and the pressurized oil fluid drives the second piston 910 of the second oil cylinder 900 to move towards the second rodless cavity 930 to do work. After that, the pressurized oil fluid in the second rodless cavity 930 of the second oil cylinder 900 sequentially enters the main oil return passage 120 through the fourth oil passage 160, the second switching valve group 300, the second passage 180 and the first switching valve group 200.

[0055] In the low-pressure pumping condition:

[0056] When the first switching valve group 200 is in the first communication position a and the second switching valve group 300 is in the fourth communication position d, the main oil inlet passage 110 is sequentially communicated with the first switching valve group 200, the second passage 180, the second switching valve group 300, the third oil passage 150 and the second rod chamber 920 of the second oil cylinder 900; the second rodless cavity 930 of the second oil cylinder 900 is communicated with the first rodless cavity 830 of the first oil cylinder 800; the first rod chamber 820 of the first oil cylinder 800 is sequentially communicated with the first oil passage 130, the second switching valve group 300, the first passage 170, the first switching valve group 200 and the main oil return passage 120.

[0057] Thus, the pressurized hydraulic fluid sequentially passes through the main inlet passage 110, the first switching valve group 200, the second passage 180, the second switching valve group 300, and the third oil passage 150 to enter the second rod chamber 920 of the second oil cylinder 900, and drives the second piston 910 of the second oil cylinder 900 to move towards the second rodless chamber 930 to do work. After that, the pressurized hydraulic fluid in the second rodless chamber 930 of the second oil cylinder 900 is pressed into the first rodless chamber 830 of the first oil cylinder 800, and the pressurized hydraulic fluid drives the first piston 810 to move towards the first rod chamber 820 to do work. Then, the pressurized hydraulic fluid in the first rod chamber 820 of the first oil cylinder 800 sequentially passes through the first oil passage 130, the second switching valve group 300, the first passage 170, and the first switching valve group 200 to enter the main return oil passage 120.

[0058] When the first switching valve group 200 is in the second communication position b and the second switching valve group 300 is in the fourth communication position d, the main inlet passage 110 is sequentially communicated with the first switching valve group 200, the first passage 170, the second switching valve group 300, the first oil passage 130, and the first rod chamber 820 of the first oil cylinder 800; the first rodless chamber 830 of the first oil cylinder 800 is communicated with the second rodless chamber 930 of the second oil cylinder 900; the second rod chamber 920 of the second oil cylinder 900 is sequentially communicated with the third oil passage 150, the second switching valve group 300, the second passage 180, the first switching valve group 200, and the main return oil passage 120.

[0059] Thus, the pressurized hydraulic fluid sequentially passes through the main inlet passage 110, the first switching valve group 200, the first passage 170, the second switching valve group 300, and the first oil passage 130 to enter the first rod chamber 820 of the first oil cylinder 800, and drives the first piston 810 of the first oil cylinder 800 to move towards the first rodless chamber 830 to do work. After that, the pressurized hydraulic fluid in the first rodless chamber 830 of the first oil cylinder 800 is pressed into the second rodless chamber 930 of the second oil cylinder 900, and the pressurized hydraulic fluid drives the second piston 910 to move towards the second rod chamber 920 to do work. Then, the pressurized hydraulic fluid in the second rod chamber 920 of the second oil cylinder 900 sequentially passes through the third oil passage 150, the second switching valve group 300, the second passage 180, and the first switching valve group 200 to enter the main return oil passage 120.

[0060] Further, in one embodiment, as Figure 1 and Figure 2As shown, an interconnected oil passage 350 is provided in the second switching valve group 300. When the first switching valve group 200 is in the first connection position a and the second switching valve group 300 is in the third connection position c, the second rodless chamber 920 of the second oil cylinder 900 is sequentially connected to the third oil passage 150, the interconnected oil passage 350, the first oil passage 130, and the first rodless chamber 820 of the first oil cylinder 800. When the first switching valve group 200 is in the second connection position b and the second switching valve group 300 is in the third connection position c, the first rodless chamber 820 of the first oil cylinder 800 is sequentially connected to the first oil passage 130, the interconnected oil passage 350, the third oil passage 150, and the second rodless chamber 920 of the second oil cylinder 900.

[0061] In this way, the structure of the pumping system is simplified.

[0062] Further, in an embodiment, as Figure 1 and Figure 2 shown, the pumping system further includes a locking valve group 400. When the first switching valve group 200 is in the first connection position a and the second switching valve group 300 is in the fourth connection position d, the locking valve group 400 opens, and the second rodless chamber 930 of the second oil cylinder 900 is connected to the first rodless chamber 830 of the first oil cylinder 800 through the locking valve group 400. When the first switching valve group 200 is in the second connection position b and the second switching valve group 300 is in the fourth connection position d, the locking valve group 400 opens, and the first rodless chamber 830 of the first oil cylinder 800 is connected to the second rodless chamber 930 of the second oil cylinder 900 through the locking valve group 400.

