A fluid control device and control system including the same

Abstract

The application discloses a fluid control device and a control system thereof. The fluid control device comprises a control valve, an inner cavity of a valve body of the control valve is provided with a supply medium cavity and a return medium cavity, the valve body is provided with a supply medium inlet channel and a supply medium outlet channel which are communicated with the supply medium cavity, and the valve body is provided with a return medium inlet channel and a return medium outlet channel which are communicated with the return medium cavity; the control valve further comprises a supply medium on-off control switch and a return medium on-off control switch, the supply medium on-off control switch controls opening and closing of the supply medium outlet channel, and the return medium on-off control switch controls opening and closing of the return medium inlet channel; the fluid control device further comprises a negative pressure generating device, the return medium cavity is connected with the negative pressure generating device, and when the negative pressure generating device is in a working condition of forming negative pressure, fluid in the return medium cavity flows out. The fluid control device can replace a traditional multi-way valve, and can provide a technical basis for digitalization and intelligent control of a hydraulic control system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fluid transmission technology, especially the field of hydraulic transmission technology, and particularly relates to a fluid control device and a control system comprising the same. BACKGROUND

[0002] Fluid transmission technology is widely used in various industries. It is particularly widely used in the field of engineering machinery. Engineering machinery (such as loaders, excavators, cranes, concrete pump trucks, etc. with hydraulic systems) has the advantages of high work efficiency and strong work capacity and is widely used. It can be said that the emergence of engineering machinery makes the operation of building high-rise buildings, erecting high-speed rails, and installing some special equipment simpler, more efficient, more labor-saving, and more cost-effective, and even enables work that was previously impossible to be completed. In the process of modernization, engineering machinery plays a vital role. Although existing engineering machinery can meet the requirements of most engineering, most existing engineering machinery still needs to be operated by an operator on site to implement related work. In some special working conditions and high-risk application scenarios, it may even pose a great threat to the operator's life. Even if individual hydraulic systems can be remotely operated by artificial means through sensing technology, due to the non-linear relationship between flow and pressure at the throttle, it is difficult to establish a linear correspondence between flow or pressure and modern electric control pulse signals, thereby making it difficult to achieve intelligent control through the control program of a chip. At most, it can achieve remote analog control by a specific person. Taking excavators as an example, hydraulically controlled excavators are indispensable mechanical equipment in various earthwork construction, especially in special working conditions such as earthquake relief, toxic environments, dangerous tunnels, fire fighting and rescue, cliff opening, and explosion site cleaning. The operation of the operator is extremely dangerous. If the intelligent control of engineering machinery can be realized, engineering machinery will not only liberate labor but also improve work safety, and will also greatly improve the work capacity of engineering machinery and reduce the cost of use and maintenance. However, to achieve intelligent control of equipment containing a hydraulic control system, the cost of achieving intelligent control through timely feedback adjustment is too high, and the current technical conditions are difficult to achieve. Therefore, in combination with the technical characteristics of existing electronic and electrical discrete digital control, the intelligent control of hydraulic technology must first choose the discretization and digitization of the hydraulic system. The existing hydraulic control system is limited by the structure, function defects, and combination defects of its constituent elements, making the various functions of the hydraulic control system coupled and restricted, making it difficult to achieve the discretization and digitization of the hydraulic medium. Under the current technical strength, the intelligent control of the hydraulic control system is only a fitting algorithm that is constantly adjusted, and it is not easy to achieve quantitative control. Therefore, it is necessary to rethink and redesign the various constituent elements of the existing hydraulic control system and the combination between elements.

[0003] In any existing hydraulic control system, the hydraulic control system needs to have multiple functions (for example, the existing excavator needs to control the hydraulic actuator through the hydraulic control system to realize the functions of the variable amplitude between the arms, the hydraulic walking, and the hydraulic control rotation), and for this purpose, a multi-way valve must be provided. However, in order to save installation space and facilitate operation, the multi-way valve is often formed by stacking single valves, and shares an oil supply oil path and an oil return oil path. Whether in series or in parallel, the oil supply pressure and flow between the single valves are coupled and interfere with each other, so it is difficult to achieve digitization, discretization, and even precise control and intelligent control.

[0004] The existing multi-way valve has a relatively single demand for each actuator. In order to facilitate processing and improve processing accuracy, the multi-way valve is stacked by multiple single valves according to the needs of functions and working conditions and connected by bolts. Although the processing accuracy of the single valve can be well guaranteed, due to the existence of factors such as processing accuracy and installation deformation, it inevitably leads to problems such as inter-valve leakage and valve core sticking in the existing multi-way valve, which seriously affects the reliability, stability, and safety of the hydraulic control system including the multi-way valve.

[0005] In the existing multi-way valve, a single valve often controls the opening and closing of the oil supply oil path, the oil inlet of the actuator, the oil return oil path, and the oil outlet of the actuator with a common valve core. The switching states of different oil paths are coupled together to simultaneously change the direction of fluid flow or adjust the flow of the actuator through the size of the throttle opening. The mutual influence between the actuators inevitably occurs, which seriously affects the realization of discretization, digitization, and intelligent control of the existing fluid system including the multi-way valve.

[0006] In addition to the above-mentioned defects, the equipment including the hydraulic control system often has a problem of large vibration during use, so generally the connection bolt is thickened and the connection locking torque is increased to overcome the inter-valve leakage problem of the multi-way valve formed by stacking multiple single valves. However, with the passage of time and the influence of factors such as fatigue stretching of the bolt, the inter-valve leakage problem still occurs after a period of use. It is worth noting that due to the increase of the connection locking torque of the bolt, the deformation of the valve body of the multi-way valve caused by factors such as parallelism, flatness of the valve body connection surface, and material creep will affect the movement of the precision valve core, and even cause the valve core sticking problem inside the multi-way valve. With the increase of the length of the connection bolt, it will cause uneven stress and fatigue creep. Therefore, the thickness of each piece of the existing multi-way valve is minimized, which will make the flow passage of the multi-way valve narrow and curved, and the pressure loss will increase sharply, thereby making the existing multi-way valve have many technical bottlenecks that are difficult to avoid.

[0007] In addition, in the prior art, the actuating element (especially a hydraulic cylinder) needs to discharge the fluid medium on the non-working side from its interior, and due to the blocking effect of the throttle and pipeline elements, the discharge part has back pressure, and the power generated by the back pressure is, in most cases, an invalid or harmful power consumption that hinders the normal work of the actuating element, belongs to an invalid power that causes the fluid medium to heat up, and also causes the response delay of the actuating element, affecting the working efficiency. Therefore, a negative pressure channel should be established for positive work, and for this purpose, the application comprises a negative pressure generating device.

[0008] In order to solve the discretization, digitization and intelligent control of the existing hydraulic control system, it is necessary to combine a new type of discretization and digitization control system to innovatively conceive and design the existing multi-way valve, so as to overcome the problems of the existing multi-way valve, such as large reversing dead zone, more coupling factors of control, and lack of flexible adaptation to the requirements of the variable working conditions of the actuating element. Therefore, the applicant proposes a control valve and a control system applying the control valve, which can solve at least the above technical problems of the existing multi-way valve.

[0009] It should be noted that the above content belongs to the technical cognition range of the inventor and does not necessarily constitute the prior art. SUMMARY

[0010] The application provides a fluid control device and a control system comprising the same to solve at least one of the above technical problems.

