CN113323933B - Differential pressure matching type bidirectional large-flow hydraulic control device - Google Patents
Differential pressure matching type bidirectional large-flow hydraulic control device Download PDFInfo
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- CN113323933B CN113323933B CN202110557111.2A CN202110557111A CN113323933B CN 113323933 B CN113323933 B CN 113323933B CN 202110557111 A CN202110557111 A CN 202110557111A CN 113323933 B CN113323933 B CN 113323933B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/021—Valves for interconnecting the fluid chambers of an actuator
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/22—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/027—Check valves
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
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- Analytical Chemistry (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The invention discloses a differential pressure matching type bidirectional high-flow hydraulic control device. The device mainly comprises a servo motor, a miniature bidirectional gear pump, a controller, a two-position two-way electromagnetic valve and a differential pressure matching type bidirectional flow control valve; the oil inlet and outlet of the miniature bidirectional gear pump are connected with different oil cavities of the control unit, and the two-position two-way electromagnetic valve controls the oil inlet and outlet of the miniature gear pump, and the bidirectional gear pump generates controllable micro flow to flow through the throttling channel to generate controllable pressure difference. The invention can also ensure low cost, reliability, convenient and stable control, environmental protection, insensitivity to oil temperature and cleanliness and effective guarantee of high-flow position and speed requirements when being used for high-flow accurate control.
Description
Technical Field
The invention belongs to the technical field of hydraulic control, and particularly relates to a bidirectional large-flow control system based on a differential pressure matching type flow control valve.
Background
Hydraulic transmission systems are widely used in various electromechanical devices, and hydraulic valves are core elements in hydraulic systems for controlling the pressure, flow and direction of a fluid, which have important effects on the performance, reliability and economy of the hydraulic system. The flow valve adjusts the passing flow by changing the opening of the throttle valve port, thereby controlling the movement speed of the load equipment, and is one of three types of hydraulic valves. In the control of many high power systems, the flow control valve is required to be able to control large flows accurately and quickly. The traditional large-flow control valve is generally designed into a multi-stage valve mode, namely, a pilot valve is used for controlling the pressure difference at two ends of a main valve, and the movement of a main valve core is controlled, so that the control of large flow is realized through the main valve core. Therefore, between the multi-stage control valves, displacement control of the pilot spool to the main spool must be realized in various inter-stage feedback modes, and then flow regulation is completed through the main valve port on the main spool, so as to realize a larger flow control level. The problem brought by the control mode is that the overall manufacturing precision of the valve is high, the control mode is complex, and the cleanliness of the valve for the system oil is also high, so that the overall cost of the valve is high, and the use occasion of the valve is limited.
Along with the increasing demands of the flow valve in the aspects of reliability, leakage, opening and closing dynamic characteristics, load adaptability and the like, the advantages of various existing large-flow control valves and feedback modes thereof are integrated under the condition of large flow, the problems that the existing large-flow proportional valve and servo valve are high in cost and difficult to control and the limitations in the aspects of reliability, valve core displacement control precision or response speed and the like are overcome, and a novel large-flow control valve or a novel large-flow control device is explored and developed based on an innovative flow control mode and is imperative for a large-flow hydraulic control system are overcome.
Disclosure of Invention
In order to solve the problems in the background art, the invention provides a bidirectional high-flow hydraulic control device based on pressure difference matching, which can ensure low cost, reliability, convenience and stability in control, is environment-friendly, is insensitive to oil temperature and cleanliness and can effectively ensure the position and speed requirements of high flow when being used for high-flow accurate control.
The invention creatively realizes bidirectional large-flow control by using a small-flow device by utilizing the pressure difference matching relation between different chokes on the same valve core. The device integrates the function of a hydraulic lock, and the miniature servo motor is used for driving the miniature gear pump to digitally control part of oil ways of the large-flow control device, so that the hydraulic oil flow passing through a given throttling channel is accurately controlled, a controllable pressure difference is generated, and the flow in a main oil way is accurately controlled in a pressure matching mode. Therefore, accurate control of bidirectional large flow is realized by small input power.