[0063] In this way, the connection path between the first rodless chamber 830 of the first oil cylinder 800 and the second rodless chamber 930 of the second oil cylinder 900 is shortened, thereby greatly improving the alternating operation efficiency of the first oil cylinder 800 and the second oil cylinder 900, and further improving the operation efficiency of the pumping system.

[0064] Moreover, it should be noted that when the first switching valve group 200 is in the first connection position a and the second switching valve group 300 is in the third connection position c, the locking valve group 400 closes, and the second rodless chamber 930 of the second oil cylinder 900 is disconnected from the first rodless chamber 830 of the first oil cylinder 800.

[0065] In this way, it is ensured that the pressure oil in the first rodless chamber 830 of the first oil cylinder 800 will not enter the second rodless chamber 930 of the second oil cylinder 900 through the locking valve group 400, and further ensured that the pressure oil in the first rodless chamber 830 of the first oil cylinder 800 can push the first piston 810 in the first oil cylinder 800 to move and do work.

[0066] When the first switching valve group 200 is in the second communication position b and the second switching valve group 300 is in the third communication position c, the locking valve group 400 is closed, and the first rodless cavity 830 of the first oil cylinder 800 is disconnected from the second rodless cavity 930 of the second oil cylinder 900.

[0067] In this way, it is ensured that the pressurized oil in the second rodless cavity 930 of the second oil cylinder 900 will not enter the first rodless cavity 830 of the first oil cylinder 800 through the locking valve group 400, and further ensure that the pressurized oil in the second rodless cavity 930 of the second oil cylinder 900 can push the second piston 910 in the second oil cylinder 900 to move and do work.

[0068] Furthermore, in one embodiment, as Figure 1 and Figure 2 shown, the locking valve group 400 includes a first locking valve 410, a second locking valve 420, and a third solenoid valve 430. The third solenoid valve 430 can drive the first locking valve 410 and the second locking valve 420 to open or close.

[0069] Specifically, in one embodiment, as Figure 1 and Figure 2 shown, the first locking valve 410 and the second locking valve 420 are arranged in parallel between the first rodless cavity 830 and the second rodless cavity 930.

[0070] In one embodiment, as Figure 1 and Figure 2 shown, the pumping system further includes a relief valve 500 and a fourth solenoid valve 510. The main oil inlet passage 110 can communicate with the main oil return passage 120 and the secondary oil return passage 190 through the relief valve 500. The fourth solenoid valve 510 can drive the relief valve 500 to open or close. When the relief valve 500 is open, the pumping system is in a relief state. At this time, the first oil cylinder 800 and the second oil cylinder 900 do not work. When the relief valve 500 is closed, the pumping system starts to build up hydraulic pressure. At this time, the first oil cylinder 800 and the second oil cylinder 900 start to work.

[0071] In one embodiment, as Figure 1 and Figure 2 shown, the pumping system further includes a pressure relief valve 600. The main oil inlet passage 110 can communicate with the main oil return passage 120 and the secondary oil return passage 190 through the pressure relief valve 600.

[0072] In one embodiment, as Figure 1 and Figure 2 shown, the pumping system further includes a check valve 700. The main oil inlet passage 110 communicates with the first switching valve group 200 through the check valve 700. In this way, the pressurized oil in the first switching valve group 200 can be prevented from flowing back through the main oil inlet passage 110.

[0073] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0074] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application shall be subject to the appended claims.