[0011] The technical scheme adopted by the application is as follows:

[0012] A fluid control device comprises a control valve, the control valve comprises a valve body, the valve body is internally provided with a flow medium cavity and a return flow medium cavity, the valve body is provided with a flow medium inlet channel and a flow medium outlet channel communicating with the flow medium cavity, and the valve body is provided with a return flow medium inlet channel and a return flow medium outlet channel communicating with the return flow medium cavity;

[0013] The control valve further comprises a flow passage control switch and a return flow passage control switch, the flow passage control switch controls the opening and closing of the flow medium outlet channel, and the return flow passage control switch controls the opening and closing of the return flow medium inlet channel;

[0014] The flow medium cavity provides fluid medium for an actuating element, and the return flow medium cavity accommodates the returned fluid medium;

[0015] The flow passage control switch and the return flow passage control switch are driven by a driving unit;

[0016] The fluid control device further comprises a negative pressure generating device, and the backflow medium cavity is connected with the negative pressure generating device, so that the fluid in the backflow medium cavity flows out when the negative pressure generating device is in a working condition of forming negative pressure; and the negative pressure generating device serves as a passage for the fluid medium in the backflow medium cavity to flow out when the negative pressure generating device is in a non-working condition.

[0017] Further, the negative pressure generating device is further selectively provided as a cylinder-piston mechanism, the cylinder-piston mechanism comprises a cylinder and a piston, the piston and the cylinder form a first cavity with variable volume, the cylinder is provided with a first medium inlet and a first medium outlet connected with the first cavity; the backflow medium cavity is connected with the first medium inlet through the backflow medium discharge passage, a first switch unit for controlling the opening and closing of the backflow medium discharge passage is arranged on the backflow medium discharge passage, and a second switch unit is arranged on the fluid passage downstream of the first medium outlet;

[0018] When the volume of the first cavity increases, the first switch unit on the backflow medium discharge passage in the working flow path is in an open state, and the second switch unit is in a closed state;

[0019] When the volume of the first cavity decreases, the first switch unit on the backflow medium discharge passage in the working flow path is in a closed state, and the second switch unit is in an open state.

[0020] The application further discloses a fluid control device, comprising a control valve, the control valve comprises a valve body, two or more than two supply medium cavities and at least two backflow medium cavities are arranged in the valve body, each of the supply medium cavities and two or more than two backflow medium cavities are matched and serve as parts of the same flow path;

[0021] Each of the supply medium cavities is connected with a supply medium inlet passage arranged on the valve body and at least one supply medium discharge passage arranged on the valve body, and a supply flow control switch is arranged on each of the supply medium discharge passages;

[0022] Each of the backflow medium cavities is connected with at least one backflow medium inlet passage arranged on the valve body and a backflow medium discharge passage arranged on the valve body, and a backflow flow control switch is arranged on each of the backflow medium inlet passages;

[0023] The supply medium cavities provide fluid medium for an execution element, and the backflow medium cavities accommodate backflow fluid medium; the supply flow control switch and the backflow flow control switch are driven by a driving unit;

[0024] The fluid control device further comprises a negative pressure generating device, the backflow medium cavities are connected to the negative pressure generating device, the backflow medium cavities on the valve body are respectively connected to the negative pressure generating device, when the negative pressure generating device is in a working condition of forming negative pressure, the fluid in the backflow medium cavities flows out; when the negative pressure generating device is in a non-working condition, the negative pressure generating device is used as a passage for discharging fluid in the backflow medium cavities.

[0025] Further, the negative pressure generating device is further selectively provided as a cylinder-piston mechanism, the cylinder-piston mechanism comprises a cylinder and a piston, the piston and the cylinder form a first cavity and a second cavity with variable volumes, the cylinder is provided with a first medium inlet and a first medium outlet connected to the first cavity and a second medium inlet and a second medium outlet connected to the second cavity;

[0026] Each of part of the backflow medium cavities is connected to the first cavity through a backflow medium discharge channel and a first medium inlet, each of the rest of the backflow medium cavities is connected to the second cavity through a backflow medium discharge channel and a second medium inlet, a first switch unit is arranged on each of the backflow medium discharge channels, the backflow medium cavities connected to the first cavity are connected to at least one of the backflow medium cavities connected to the second cavity through a third switch unit;

[0027] A second switch unit is arranged on the fluid channel at or downstream of the first medium outlet and the fluid channel at or downstream of the second medium outlet, respectively;

[0028] When the volume of the first cavity increases, the first switch unit on the backflow medium discharge channel in the working flow path and connected to the first cavity is in an open state, and the second switch unit connected to the first cavity is in a closed state;

[0029] When the volume of the first cavity decreases, the first switch unit on the backflow medium discharge channel in the working flow path and connected to the first cavity is in a closed state, and the second switch unit connected to the first cavity is in an open state;

[0030] When the volume of the second cavity increases, the first switch unit on the backflow medium discharge channel in the working flow path and connected to the second cavity is in an open state, and the second switch unit connected to the second cavity is in a closed state;

[0031] When the volume of the second cavity decreases, the first switch unit on the backflow medium discharge channel in the working flow path and connected to the second cavity is in a closed state, and the second switch unit connected to the second cavity is in an open state;

[0032] When the pressure difference in the return medium cavity connected to the third switch unit is below the set value, the third switch unit is in the off state; when the pressure difference in the return medium cavity connected to the third switch unit is above the set value, the third switch unit is in the on state.

[0033] Further selectively driving the cylinder piston mechanism by the reciprocating driving mechanism to make the piston reciprocate in the cylinder, the third switch unit comprises a first one-way switch and a second one-way switch arranged in parallel, the on direction of the first one-way switch is arranged reversely to the on direction of the second one-way switch, when the piston reciprocates, the first one-way switch and the second one-way switch are selectively opened, so that the first cavity and the second cavity can both obtain fluid medium from the return medium cavity connected thereto during the reciprocation of the piston.

[0034] During operation, further selectively selecting the flow supply on-off control switch to make the flow supply medium discharge passage continuously in the on and off alternating working state, so that the control valve supplies pulse fluid medium externally; or, selectively making the flow supply on-off control switch make the flow supply medium discharge passage continuously in the on and off alternating working state, so that the control valve supplies pulse fluid medium externally, at the same time, the return on-off control switch in the same flow path with the flow supply on-off control switch makes the return medium inlet passage continuously in the on and off alternating working state or continuously in the on state, so that the return medium cavity receives the returned fluid medium.

[0035] Further selectively making the driving unit be a driving motor, the flow supply on-off control switch be a first rotating body with a first passage, during operation, the first rotating body is driven by the driving motor and rotates at a set speed, when the first rotating body rotates to a set angle range, the first passage makes the flow supply medium discharge passage controlled thereby be in the on state;

[0036] The return on-off control switch is a second rotating body with a second passage, during operation, the second rotating body is driven by the driving motor and rotates at a set speed, when the second rotating body rotates to a set angle range, the second passage makes the return medium inlet passage controlled thereby be in the on state;

[0037] The first rotating body of the flow supply on-off control switch and the second rotating body of the return on-off control switch in the same flow path are coaxially arranged and driven by the same driving motor, or the first rotating body of the flow supply on-off control switch and the second rotating body of the return on-off control switch in the same flow path are non-linkage arranged and driven by different driving motors.

[0038] Further selectively select to make the driving motor be a servo motor or a step motor, the fluid control device further comprises an electric control unit, the driving motor is electrically connected with the electric control unit to control the frequency of the supply flow on-off control switch connecting the supply flow medium discharge channel; or, selectively make the driving motor be a servo motor or a step motor, the fluid control device further comprises an electric control unit, the driving motor is electrically connected with the electric control unit to control the frequency of the supply flow on-off control switch connecting the supply flow medium discharge channel and the frequency of the return flow on-off control switch connecting the return flow medium inlet channel.