The technical scheme adopted by the invention is as follows:
1. differential pressure matching type bidirectional large-flow hydraulic control unit
The device mainly comprises a servo motor, a miniature bidirectional gear pump, a controller, a two-position two-way electromagnetic valve and a differential pressure matching type bidirectional flow control valve;
the differential pressure matching type bidirectional flow control valve comprises a valve body, an upper cavity and a lower cavity, wherein the upper cavity and the lower cavity are respectively arranged at the upper part and the lower part inside the valve body, the upper cavity and the lower cavity are directly and coaxially communicated, and the inner diameter of the upper cavity is larger than that of the lower cavity, so that a step is formed between the upper cavity and the lower cavity; the top of the valve body at the top of the upper cavity is provided with a top oil port, the bottom of the valve body at the bottom of the lower cavity is provided with a bottom oil port, and the side wall of the valve body between the upper cavity and the lower cavity is provided with a middle oil port and a hydraulic oil port;
the control shaft of the miniature bidirectional gear pump is connected with a servo motor, the servo motor is electrically connected with a controller, one oil port of the miniature bidirectional gear pump is connected with the top oil port of the differential pressure matching type bidirectional flow control valve, and the other oil port of the miniature bidirectional gear pump is connected with the middle oil port of the differential pressure matching type bidirectional flow control valve through a two-position two-way electromagnetic valve;
an upper piston is arranged in an upper cavity of the bidirectional flow control valve, the upper piston divides the upper cavity into an upper oil cavity positioned above and an upper lower oil cavity positioned below, an annular groove is formed in the inner wall of the middle of the upper cavity and is used as an upper sinking cutting groove, the upper oil cavity and the upper sinking cutting groove are communicated through an upper valve body inner oil duct arranged in the valve body, and an upper spring is connected between the upper piston and the inner top surface of the upper cavity; a lower piston is arranged in a lower cavity of the bidirectional flow control valve, the lower piston divides the lower cavity into a lower upper oil cavity positioned above and a lower oil cavity positioned below, an annular groove is formed in the inner wall of the middle of the lower cavity and is used as a sinking cutting groove, the lower upper oil cavity and the sinking cutting groove are communicated through a lower valve body inner oil duct arranged in the valve body, and a lower spring is connected between the lower piston and the inner bottom surface of the lower cavity; the elastic force of the upper spring is larger than that of the lower spring; an intermediate cone valve is fixedly connected between the upper piston and the lower piston, and the conical surface of the intermediate cone valve is used for being matched and connected with the step surface between the upper cavity and the lower cavity in the valve body.
The outer edges of the bottom surfaces of the upper piston and the lower piston are respectively provided with a notch groove serving as a throttling groove; the throttling groove of the upper piston is always communicated with the sinking cutting groove, and the throttling groove of the upper piston is always communicated with the sinking cutting groove.
The axial groove width of the upper sinking cutting groove is smaller than the thickness of the upper piston and the upper cavity inner wall in actual contact, and the axial groove width of the sinking cutting groove is smaller than the thickness of the lower piston and the lower cavity inner wall in actual contact.
The top oil port and the middle oil port are used as internal flow ports of the hydraulic large-flow control unit, the hydraulic oil port and the bottom oil port are used as external flow ports of the hydraulic large-flow control unit, the hydraulic oil port is connected with a hydraulic load, and the bottom oil port is connected with an oil tank; the flow between the tank and the hydraulic load is greater than the operating flow of the bi-directional gear pump.
An upper throttling channel is formed between the throttling groove on the bottom surface of the upper piston and the lower edge of the upper sinking cutting groove, and a lower throttling channel is formed between the throttling groove on the bottom surface of the lower piston and the lower edge of the sinking cutting groove; the upper piston, the lower piston and the middle cone valve are coaxially connected to form a valve core, the valve core moves up and down along the axial direction in the upper cavity and the lower cavity to drive the upper throttling channel and the lower throttling channel to increase and decrease, and the flow regulation control is realized.