Claims

1. A pumping system, characterized in that, It includes a valve body (100), a first switching valve group (200) and a second switching valve group (300). The valve body (100) is provided with a main oil inlet passage (110) capable of connecting the first switching valve group (200) and an oil pump, and a main oil return passage (120) capable of connecting the first switching valve group (200) and an external oil tank; Under the high-pressure pumping condition: When the first switching valve group (200) is in the first connection position a and the second switching valve group (300) is in the third connection position c, the main oil inlet passage (110) is connected to the second rodless cavity (930) of the second oil cylinder (900) through the first switching valve group (200) and the second switching valve group (300) in sequence; the second rod chamber (920) of the second oil cylinder (900) is connected to the first rod chamber (820) of the first oil cylinder (800); the first rodless cavity (830) of the first oil cylinder (800) is connected to the main oil return passage (120) through the second switching valve group (300) and the first switching valve group (200) in sequence; When the first switching valve group (200) is in the second connection position b and the second switching valve group (300) is in the third connection position c, the main oil inlet passage (110) is connected to the first rodless cavity (830) of the first oil cylinder (800) through the first switching valve group (200) and the second switching valve group (300) in sequence; the first rod chamber (820) of the first oil cylinder (800) is connected to the second rod chamber (920) of the second oil cylinder (900); the second rodless cavity (930) of the second oil cylinder (900) is connected to the main oil return passage (120) through the second switching valve group (300) and the first switching valve group (200) in sequence; Under the low-pressure pumping condition: When the first switching valve group (200) is in the first connection position a and the second switching valve group (300) is in the fourth connection position d, the main oil inlet passage (110) is connected to the second rod chamber (920) of the second oil cylinder (900) through the first switching valve group (200) and the second switching valve group (300) in sequence; the second rodless cavity (930) of the second oil cylinder (900) is connected to the first rodless cavity (830) of the first oil cylinder (800); the first rod chamber (820) of the first oil cylinder (800) is connected to the main oil return passage (120) through the second switching valve group (300) and the first switching valve group (200) in sequence; When the first switching valve group (200) is in the second communication position b and the second switching valve group (300) is in the fourth communication position d, the main oil inlet passage (110) communicates with the first rod chamber (820) of the first oil cylinder (800) through the first switching valve group (200) and the second switching valve group (300) in sequence; the first rodless chamber (830) of the first oil cylinder (800) communicates with the second rodless chamber (930) of the second oil cylinder (900); the second rod chamber (920) of the second oil cylinder (900) communicates with the main oil return passage (120) through the second switching valve group (300) and the first switching valve group (200) in sequence.

2. The pumping system according to claim 1, characterized in that, The first switching valve group (200) includes a first valve seat (230) and a first valve core (240). The first valve seat (230) is provided with a first valve chamber (231). The first valve core (240) is movably arranged in the first valve chamber (231) to control the first switching valve group (200) to be in the first communication position a or the second communication position b; the second switching valve group (300) includes a second valve seat (310) and a second valve core (320). The second valve seat (310) is provided with a second valve chamber (311). The second valve core (320) is movably arranged in the second valve chamber (311) to control the second switching valve group (300) to be in the third communication position c or the fourth communication position d. Moreover, the fitting clearance between the second valve core (320) and the second valve seat (310) is smaller than the fitting clearance between the first valve core (240) and the first valve seat (230).

3. The pumping system according to claim 1, characterized in that, The first switching valve group (200) includes a first communication valve (210) and two first electromagnetic valves (220). The two first electromagnetic valves (220) are respectively connected to both ends of the first communication valve (210) to drive the first communication valve (210) to be in the first communication position a, the second communication position b or the first intermediate disconnection position e, where the first intermediate disconnection position e is arranged between the first communication position a and the second communication position b. The second switching valve group (300) includes a second communication valve (330) and two second electromagnetic valves (340). The two second electromagnetic valves (340) are respectively connected to both ends of the second communication valve (330) to drive the second communication valve (330) to be in the third communication position c, the fourth communication position d or the second intermediate disconnection position f, where the second intermediate disconnection position f is arranged between the third communication position c and the fourth communication position d.

4. The pumping system according to claim 1, wherein The second switching valve group (300) includes a second communication valve (330) and a second electromagnetic valve (340). The second electromagnetic valve (340) is connected to one end of the second communication valve (330) to drive the second communication valve (330) to be in the third communication position c or the fourth communication position d.