[0039] Further selectively select to make the fluid control device further comprise an energy storage unit, the energy storage unit is connected with the supply flow medium cavity to make the supply flow medium cavity be in a set pressure range, the supply flow medium cavity and the return flow medium cavity in the same flow path are connected through a one-way control switch with a set opening pressure, when the pressure in the supply flow medium cavity is greater than the set opening pressure, the supply flow medium cavity and the return flow medium cavity are in the on state; or, selectively make the fluid control device further comprise an energy storage unit, the energy storage unit is connected with the supply flow medium cavity to make the supply flow medium cavity be in a set pressure range, the supply flow medium cavity and the return flow medium cavity are connected through an electromagnetic proportional overflow valve with an adjustable opening pressure, when the pressure in the supply flow medium cavity is greater than the set opening pressure, the supply flow medium cavity and the return flow medium cavity are in the on state.

[0040] Further selectively select to make the supply flow medium cavity be an ellipsoidal cavity or a spherical cavity, when the supply flow medium cavity is an ellipsoidal cavity, the connection interface of the energy storage unit and the supply flow medium cavity is arranged at the valve body opposite the focal point of the cross section of the supply flow medium cavity; when the supply flow medium cavity is a spherical cavity, the connection interface of the energy storage unit and the supply flow medium cavity is arranged at the valve body opposite the center of the supply flow medium cavity. Further reduce the hydraulic impact caused by the rapid on-off of the supply flow on-off control switch or the hydraulic pulsation caused by the pumping unit to the system, so that the supply flow medium cavity can maintain a relatively stable working pressure, so as to better meet the requirements of providing stable pressure pulse flow.

[0041] Further selectively, the fluid connection pipeline between the pumping unit and the supply medium cavity is arranged at the valve body opposite the focus of the cross section of the supply medium cavity; when the supply medium cavity is a spherical cavity, the fluid connection pipeline between the pumping unit and the supply medium cavity is arranged at the valve body opposite the center of the sphere of the supply medium cavity. The hydraulic impact caused by the quick on-off of the supply on-off control switch or the hydraulic pulse caused by the pumping unit can be reduced, and the supply medium cavity can maintain a stable working pressure, so as to better meet the requirement of providing pulse flow with stable pressure.

[0042] Further selectively, the return medium cavity is spherical or ellipsoidal, so as to eliminate the large impact on the hydraulic circuit caused by the air release when the negative pressure occurs.

[0043] The application further discloses a control system of the fluid control device, and the control system comprises a fluid medium source, a pumping unit and an execution element.

[0044] The fluid medium source is communicated with the supply medium cavity on the valve body through the pumping unit to supply fluid to the supply medium cavity.

[0045] The supply medium cavity is connected with the first medium inlet and outlet of the execution element, so that the supply medium cavity can provide the required fluid medium to the execution element connected therewith.

[0046] The return medium cavity is connected with the second medium inlet and outlet of the execution element, so that the return medium cavity can receive the returned fluid medium.

[0047] The return medium discharge channel of the return medium cavity arranged on the valve body is communicated with the fluid medium source through the negative pressure generating device.

[0048] In the application, those skilled in the art are motivated to arrange necessary components, units or systems according to the known technology in the related field.

[0049] In the application, the control system refers to a system using fluid medium as medium and capable of implementing control, such as a hydraulic control system or a pneumatic control system used in engineering machinery.

[0050] In the application, the fluid medium is not limited, and can be liquid medium or gas medium. In the specific implementation, the liquid medium is preferably hydraulic oil.

[0051] The fluid control device and the control system comprising the same can bring the following advantages

[0052] Advantages:

[0053] 1. The control valve can replace the multi-way valve of the existing control system and overcome many defects of the traditional multi-way valve. In addition, the control valve can discretize and meter the fluid medium, realize the digitization and intelligentization of the control system, and thus provide technical support and foundation for intelligent control of the control system.

[0054] 2. To eliminate the hydraulic impact and pressure pulsation caused by the discretization of the fluid medium, the supply medium cavity is provided in an ellipsoidal shape or a spherical shape, and the connection interface of the pipeline or energy storage unit of the pumping unit supplying the fluid medium with the supply medium cavity is arranged at the center of the sphere of the supply medium cavity or the focus of the ellipsoidal cavity, thereby improving the hydraulic impact caused by the rapid shutdown of the pumping unit or the supply flow control switch, keeping the supply medium cavity in the control valve at a relatively stable working pressure, and thus providing the system with pulse flow of stable pressure.

[0055] 3. The negative pressure generating device is arranged, and the fluid medium in the return medium cavity can be sucked out under the suction of the negative pressure generating device. In addition, the fluid medium on one side of the actuator (especially the hydraulic oil cylinder) needs to be squeezed out from the inside under certain working conditions. The fluid medium can be sucked out from the inside of the actuator by the negative pressure generating device, thereby effectively enhancing the load resistance of the actuator, improving the working efficiency, reducing the output power of the power source, and achieving better energy-saving effect. BRIEF DESCRIPTION OF DRAWINGS

[0056] The accompanying drawings, which are included to provide a further understanding of the present application, form a part of the present application and illustrate the illustrative embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0057] Figure 1 A structure schematic view of a fluid control device provided by the embodiments of the present application;

[0058] Figure 2 A structure schematic view of another fluid control device provided by the embodiments of the present application;

[0059] Figure 3 A structure schematic view of another fluid control device provided by the embodiments of the present application; Figure 2 A partial enlarged view of the structure of A in FIG. 8.

[0060] Wherein,

[0061] 1 valve body, 11 supply medium cavity, 12 return medium cavity, 13 supply medium inlet channel, 14 supply medium outlet channel, 15 return medium inlet channel, 16 return medium outlet channel, 17 supply flow control switch, 171 first rotating body, 18 return flow control switch, 181 second rotating body,

[0062] 2 drive motor,

[0063] 3 energy storage unit,

[0064] 4 negative pressure generating device, 41 cylinder body, 42 piston, 43 first cavity, 44 first medium inlet, 45 first medium outlet, 46 first switch unit, 47 second cavity, 48 second medium inlet, 49 second medium outlet, 50 third switch unit, 501 first one-way switch, 502 second one-way switch, 51 second switch unit,

[0065] 5 fluid medium source. DETAILED DESCRIPTION

[0066] In order to more clearly illustrate the overall concept of the present application, the following will be described in detail with reference to the accompanying drawings.

[0067] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0068] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0069] In the present application, unless specifically defined and limited otherwise, the terms "mounting", "connected", "connection", "fixed", and the like, should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection, and can also be communication; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0070] In the present application, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. In the description of the specification, the description of the terms "one scheme", "some schemes", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the scheme or example are included in at least one scheme or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same scheme or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more schemes or examples in a suitable manner.

[0071] For the convenience of description, "front", "back", "left", "right", "up", "down" in the following are relative to the user when using the control valve.

[0072] In the present application, the "supply medium cavity and return medium cavity constituting the same flow path" means that the supply medium cavity and the return medium cavity are both parts of the same fluid circuit, that is, the supply medium cavity and the return medium cavity are at least connected to the same actuator and constitute the same fluid circuit.

[0073] In the present application, a value above includes the number, for example, two or more includes two.