When the step surfaces between the middle cone valve and the upper cavity and the lower cavity are matched, contacted and sealed, the upper throttling channel and the lower throttling channel keep flowing, and the minimum throttling area is provided; as the middle cone valve rises, the upper and lower throttle passages are continuously increased.
2. A differential pressure matching type bidirectional large-flow hydraulic control method comprises the following steps:
a) When the bottom oil port is filled with high-pressure oil, the hydraulic oil port is connected with a low-pressure oil way, the high-pressure oil enters a lower oil cavity at the lower part to push the valve core to move upwards, the middle cone valve is opened, and the upper oil cavity at the upper part is communicated with the upper oil cavity at the lower part; meanwhile, the controller opens the two-position two-way electromagnetic valve, controls the two-way gear pump to pump hydraulic oil into the upper oil cavity from the lower oil cavity at a lower flow rate, increases the oil pressure in the upper oil cavity, increases the downward pressure difference suffered by the upper piston, and further, because the area of the upper piston is larger than that of the lower piston, the pressure difference force of the upper piston changes more rapidly, so that the valve core is simultaneously subjected to the thrust of the upward high-pressure oil and the downward pressure caused by the suction of the two-way gear pump 17; the rotating speed, namely the flow rate, of the bidirectional gear pump is regulated, so that the upward differential pressure force born by the lower piston and the downward differential pressure force born by the upper piston are balanced, namely the valve core reaches an equilibrium position, and the equilibrium position is determined by the flow rate required by a system;
At the moment, the flow from the bottom oil port to the hydraulic oil port is positively controlled by the miniature bidirectional gear pump, namely, the flow discharged by the bidirectional gear pump is increased, the downward differential pressure force applied to the upper piston is increased, the upward differential pressure force applied to the lower piston is unchanged, the valve core can be lowered and reaches the position of differential pressure force balance again, the throttling area of the upper throttling channel is reduced, and the throttling area of the lower throttling channel is synchronously reduced, so that the flow of the system overcurrent is also reduced;
or reverse control is realized according to the reverse direction of the forward control;
b) When the hydraulic oil port is filled with high-pressure oil, the bottom oil port is connected with a low-pressure oil path; when the controller opens the two-position two-way electromagnetic valve and controls the two-way gear pump to pump hydraulic oil into the upper lower oil cavity from the upper oil cavity with smaller flow; in the process, the oil pressure in the upper oil cavity of the upper part is reduced by the suction of the bidirectional gear pump, the pressure in the lower oil cavity of the upper part is unchanged, so that the upper piston receives upward pressure difference force, and the upward pressure difference force received by the upper piston is increased faster because the area of the upper piston is larger than that of the lower piston;
When the rotating speed of the bidirectional gear pump reaches high enough speed and the flow rate reaches high enough speed, the pressure difference force born by the upper piston is larger than the pressure difference force born by the middle cone valve, the valve core is pushed to move upwards, the middle cone valve is opened, and the communication between the upper lower oil cavity and the lower upper oil cavity is opened; the rotating speed, namely the flow, of the bidirectional gear pump is regulated, so that the differential pressure forces borne by the upper piston and the lower piston of the valve core are balanced, and finally the valve core reaches the balance position; at the moment, oil flows from the hydraulic oil port through the lower upper oil cavity, the oil duct and the undercut groove, and then flows into the bottom oil port through the lower throttling channel and the lower oil cavity;
at this time, the flow from the hydraulic oil port to the bottom oil port is positively controlled by the miniature bidirectional gear pump: the flow discharged by the bidirectional gear pump is increased, the upward pressure difference force borne by the upper piston is increased, the valve core is lifted, the throttling area of the upper throttling channel is increased, and the throttling area of the lower throttling channel is synchronously increased, so that the flow of the system overcurrent is also increased;
or reverse control is performed in accordance with the reverse of the above-described forward control.