5. The pumping system according to claim 1, characterized in that, The valve body (100) is further provided with a first oil passage (130) capable of connecting the second switching valve group (300) and the first rod chamber (820), a second oil passage (140) capable of connecting the second switching valve group (300) and the first rodless chamber (830), a third oil passage (150) capable of connecting the second switching valve group (300) and the second rod chamber (920), and a fourth oil passage (160) capable of connecting the second switching valve group (300) and the second rodless chamber (930); a first passage (170) and a second passage (180) are provided between the first switching valve group (200) and the second switching valve group (300); Under the high-pressure pumping condition: When the first switching valve group (200) is in the first connection position a and the second switching valve group (300) is in the third connection position c, the main oil inlet passage (110) sequentially connects the first switching valve group (200), the second passage (180), the second switching valve group (300), the fourth oil passage (160) and the second rodless chamber (930) of the second oil cylinder (900); the second rod chamber (920) of the second oil cylinder (900) is connected to the first rod chamber (820) of the first oil cylinder (800); the first rodless chamber (830) of the first oil cylinder (800) sequentially connects the second oil passage (140), the second switching valve group (300), the first passage (170), the first switching valve group (200) and the main oil return passage (120); When the first switching valve group (200) is in the second connection position b and the second switching valve group (300) is in the third connection position c, the main oil inlet passage (110) sequentially connects the first switching valve group (200), the first passage (170), the second switching valve group (300), the second oil passage (140) and the first rodless chamber (830) of the first oil cylinder (800); the first rod chamber (820) of the first oil cylinder (800) is connected to the second rod chamber (920) of the second oil cylinder (900); the second rodless chamber (930) of the second oil cylinder (900) sequentially connects the fourth oil passage (160), the second switching valve group (300), the second passage (180), the first switching valve group (200) and the main oil return passage (120); Under the low-pressure pumping condition: When the first switching valve group (200) is in the first communication position a and the second switching valve group (300) is in the fourth communication position d, the main oil inlet passage (110) communicates with the first switching valve group (200), the second passage (180), the second switching valve group (300), the third oil passage (150), and the second rodless cavity (920) of the second oil cylinder (900) in sequence; the second rodless cavity (930) of the second oil cylinder (900) communicates with the first rodless cavity (830) of the first oil cylinder (800); the first rodless cavity (820) of the first oil cylinder (800) communicates with the first oil passage (130), the second switching valve group (300), the first passage (170), the first switching valve group (200), and the main oil return passage (120) in sequence; When the first switching valve group (200) is in the second communication position b and the second switching valve group (300) is in the fourth communication position d, the main oil inlet passage (110) communicates with the first switching valve group (200), the first passage (170), the second switching valve group (300), the first oil passage (130), and the first rodless cavity (820) of the first oil cylinder (800) in sequence; the first rodless cavity (830) of the first oil cylinder (800) communicates with the second rodless cavity (930) of the second oil cylinder (900); the second rodless cavity (920) of the second oil cylinder (900) communicates with the third oil passage (150), the second switching valve group (300), the second passage (180), the first switching valve group (200), and the main oil return passage (120) in sequence.

6. The pumping system according to claim 5, characterized in that, An intercommunicating oil passage (350) is provided in the second switching valve group (300); When the first switching valve group (200) is in the first communication position a and the second switching valve group (300) is in the third communication position c, the second rodless cavity (920) of the second oil cylinder (900) communicates with the third oil passage (150), the intercommunicating oil passage (350), the first oil passage (130), and the first rodless cavity (820) of the first oil cylinder (800) in sequence; When the first switching valve group (200) is in the second communication position b and the second switching valve group (300) is in the third communication position c, the first rodless cavity (820) of the first oil cylinder (800) communicates with the first oil passage (130), the intercommunicating oil passage (350), the third oil passage (150), and the second rodless cavity (920) of the second oil cylinder (900) in sequence.

7. The pumping system according to claim 1, wherein The pumping system further includes a locking valve group (400); When the first switching valve group (200) is in the first communication position a and the second switching valve group (300) is in the fourth communication position d, the locking valve group (400) is opened, and the second rodless cavity (930) of the second oil cylinder (900) communicates with the first rodless cavity (830) of the first oil cylinder (800) through the locking valve group (400); When the first switching valve group (200) is in the second communication position b and the second switching valve group (300) is in the fourth communication position d, the locking valve group (400) is opened, and the first rodless chamber (830) of the first oil cylinder (800) communicates with the second rodless chamber (930) of the second oil cylinder (900) through the locking valve group (400); When the first switching valve group (200) is in the first communication position a and the second switching valve group (300) is in the third communication position c, the locking valve group (400) is closed, and the second rodless chamber (930) of the second oil cylinder (900) is disconnected from the first rodless chamber (830) of the first oil cylinder (800); When the first switching valve group (200) is in the second communication position b and the second switching valve group (300) is in the third communication position c, the locking valve group (400) is closed, and the first rodless chamber (830) of the first oil cylinder (800) is disconnected from the second rodless chamber (930) of the second oil cylinder (900).

8. The pumping system according to claim 7, characterized in that The locking valve group (400) includes a first locking valve (410), a second locking valve (420), and a third solenoid valve (430), and the third solenoid valve (430) can drive the first locking valve (410) and the second locking valve (420) to open or close.

9. The pumping system according to claim 8, characterized in that, The first locking valve (410) and the second locking valve (420) are arranged in parallel between the first rodless chamber (830) and the second rodless chamber (930).

10. The pumping system according to claim 1, characterized in that, The pumping system further includes a check valve (700), and the main oil inlet passage (110) communicates with the first switching valve group (200) through the check valve (700).

Images