[0074] As Figure 1 A fluid control device as shown in the figure, comprising a control valve, the control valve comprising a valve body 1, the valve body 1 is provided with a supply medium cavity 11 and a return medium cavity 12 inside, the valve body 1 is provided with a supply medium inlet channel 13 and a supply medium outlet channel 14 communicating with the supply medium cavity 11, the valve body 1 is provided with a return medium inlet channel 15 and a return medium outlet channel 16 communicating with the return medium cavity 12;

[0075] The control valve further comprises a supply flow on-off control switch 17 and a return flow on-off control switch 18, the supply flow on-off control switch 17 controls the opening and closing of the supply flow medium discharge passage 14, and the return flow on-off control switch 18 controls the opening and closing of the return flow medium inlet passage 15;

[0076] When the supply flow on-off control switch 17 is connected to the supply flow medium discharge passage 14, the return flow on-off control switch 18 is connected or disconnected to the return flow medium inlet passage 15, the supply flow medium cavity 11 provides fluid medium for the actuator, and the return flow medium cavity 12 stores the returned fluid medium or provides space for the expansion of gas in the fluid medium; the supply flow on-off control switch 17 and the return flow on-off control switch 18 are respectively driven by the driving unit;

[0077] The fluid control device further comprises a negative pressure generating device 4, and the return flow medium cavity 12 is connected to the negative pressure generating device 4; in a specific working process, when the negative pressure generating device 4 is in a negative pressure forming state, the fluid in the return flow medium cavity 12 flows out, when the negative pressure generating device 4 is in a positive pressure forming state, the fluid in the return flow medium cavity 12 is blocked, and when the negative pressure generating device 4 is in a non-working state, the negative pressure generating device 4 serves as a passage for the fluid medium in the return flow medium cavity 12 to flow out. When the fluid control device is applied to a control system, the fluid medium source 5 can be selectively connected to the supply flow medium cavity 11 through the pumping unit and the supply flow medium inlet passage 13, the supply flow medium cavity 11 is connected to one fluid medium inlet and outlet end of the actuator through the supply flow medium discharge passage 14 and the reversing valve, the other fluid medium inlet and outlet end of the actuator is connected to the return flow medium cavity 12 through the reversing valve and the return flow medium inlet passage 15, and the return flow medium cavity 12 is directly or indirectly connected to the fluid medium source 5 through the return flow medium discharge passage 16. It should be noted that when the supply flow on-off control switch 17 is connected to the supply flow medium discharge passage 14, the return flow medium cavity 12 stores the returned fluid medium in a normal working condition, and in some special working conditions, the return flow on-off control switch 18 in the same flow path is in a disconnected state. As a variable embodiment, one supply flow medium cavity 11 in the present application can be selectively connected to one or more actuators (which can be selectively set as pneumatic actuators or hydraulic actuators, for example, fluid motors, air cylinders or hydraulic cylinders, etc.), and the specific number can be selected according to the number of actuators provided in the control system where the fluid control device is located, for example, the control valve is connected to one, two, three, four, five, six or more actuators.

[0078] It should be noted that the negative pressure generating device described in the present application is not specifically limited, and it can be any device capable of forming negative pressure and promoting the flow of fluid medium in the backflow medium container 12 from the backflow medium discharge channel 16. It can be a vacuum pump, a driven cylinder piston mechanism, etc.

[0079] As a convertible embodiment, the control valve can selectively provide two or more flow medium containers 11 and one or more backflow medium containers 12 on the valve body 1. In addition, in specific implementation, the control valve including one flow medium container 11 and one backflow medium container 12 can be selectively used as a control valve unit, and two or more control valve units can be combined together as a multi-way valve of a control system according to actual needs. The control system can be further selectively set as a hydraulic control system or a pneumatic system, and is preferably set as a control system using hydraulic oil as the fluid medium. The control valve described in the present application is provided with a control switch on the flow medium discharge channel 14 and the backflow medium inlet channel 15, respectively, and can control the opening and closing of the respective controlled channels, so that the control valve can provide fluid medium according to the demand of the actuator. At the same time, the multiple actuators of the control system including the control valve can be independent of each other, avoiding the mutual coupling, mutual restriction and mutual influence between the actuators of the traditional control system.

[0080] As a preferred embodiment of the present embodiment, the negative pressure generating device is further selectively provided as a cylinder piston mechanism, which includes a cylinder 41 and a piston 42. In specific implementation, the piston 42 and the cylinder 41 form a first container 43 with variable volume, and the cylinder 41 is provided with a first medium inlet 44 and a first medium outlet 45 communicating with the first container 43.

[0081] The backflow medium container 12 is connected to the first medium inlet 44 through the backflow medium discharge channel 16, and a first switch unit 46 for controlling the opening and closing of the backflow medium discharge channel is provided on the backflow medium discharge channel 16. A second switch unit 51 is provided on the fluid channel at or downstream of the first medium outlet 45.

[0082] When the volume of the first container 43 increases, the first switch unit 46 on the backflow medium discharge channel 16 in the working flow path is in an open state, and the second switch unit 51 is in a closed state, so that the fluid in the backflow medium container 12 flows into the first container 43.

[0083] When the volume of the first chamber 43 decreases, the first switch unit 46 on the reflux medium discharge channel on the working flow path is in the off state, and the second switch unit 51 is in the on state, so that the fluid flowing into the first chamber 43 flows out to a specified position through the first medium outlet 45. In specific implementation, the fluid medium can be selectively squeezed into the fluid medium source; in addition, the first switch unit 46 and the second switch unit 51 can be further selectively set as a controlled valve or a one-way valve that opens in a set direction. When the negative pressure generating device is not working, the first medium inlet 44 and the first medium outlet 45 are in a connected state, so that the first chamber 43 serves as a passage for discharging the fluid medium in the reflux medium chamber 12. In specific implementation, the first medium outlet 45 can be further connected to the fluid medium source, and the second switch unit 51 can be set on the fluid channel connecting the first medium outlet 45 and the fluid medium source.

[0084] In the specific implementation of the present application, the valve body 1 may be selectively provided with two or more supply medium cavities 11 and at least two return medium cavities 12, each of the supply medium cavities 11 and the two or more return medium cavities 12 being adapted to each other and serving as components of the same flow path; each of the supply medium cavities 11 is respectively communicated with a supply medium inlet channel 13 and at least one supply medium outlet channel 14 provided on the valve body 1, and a supply flow cut-off control switch 17 is provided on each of the supply medium outlet channels 14; each of the return medium cavities 12 is respectively communicated with at least one return medium inlet channel 15 and a return medium outlet channel 16 provided on the valve body 1, and a return flow cut-off control switch 18 is provided on each of the return medium inlet channels 15; when the supply flow cut-off control switch 17 is in operation, the valve body 1 may be provided with a plurality of return medium cavities 11 and a plurality of return medium cavities 12. 7 is in the open state, the reflux interruption control switch 18 in the same flow path is in the open or closed state, the supply medium chamber 11 provides fluid medium to the actuator, and the reflux medium chamber 12 accommodates the reflux fluid medium or provides space for the expansion of the gas in the fluid medium; the supply interruption control switch 17 and the reflux interruption control switch 18 are driven by the driving unit; the reflux medium chamber 12 provided on the valve body 1 is respectively connected to the negative pressure generating device 4, when the negative pressure generating device 4 is in a working condition of forming negative pressure, the fluid medium in the reflux medium chamber 12 connected to the negative pressure generating device 4 flows out; when the negative pressure generating device 4 is in a working condition of forming positive pressure, the fluid in the reflux medium chamber 12 is blocked; when the negative pressure generating device 4 is in a non-working condition, the negative pressure generating device 4 serves as a passage for the discharge fluid in the reflux medium chamber 12.