Said B) is replaced by the following C):
c) A second two-position two-way electromagnetic valve is added in the system oil way, one oil port of the second two-position two-way electromagnetic valve is connected between the oil ways of the two-way gear pump and the two-position two-way electromagnetic valve, and the other oil port is connected with the bottom oil port of the two-way flow control valve;
When the hydraulic oil port is filled with high-pressure oil, the bottom oil port is connected with a low-pressure oil way, and at the beginning, the upper throttling channel on the upper piston is communicated with the oil way in the upper valve body, so that the upper pressure and the lower pressure borne by the upper piston are equal, the middle cone valve is pressed on a step of the valve body by the high-pressure oil pressure at the hydraulic oil port, at the moment, the controller closes the two-position two-way electromagnetic valve, opens the second two-position two-way electromagnetic valve, and simultaneously controls the two-way gear pump to pump hydraulic oil from an upper oil cavity at a lower oil cavity with a smaller flow rate; in the process, the oil pressure in the upper oil cavity of the upper part is reduced by the suction of the bidirectional gear pump, the pressure in the lower oil cavity of the upper part is unchanged, so that the upward pressure difference force born by the upper piston is increased faster because the area of the upper piston is larger than that of the lower piston;
when the rotating speed of the bidirectional gear pump reaches high enough speed and the flow rate reaches high enough speed, the pressure difference force born by the upper piston is larger than the pressure difference force born by the middle cone valve, the valve core is pushed to move upwards, the middle cone valve is opened, and the communication between the upper lower oil cavity and the lower upper oil cavity is opened; the rotating speed, namely the flow, of the bidirectional gear pump is regulated, and finally, the differential pressure forces borne by the upper piston and the lower piston of the valve core are balanced, so that the valve core reaches the balance position; the oil flows from the hydraulic oil port through the lower upper oil cavity, the oil duct and the undercut groove, and then flows into the bottom oil port through the lower throttling channel and the lower oil cavity.
At this time, the flow from the hydraulic oil port to the bottom oil port is positively controlled by the miniature bidirectional gear pump: the flow discharged by the bidirectional gear pump is increased, the upward pressure difference force borne by the upper piston is increased, the valve core is lifted, the throttling area of the upper throttling channel is increased, and the throttling area of the lower throttling channel is synchronously increased, so that the flow of the system from the oil port to the overflow of the oil port is also increased;
or reverse control is performed in accordance with the reverse of the above-described forward control.
Therefore, the purpose of accurately controlling the large flow from the hydraulic oil port to the bottom oil port by accurately controlling the tiny flow discharged by the miniature gear pump is achieved.
The oil inlet and outlet ports of the bidirectional miniature gear pump are respectively connected with different oil cavities of the control unit, and the two-position two-way electromagnetic valve is used for controlling the oil inlet and outlet ports of the miniature gear pump, and controllable micro flow generated by the bidirectional gear pump flows through the throttling channel and generates controllable pressure difference at two ends of the throttling channel; and the miniature servo motor is connected with the bidirectional gear pump.
When no control signal is input, the flow control device is equivalent to a simple hydraulic one-way valve and is used for stopping hydraulic oil from flowing from the middle oil port to the bottom oil port. But when being used for precisely controlling large flow, the device can completely replace the traditional proportional control valve to realize the precise control of the flow, thereby precisely controlling the movement speed of the controlled oil cylinder.
The control device is only started when the pressure oil is required to be supplied, so that the control device has high energy utilization efficiency. Meanwhile, the control mode is digital control, the flow of the miniature quantitative pump is controlled through the miniature servo motor, and the flow of the main oil way is controlled through a large amplification factor, so that the control is convenient and reliable.
The differential pressure matching type bidirectional flow control valve is characterized in that: the opening degree of a throttling channel on a piston in the valve core is always synchronous through the size of machining, and the throttling area is in a certain proportion, so that the flow of hydraulic oil entering and exiting the oil cylinder and the flow discharged by the miniature gear pump are in a fixed proportion relation, and the valve is completely controllable. Namely, the method comprises the following steps: the hydraulic oil flow in and out of the whole flow control device is controlled by controlling the hydraulic oil flow in different oil cavities in the miniature bidirectional gear pump sucking or pumping differential pressure matching type bidirectional flow control valve, and the flow control device is hardly influenced by the outside.