[0085] In actual application, the control system often contains multiple execution elements, for which the fluid control device needs to be able to match multiple execution elements at the same time; the present application can achieve one-to-many function by a group of the supply medium cavity 11 and the return medium cavity 12 in the same flow path; in addition, from the control strategy, the fluid control device can also selectively include multiple groups of the supply medium cavity 11 and the return medium cavity 12 to match one or more execution elements.

[0086] It is worth noting that in the normal working process of the existing hydraulic cylinder, the piston needs to extrude the fluid medium inside the second side when running from the first side to the second side, and a large loss will be generated in the extrusion process. Moreover, this working condition occurs frequently, which puts higher requirements on the performance of the power unit (engine, etc.) (such as power requirements), so a larger power unit is needed to match, thereby increasing the investment cost of the equipment. In addition, the frequent working condition of the power unit also increases a large amount of energy consumption cost and equipment maintenance cost. The present application sets a negative pressure generating device, under the suction action of the negative pressure generating device, the fluid medium in the return medium cavity can be sucked out, thereby effectively enhancing the working capacity of the execution element against load, recovering useless power, and reducing the output power of the power unit, achieving better energy saving, consumption reduction and cost reduction effect.

[0087] As the preferred embodiment of the present application, when the embodiment of two or more flow medium cavities 11 and at least one return medium cavity 12 are provided inside the valve body 1, the negative pressure generating device can be further selectively provided as a cylinder-piston mechanism, which includes a cylinder 41 and a piston 42, the piston 42 and the cylinder 41 form a first cavity 43 and a second cavity 47 with variable volume, the cylinder 41 is provided with a first medium inlet 44 and a first medium outlet 45 communicating with the first cavity 43, and a second medium inlet 48 and a second medium outlet 49 communicating with the second cavity 47; each of part of the return medium cavities 12 is communicated with the first cavity 43 through a return medium discharge channel 16, a first medium inlet 44, and the rest of the return medium cavities 12 is communicated with the second cavity 47 through a return medium discharge channel 16, a second medium inlet 48, respectively, and a first switch unit 46 is arranged on each return medium discharge channel 16, the return medium cavities 12 communicated with the first cavity 43 are communicated with at least one of the return medium cavities 12 communicated with the second cavity 47 through a third switch unit 50, and a second switch unit 51 is arranged on the fluid channel at or downstream of the first medium outlet 45 and the fluid channel at or downstream of the second medium outlet 49, respectively; in the specific work, when the volume of the first cavity 43 increases, the first switch unit 46 on the return medium discharge channel 16 in the working flow path and connected with the first cavity 43 is in the open state, and the second switch unit 51 associated with the first cavity 43 is in the off state; when the volume of the first cavity 43 decreases, the first switch unit 46 on the return medium discharge channel 16 in the working flow path and connected with the first cavity 43 is in the off state, and the second switch unit 51 associated with the first cavity 43 is in the open state; when the volume of the second cavity increases, the first switch unit 46 on the return medium discharge channel 16 in the working flow path and connected with the second cavity 47 is in the open state, and the second switch unit 51 associated with the second cavity 47 is in the off state; when the volume of the second cavity 47 decreases, the first switch unit 46 on the return medium discharge channel 16 in the working flow path and connected with the second cavity 47 is in the off state, and the second switch unit 51 associated with the second cavity 47 is in the open state; when the pressure difference in the return medium cavities connected by the third switch unit 50 is below the set value, the third switch unit 50 is in the off state, and when the pressure difference in the return medium cavities connected by the third switch unit 50 is above the set value, the third switch unit 50 is in the on state.In the foregoing embodiment, in the reciprocating movement of the piston 42, when the flow paths of the backflow medium cavities 12 communicating with the first cavity 43 are all in a non-working state and at least part of the flow paths of the backflow medium cavities 12 communicating with the second cavity 47 are in a working state, the third switch unit 50 communicating with the backflow medium cavity 12 in the working state is in an open state, so that the backflow medium cavity 12 communicating with the second cavity 47 and in the working state supplies fluid medium to the first cavity 43, to avoid the first cavity 43 from being vacuumized; when the flow paths of the backflow medium cavities 12 communicating with the second cavity 47 are all in a non-working state and at least part of the flow paths of the backflow medium cavities 12 communicating with the first cavity 43 are in a working state, the third switch unit 50 communicating with the backflow medium cavity 12 in the working state is in an open state, so that the backflow medium cavity 12 communicating with the first cavity 43 and in the working state supplies fluid medium to the second cavity 47, to avoid the second cavity 47 from being vacuumized. In addition, in the reciprocating movement of the piston 42, when the fluid medium flowing into the backflow medium cavity is expanded in gas-liquid separation and the pressure difference between the two backflow medium cavities is greater than the opening pressure of the third switch unit 50, the third switch unit 50 is in a connected state, to release pressure energy and reduce the impact caused by gas-liquid separation, so that the fluid control device can work more stably.

[0088] In the reciprocating movement of the piston 42, the cylinder-piston mechanism can continuously suck the fluid medium in the backflow medium cavity 12 in the working state into the first cavity 43 and the second cavity 47; in the specific implementation, the first switch unit 46 can be further selectively set as an electric control valve or a one-way valve, preferably a one-way valve; as a convertible embodiment, the third switch unit 50 can be further selectively set as an electric control valve. It should be noted that, in order to avoid confusion, the applicant defines the switch units arranged on the backflow medium discharge channels 16 as first switch units, and the number of the first switch units 46 should be selectively matched according to the number of the backflow medium cavities 12 included in the fluid control device, and one first switch unit 46 can be arranged on the backflow medium discharge channel 16 of each backflow medium cavity 12.

[0089] As a preferred embodiment of the present application, as Figure 2As shown, further selectively provided on the valve body 1 are two flow medium cavities 11 and two return medium cavities 12, wherein one flow medium cavity 11 and one return medium cavity 12 are adapted to be part of the same flow path, and the other flow medium cavity 11 and the other return medium cavity 12 are adapted to be part of the same flow path; each flow medium cavity 11 is in communication with at least one flow medium outlet channel 14 (the number of flow medium outlet channels 14 depends on the number of actuators and the specific design requirements of the control system applied), and each return medium cavity 12 is in communication with at least one return medium inlet channel 15 (the number of flow medium outlet channels 14 depends on the number of actuators and the specific design requirements of the control system applied); one of the return medium cavities 12 is in communication with the first medium inlet 44 of the first cavity 43 via a first switching unit 46, and the other return medium cavity 12 is in communication with the first medium inlet 44 of the second cavity 47 via another first switching unit 46; the two return medium cavities 12 are in communication with each other via the third switching unit 50; in specific operation, when the volume of the first cavity 43 increases and the flow path in which the return medium cavity 12 connected to the first cavity 43 is in operation, the fluid medium in the return medium cavity 12 connected to the first cavity 43 flows into the first cavity 43 via the first switching unit 46 on the communication channel between them; when the volume of the second cavity 47 increases and the flow path in which the return medium cavity 12 connected to the second cavity 47 is in operation, the fluid in the return medium cavity 12 connected to the second cavity 47 flows into the second cavity 47 via the first switching unit 46 on the communication channel between them; when the flow paths in which the return medium cavities 12 connected to the first cavity 43 are all in a non-operating state and the flow path in which the return medium cavity 12 connected to the second cavity 47 is in an operating state, if the pressure difference between the return medium cavities connected by the third switching unit 50 is greater than the set opening pressure, the third switching unit 50 is in an open state to enable the return medium cavity 12 connected to the second cavity 47 and in an operating state to provide fluid medium to the first cavity 43; when the flow path in which the return medium cavity 12 connected to the second cavity 47 is in a non-operating state and the flow path in which the return medium cavity 12 connected to the first cavity 43 is in an operating state, if the pressure difference between the return medium cavities connected by the third switching unit 50 is greater than the set opening pressure, the third switching unit 50 is in an open state to enable the return medium cavity 12 connected to the first cavity 43 and in an operating state to provide fluid medium to the second cavity 47.

[0090] As a preferred embodiment of the present application, all the aforementioned embodiments, examples and their alternative embodiments of the present application can further selectively drive the cylinder piston mechanism by a reciprocating driving mechanism to make the piston 42 reciprocate in the cylinder 41, as shown in Figure 3 As shown, the third switch unit 50 comprises a first one-way switch 501 and a second one-way switch 502 arranged in parallel, the on direction of the first one-way switch 501 is arranged opposite to the on direction of the second one-way switch 502, when the piston 42 reciprocates, the first one-way switch 501 and the second one-way switch 502 are selectively opened to make the piston 42 of the cylinder piston mechanism obtain fluid medium from the reflux medium cavity 12 connected therewith during reciprocation; as an alternative embodiment, the cylinder piston mechanism can be selectively driven by a reciprocating driving mechanism to make the piston 42 reciprocate in the cylinder 41, the third switch unit 50 is arranged as a controlled switch, when the piston 42 reciprocates, the controlled switch is selectively opened to make the piston 42 of the cylinder piston mechanism obtain fluid medium from the reflux medium cavity 12 connected therewith during reciprocation and keep the vacuum degree in the reflux medium cavity connected therewith within a set range. In specific implementation, the reciprocating driving mechanism is arranged as a driving mechanism comprising a gear and a rack, the gear is driven by a driving motor or a hydraulic motor to reciprocate, the rack reciprocates under the drive of the gear; in specific implementation, when the reciprocating driving mechanism is limited by the vacuum degree in the first cavity 43 and the second cavity 47, the driving motor or the hydraulic motor of the reciprocating driving mechanism stops working when the vacuum degree in the first cavity 43 and the second cavity 47 is greater than a set value.

[0091] As a preferred embodiment of the present application, all the aforementioned embodiments, examples and alternative embodiments of the present application can further selectively make the fluid control device work in such a way that the supply flow on-off control switch 17 makes the supply flow medium discharge passage 14 continuously work in an alternating on-off state to make the control valve supply pulsed fluid medium to the outside; as an alternative embodiment, it can also selectively make the fluid control device work in such a way that the supply flow on-off control switch 17 makes the supply flow medium discharge passage 14 continuously work in an alternating on-off state to make the control valve supply pulsed fluid medium to the outside, while the return flow on-off control switch 18 in the same flow path as the supply flow on-off control switch 17 makes the return flow medium inlet passage 15 continuously work in an alternating on-off state or a continuously on state to make the return flow medium cavity 12 receive the return flow of fluid medium. By making the supply flow on-off control switch 17 frequently work in an open or off state under the driving of the driving unit, the control valve can provide pulsed fluid medium to the actuator, implement metering and segmented supply of fluid medium, thus realizing discretization and digitization of fluid medium supply, combining with electronic control technology to provide technical support for the intelligence of the fluid control system using the control valve.

[0092] As a preferred embodiment of the present application, all the aforementioned embodiments, examples and alternative embodiments of the present application can further selectively make the driving unit be a driving motor 2, and the supply flow on-off control switch 17 be a first rotating body 171 with a first passage, which, when working, is driven by the driving motor 2 and rotates at a set speed; when the first rotating body 171 rotates to a set angle range, the first passage makes the supply flow medium discharge passage 14 it controls be in an on state;

[0093] The return flow on-off control switch 18 is a second rotating body 181 with a second passage, which, when working, is driven by the driving motor 2 and rotates at a set speed; when the second rotating body 181 rotates to a set angle range, the second passage makes the return flow medium inlet passage 15 it controls be in an on state;

[0094] The first rotating body 171 of the supply flow on-off control switch 17 and the second rotating body 181 of the return flow on-off control switch 18 in the same flow path are coaxially arranged and driven by the same driving motor. As an alternative embodiment, the first rotating body 171 of the supply flow on-off control switch 17 and the second rotating body 181 of the return flow on-off control switch 18 in the same flow path can be arranged non-rotationally and driven by different driving motors. In a specific embodiment, the first rotating body 171 is further selectively arranged as a rotating shaft, and the first channel is further selectively arranged as a through hole penetrating the rotating shaft. The return flow on-off control switch 18 is further selectively arranged as a second rotating body 181 with a second channel. In operation, the second rotating body 181 is driven by the driving motor 2 and rotates at a set speed. When the second rotating body 181 rotates to a set angle range, the second channel is in an on state, allowing the return medium controlled by the second channel to enter the passage 15. In a specific embodiment, the second rotating body 181 is further selectively arranged as a rotating shaft, and the second channel is further selectively arranged as a through hole penetrating the rotating shaft. As an alternative embodiment, the first rotating body 171 of the supply flow on-off control switch 17 and the second rotating body 181 of the return flow on-off control switch 18 in the same flow path can be coaxially arranged and driven by the same driving motor 2, or arranged non-rotationally and driven by different driving motors 2 (not shown).

[0095] As a preferred embodiment of the present application, all the aforementioned embodiments of the present application containing the driving motor 2 can further selectively arrange the driving motor 2 as a servo motor, and the fluid control device further comprises an electronic control unit, and the driving motor 2 is electrically connected to the electronic control unit to control the frequency of the supply flow on-off control switch 17 opening the supply medium discharge passage 14. As an alternative embodiment, the driving motor 2 can be selectively arranged as a servo motor, and the fluid control device further comprises an electronic control unit, and the driving motor 2 is electrically connected to the electronic control unit to control the frequency of the supply flow on-off control switch 17 opening the supply medium discharge passage 14 and the frequency of the return flow on-off control switch 18 opening the return medium inlet passage 15. As an alternative embodiment, in a specific embodiment, the driving motor 2 can be selectively arranged as a stepping motor. In a specific embodiment, since the speed and angle of the driving motor 2 can be accurately controlled, the amount of fluid medium supplied by the supply medium cavity 11 can be indirectly and accurately calculated, and by combining the control unit, the execution element can be accurately provided with fluid medium, and by discretizing and digitizing the supplied fluid medium, the intelligence of the control can be further improved.

[0096] As an embodiment of the present application, all the foregoing embodiments of the present application can further selectively make the fluid control device further comprise an energy storage unit 3, the energy storage unit 3 is connected with the supply medium cavity 11 to make the supply medium cavity 11 in a set pressure range, the supply medium cavity 11 and the return medium cavity 12 in the same flow path are communicated through a one-way control switch with a set opening pressure, when the pressure in the supply medium cavity 11 is greater than the set opening pressure, the supply medium cavity 11 and the return medium cavity 12 are in the on state. As a convertible embodiment, it can also selectively make the energy storage unit 3 connected with the supply medium cavity 11 to make the supply medium cavity 11 in a set pressure range, the supply medium cavity 11 and the return medium cavity 12 are communicated through an electromagnetic proportional overflow valve with an adjustable opening pressure, when the pressure in the supply medium cavity 11 is greater than the set opening pressure, the supply medium cavity 11 and the return medium cavity 12 are in the on state. By providing the energy storage unit 3, the present application can make the supply medium cavity 11 in a set pressure range, thereby making the fluid circuit more stable during operation. In addition, the present application can also achieve the same technical effect by providing the one-way control switch, and in specific implementation, the one-way control switch can be selectively set as a one-way valve.