Therefore, compared with the prior art, the invention has the following beneficial effects:
1. the flow control system based on the pressure difference matching type bidirectional flow control valve is low in cost, stable and reliable, and the original servo or proportional valve for controlling the flow can be abandoned, so that the cost of the hydraulic control system is greatly reduced;
2. The flow control system based on the differential pressure matching type bidirectional flow control valve reduces the processing difficulty and reduces the influence on the cleanliness requirement and the oil temperature of the hydraulic oil due to the reduction of the requirement of a flow feedback link;
3. compared with the traditional hydraulic servo system based on the proportional valve or the servo valve, the flow control system of the differential pressure matching type bidirectional flow control valve provided by the invention can effectively control the flow in the hydraulic system, and the control method is greatly simplified, and the flow of hydraulic oil entering and exiting the oil cylinder can be accurately controlled only by controlling the rotating speed of the servo motor in the system.
4. The flow control system based on the pressure difference matching type bidirectional flow control valve belongs to a positive displacement control system (pump control system), and compared with a proportional valve or a servo valve, the energy efficiency of the hydraulic control system can be effectively improved, and the heating value of the system is reduced.
In summary, the digital control type hydraulic flow control unit provided by the invention has the advantages that the cost is low even when the digital control type hydraulic flow control unit is used for precisely controlling large flow, the digital control type hydraulic flow control unit is reliable, convenient and stable to control, environment-friendly in use and insensitive to oil temperature and cleanliness, and the running position and speed requirements of an execution unit in a large-flow hydraulic system can be effectively ensured.
Drawings
FIG. 1 is a schematic diagram of a differential pressure matching type bidirectional flow control device in a first working state;
FIG. 2 is a schematic diagram of a differential pressure matching type bidirectional flow control device in a second working state;
FIG. 3 is a schematic diagram of a differential pressure matching type bidirectional flow control device in a third working state;
FIG. 4 is a schematic diagram of a differential pressure matching type bidirectional flow control device in a fourth working state;
fig. 5 is a schematic structural diagram of the differential pressure matching type bidirectional flow control device in the working state five.
In the figure: the hydraulic oil pump comprises an upper spring 1, an upper oil cavity 2, an upper undercut groove 3, an upper piston 4, an upper throttle channel 5, a hydraulic oil port 6, an upper lower oil cavity 7, a middle cone valve 8, a lower upper oil cavity 9, a undercut groove 10, a lower piston 11, a lower throttle channel 12, a bottom oil port 13, a lower spring 14, a two-position two-way electromagnetic valve 16, a miniature two-way gear pump 17, a servo motor 18, a controller 19, a pressure difference matching type two-way flow control valve 20, a top oil port 21, a middle oil port 22, an upper valve body inner oil duct 23, a lower valve body inner oil duct 24, a lower oil cavity 25 and a second two-position two-way electromagnetic valve 15.
Detailed Description
The foregoing and other features and advantages of the invention will be apparent from the following, more particular, description of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts, rather than to the same parts.
As shown in fig. 1, a schematic diagram of a differential pressure-based two-way flow control valve and a flow control device according to an embodiment of the present invention mainly comprises a digitally controlled servo motor 18, a miniature two-way gear pump 17, a controller 19, a two-position two-way electromagnetic valve 16, and a differential pressure-based two-way flow control valve 20;
the differential pressure matching type bidirectional flow control valve 20 comprises a valve body, an upper cavity and a lower cavity which are respectively arranged in the valve body, wherein the valve body is hollow, the upper cavity and the lower cavity are directly and coaxially communicated, and the inner diameter of the upper cavity is larger than that of the lower upper cavity, so that a step is formed between the upper cavity and the lower cavity; the top oil port 21 is formed in the top of the valve body at the top of the upper cavity, the bottom oil port 13 is formed in the bottom end of the valve body at the bottom of the lower cavity, the middle oil port 22 and the hydraulic oil port 6 are formed in the side wall of the valve body between the upper cavity and the lower cavity, and the middle oil port 22 and the hydraulic oil port 6 can be symmetrically arranged on two sides;
the control shaft of the bidirectional gear pump 17 is connected with a servo motor 18, the servo motor 18 is electrically connected with a controller 19, the servo motor 18 is a low-power motor, the miniature bidirectional gear pump 17 is connected, and the controller 19 sends out a command to control the rotating speed of the servo motor 18, so that the flow of the miniature bidirectional gear pump 17 is controlled. One oil port of the bidirectional gear pump 17 is connected with a top oil port 21 of the differential pressure matching type bidirectional flow control valve 20, and the other oil port of the bidirectional gear pump 17 is connected with a middle oil port 22 through a two-position two-way electromagnetic valve 16;
The miniature bidirectional gear pump is driven by a digital control type servo motor or a direct current speed regulating motor; the two-position two-way electromagnetic valve is used for connecting and controlling an oil port of the miniature gear pump to different oil cavities of the differential pressure matching type two-way flow control valve; the servo motor is connected with a bidirectional gear pump.