[0097] As a preferred embodiment of the present application, all the foregoing embodiments of the present application and their convertible embodiments can further selectively make the supply medium cavity 11 be an ellipsoidal cavity or a spherical cavity; and / or, selectively make the return medium cavity 12 be an ellipsoidal cavity or a spherical cavity. In specific implementation, when the supply medium cavity 11 is an ellipsoidal cavity, it is further preferred to make the connection interface of the energy storage unit 3 with the supply medium cavity 11 be provided at the valve body opposite the focus of the central cross-sectional ellipse of the supply medium cavity 11; when the supply medium cavity 11 is a spherical cavity, it is preferred to make the connection interface of the energy storage unit 3 with the supply medium cavity 11 be provided at the valve body opposite the center of the sphere of the supply medium cavity 11. Further reduce the hydraulic impact caused by the rapid on-off of the supply flow control switch 71 or the hydraulic pulsation caused by the pumping unit to the system, so that the supply medium cavity 11 can maintain a relatively stable working pressure, so as to better meet the requirement of providing stable pressure pulse flow.

[0098] In the specific implementation, the fluid connection pipeline between the pumping unit and the supply medium cavity 11 can be further selectively arranged at the valve body opposite the focal point of the central cross-section ellipse of the supply medium cavity 11, and when the supply medium cavity 11 is a spherical cavity, the fluid connection pipeline between the pumping unit and the supply medium cavity can be arranged at the valve body opposite the center of the sphere of the supply medium cavity 11. The hydraulic impact caused by the rapid on-off of the supply flow control switch 71 or the hydraulic pulsation caused by the pumping unit can be reduced, the working pressure of the supply medium cavity can be kept stable, and the requirement of the pulse flow with stable pressure can be better met.

[0099] In the specific implementation, the return medium cavity 12 can be further selectively arranged in a spherical or ellipsoidal shape to eliminate the large impact on the hydraulic circuit caused by the air release when the negative pressure occurs.

[0100] In order to further clarify the fluid control device disclosed in the present application, the control system to which the fluid control device is applied is described as follows:

[0101] A control system of a fluid control device, the control system comprising a fluid medium source, a pumping unit and an execution element, the execution element being provided as one or more, each execution element comprising a first medium inlet and outlet and a second medium inlet and outlet; the fluid medium source being in communication with a supply medium cavity 11 on the valve body 1 via the pumping unit to supply fluid thereto, the supply medium cavity 11 being coupled to the first medium inlet and outlet of at least one execution element to enable the supply medium cavity 11 to provide the required fluid medium to the execution element coupled thereto; a return medium cavity 12 being coupled to the second medium inlet and outlet of at least one execution element to enable the return medium cavity 12 to receive the returned fluid medium; the return medium discharge passage 16 of the return medium cavity 12 provided on the valve body 1 being in communication with the fluid medium source via the negative pressure generating device. As alternative embodiments, in specific implementation, the control system of the fluid control device can further be selectively provided with one, two, three, four, five or more than five supply medium cavities 11, and further be selectively provided with one, two, three, four, five or more than five return medium cavities 12, and each execution element is coupled to one supply medium cavity 11 and one return medium cavity 12 to form as many working flow paths as the number of execution elements, and preferably as many supply medium discharge passages 14 as the number of execution elements are provided on the valve body 1, each execution element being coupled to one supply medium discharge passage 14 to enable the execution elements to work independently of each other and not to be interfered by the remaining execution elements. In specific operation, the pumping unit pumps the fluid medium from the fluid medium source to the supply medium cavity 11, and the execution element is provided with the fluid medium by controlling the supply flow control switch 17 provided on the supply medium discharge passage 14, and during the operation of the execution element, the fluid medium discharged from the execution element enters the return medium cavity 12, and under the action of the negative pressure generating device, the fluid medium in the return medium cavity 12 is pumped out to the fluid medium source for next use. In specific implementation, the control system can selectively comprise one or more fluid medium sources. In specific implementation, the control system is further selectively provided as the control system of a construction machine (such as a excavator, a truck crane, etc.), and the execution element comprises a telescopic cylinder, a hydraulic motor.

[0102] In the present application, the "negative pressure generating device in the negative pressure forming condition" refers to the condition that the fluid medium in the return medium cavity coupled to the negative pressure generating device is discharged from the return medium discharge passage, for example, in the aforementioned embodiment comprising the first cavity, when the fluid medium in the return medium cavity is flowed into the first cavity from the return medium discharge passage during the volume increasing process of the first cavity, the condition is that the negative pressure generating device is in the negative pressure forming condition.

[0103] In the present application, the so-called "negative pressure generating device is in the working condition of forming positive pressure" refers to the working condition that the fluid medium in the backflow medium cavity connected with the generating device cannot be discharged from the backflow medium discharge channel, for example, in the aforementioned embodiment comprising the first cavity, when the first cavity is in the volume reduction process, the working condition that the fluid medium in the backflow medium cavity cannot flow into the first cavity from the backflow medium discharge channel is the working condition that the negative pressure generating device is in the working condition of forming positive pressure, that is, the working condition that the fluid in the backflow medium cavity is in the blocked state.

[0104] The drawings of the present application are only a schematic, and any technical solution meeting the description of the present application belongs to the protection scope of the present application.

[0105] Each embodiment in the present specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly explains the difference from other embodiments. Especially, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the related parts can be referred to the part of the method embodiment.

[0106] The above is only an embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A fluid control device, characterized in that, a control valve is provided, the control valve comprises a valve body, the valve body is internally provided with a supply medium cavity and a return medium cavity, the valve body is provided with a supply medium inlet channel and a supply medium outlet channel which are connected to the supply medium cavity, the valve body is provided with a return medium inlet channel and a return medium outlet channel which are connected to the return medium cavity; the control valve further comprises a supply flow on-off control switch and a return flow on-off control switch, the supply flow on-off control switch controls the opening and closing of the supply medium outlet channel, and the return flow on-off control switch controls the opening and closing of the return medium inlet channel; the supply medium cavity provides fluid medium for an actuator, and the return medium cavity stores the returned fluid medium; the supply flow on-off control switch and the return flow on-off control switch are driven by a driving unit; the fluid control device further comprises a negative pressure generating device, the return medium cavity is connected to the negative pressure generating device, when the negative pressure generating device is in a working condition of forming negative pressure, the fluid in the return medium cavity flows out, and when the negative pressure generating device is in a non-working condition, the negative pressure generating device serves as a passage for the fluid medium in the return medium cavity to flow out.

2. The fluid control device according to claim 1, characterized in that, the negative pressure generating device is a cylinder-piston mechanism, the cylinder-piston mechanism comprises a cylinder and a piston, the piston and the cylinder form a first cavity with variable volume, the cylinder is provided with a first medium inlet and a first medium outlet which are connected to the first cavity; the return medium cavity is connected to the first medium inlet through the return medium outlet channel, a first switch unit for controlling the opening and closing of the return medium outlet channel is arranged on the return medium outlet channel, and a second switch unit is arranged on the fluid channel downstream of the first medium outlet; when the volume of the first cavity increases, the first switch unit on the return medium outlet channel in the working flow path is in an open state, and the second switch unit is in a closed state; when the volume of the first cavity decreases, the first switch unit on the return medium outlet channel in the working flow path is in a closed state, and the second switch unit is in an open state.

3. A fluid control device, characterized in that, a control valve is provided, the control valve comprises a valve body, the valve body is internally provided with two or more supply medium cavities and at least two return medium cavities, each of the supply medium cavities and two or more of the return medium cavities are adapted and serve as components of the same flow path; each of the supply medium cavities is connected to a supply medium inlet channel arranged on the valve body and at least one supply medium outlet channel arranged on the valve body, and a supply flow on-off control switch is arranged on each of the supply medium outlet channels; each of the return medium cavities is connected to at least one return medium inlet channel arranged on the valve body and a return medium outlet channel arranged on the valve body, and a return flow on-off control switch is arranged on each of the return medium inlet channels. The supply medium cavity provides fluid medium for the execution element, and the return medium cavity stores the returned fluid medium; the supply flow control switch and the return flow control switch are driven by the driving unit; The fluid control device further comprises a negative pressure generating device, the return medium cavities are connected to the negative pressure generating device, the return medium cavities provided on the valve body are respectively connected to the negative pressure generating device, when the negative pressure generating device is in a working condition of forming negative pressure, the fluid in the return medium cavities flows out; when the negative pressure generating device is in a non-working condition, the negative pressure generating device serves as a passage for discharging the fluid in the return medium cavities.

4. The fluid control device according to claim 3, wherein The negative pressure generating device is a cylinder-piston mechanism, the cylinder-piston mechanism comprises a cylinder and a piston, the piston and the cylinder form a first cavity and a second cavity with variable volumes, the cylinder is provided with a first medium inlet and a first medium outlet connected to the first cavity and a second medium inlet and a second medium outlet connected to the second cavity; Each of part of the return medium cavities is connected to the first cavity through a return medium discharge channel and the first medium inlet, and each of the rest of the return medium cavities is connected to the second cavity through a return medium discharge channel and the second medium inlet, a first switch unit is arranged on each of the return medium discharge channels, the return medium cavities connected to the first cavity are connected to at least one of the return medium cavities connected to the second cavity through a third switch unit; A second switch unit is arranged on a fluid channel at or downstream of the first medium outlet and a fluid channel at or downstream of the second medium outlet; When the volume of the first cavity increases, the first switch unit on the return medium discharge channel in the working flow path and connected to the first cavity is in an open state, and the second switch unit connected to the first cavity is in a closed state; When the volume of the first cavity decreases, the first switch unit on the return medium discharge channel in the working flow path and connected to the first cavity is in a closed state, and the second switch unit connected to the first cavity is in an open state; When the volume of the second cavity increases, the first switch unit on the return medium discharge channel in the working flow path and connected to the second cavity is in an open state, and the second switch unit connected to the second cavity is in a closed state; When the volume of the second cavity decreases, the first switch unit on the return medium discharge channel in the working flow path and connected to the second cavity is in a closed state, and the second switch unit connected to the second cavity is in an open state; When the pressure difference in the return medium cavities connected by the third switch unit is below a set value, the third switch unit is in a closed state, and when the pressure difference in the return medium cavities connected by the third switch unit is above the set value, the third switch unit is in an open state.

5. The fluid control device according to claim 4, wherein The cylinder piston mechanism is driven by a reciprocating driving mechanism to reciprocate the piston in the cylinder, the third switch unit comprises a first one-way switch and a second one-way switch arranged in parallel, the on direction of the first one-way switch is arranged opposite to the on direction of the second one-way switch, when the piston reciprocates, the first one-way switch and the second one-way switch are selectively opened, so that the first cavity and the second cavity can obtain fluid medium from the backflow medium cavity connected therewith during the reciprocation of the piston.

6. The fluid control device according to any one of claims 1 to 5, wherein, in operation, the supply flow on-off control switch causes the supply flow medium discharge passage to be in an alternating on-off state, so that the control valve supplies pulse fluid medium to the outside; or, in operation, the supply flow on-off control switch causes the supply flow medium discharge passage to be in an alternating on-off state, so that the control valve supplies pulse fluid medium to the outside, and the backflow on-off control switch in the same flow path as the supply flow on-off control switch causes the backflow medium inlet passage to be in an alternating on-off state or a continuous on state, so that the backflow medium cavity receives backflow fluid medium.

7. The fluid control device according to claim 6, wherein, the driving unit is a driving motor, the supply flow on-off control switch is a first rotating body with a first passage, in operation, the first rotating body is driven by the driving motor to rotate at a set speed, when the first rotating body rotates to a set angle range, the first passage causes the supply flow medium discharge passage controlled thereby to be in an on state; the backflow on-off control switch is a second rotating body with a second passage, in operation, the second rotating body is driven by the driving motor to rotate at a set speed, when the second rotating body rotates to a set angle range, the second passage causes the backflow medium inlet passage controlled thereby to be in an on state; the first rotating body of the supply flow on-off control switch and the second rotating body of the backflow on-off control switch in the same flow path are coaxially arranged and driven by the same driving motor, or the first rotating body of the supply flow on-off control switch and the second rotating body of the backflow on-off control switch in the same flow path are non-linked arranged and driven by different driving motors.

8. The fluid control device according to claim 7, wherein, the driving motor is a servo motor or a stepping motor, the fluid control device further comprises an electronic control unit, the driving motor is electrically connected to the electronic control unit to control the frequency at which the supply flow on-off control switch opens the supply flow medium discharge passage; or, the driving motor is a servo motor or a stepping motor, the fluid control device further comprises an electronic control unit, the driving motor is electrically connected to the electronic control unit to control the frequency at which the supply flow on-off control switch opens the supply flow medium discharge passage, and to control the frequency at which the backflow on-off control switch opens the backflow medium inlet passage.

9. The fluid control device according to any one of claims 1 to 5 and 7 and 8, wherein the fluid control device further comprises an energy storage unit coupled to the supply medium chamber to maintain the supply medium chamber at a set pressure range, and the supply medium chamber and the return medium chamber in the same flow path are connected through a one-way control switch having a set opening pressure, and when the pressure in the supply medium chamber is greater than the set opening pressure, the supply medium chamber and the return medium chamber are in an on state; or, the fluid control device further comprises an energy storage unit coupled to the supply medium chamber to maintain the supply medium chamber at a set pressure range, and the supply medium chamber and the return medium chamber are connected through an electromagnetic proportional relief valve having an adjustable opening pressure, and when the pressure in the supply medium chamber is greater than the set opening pressure, the supply medium chamber and the return medium chamber are in an on state.

10. A control system using the fluid control device according to any one of claims 1 to 9, wherein the control system comprises a fluid medium source, a pumping unit, and an actuator, and the actuator is provided as one or more, and each actuator comprises a first medium inlet and outlet and a second medium inlet and outlet; the fluid medium source is connected to the supply medium chamber on the valve body through the pumping unit to supply fluid to the supply medium chamber, the supply medium chamber is coupled to the first medium inlet and outlet of at least one actuator to enable the supply medium chamber to provide the required fluid medium to the actuator connected thereto, the return medium chamber is coupled to the second medium inlet and outlet of at least one actuator to enable the return medium chamber to receive the returned fluid medium, and the return medium discharge passage of the return medium chamber provided on the valve body is connected to the fluid medium source through the negative pressure generating device. ​ ​ ​ ​ ​ ​ ​

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