An upper piston 4 is arranged in an upper cavity of the bidirectional flow control valve 20, the upper piston 4 divides the upper cavity into an upper oil cavity 2 positioned above the upper piston 4 and an upper lower oil cavity 7 positioned below the upper piston 4, an annular groove is formed in the inner wall of the middle of the upper cavity and is used as an upper undercut groove 3, the upper oil cavity 2 and the upper undercut groove 3 are always communicated through an upper valve body inner oil duct 23 arranged in the valve body, an upper spring 1 is connected between the upper piston 4 and the inner top surface of the upper cavity, and the inner top surface of the upper cavity is the inner top surface of the upper oil cavity 2; the lower cavity of the two-way flow control valve 20 is internally provided with a lower piston 11, the lower piston 11 divides the lower cavity into a lower upper oil cavity 9 positioned above the lower piston 11 and a lower oil cavity 25 positioned below the lower piston 11, the inner wall of the middle part of the lower cavity is provided with an annular groove serving as a sinking cutting groove 10, the lower upper oil cavity 9 and the sinking cutting groove 10 are always communicated through a lower valve body inner oil duct 24 arranged in the valve body, a lower spring 14 is connected between the lower piston 11 and the inner bottom surface of the lower cavity, and the inner top surface of the lower cavity is the inner top surface of the lower oil cavity 25; the middle cone valve 8 is fixedly connected between the upper piston 4 and the lower piston 11, the upper piston 4, the lower piston 11 and the middle cone valve 8 are coaxially and fixedly connected, and the bottom surface of the periphery of the middle cone valve 8 is used for being matched and connected with the step surface between the upper cavity and the lower cavity to form a seal; the upper piston 4, the lower piston 11 and the middle cone valve 8 are coaxially connected to form a valve core of the oil cavity.
The outer edges of the bottom surfaces of the upper piston 4 and the lower piston 11 are provided with notch grooves as throttling grooves, and the size is ensured by machining, so that the upper throttling groove and the lower throttling groove are always synchronously opened and used as variable throttling channels, and the throttling area is ensured to always keep the same proportion in the moving process of the valve core; the throttling groove of the upper piston 4 is always communicated with the upper sinking cutting groove 3, and the throttling groove of the lower piston 11 is always communicated with the sinking cutting groove 10.
The axial groove width of the upper undercut groove 3 is smaller than the thickness of the upper piston 4 actually contacting the inner wall of the upper cavity, and the axial groove width of the lower undercut groove 10 is smaller than the thickness of the lower piston 11 actually contacting the inner wall of the lower cavity.
The top oil port 21 and the middle oil port 22 are used as internal flow ports of the hydraulic large-flow control unit, the hydraulic oil port 6 and the bottom oil port 13 are used as external flow ports of the hydraulic large-flow control unit, the hydraulic oil port 6 is connected with a hydraulic load, the hydraulic load is usually one cavity of a hydraulic cylinder, and the bottom oil port 13 is connected with an oil tank; the flow between the tank and the hydraulic load is much greater than the operating flow of the bi-directional gear pump 17.
The hydraulic oil port 6 of the differential pressure matching type bidirectional flow control valve is an oil outlet and is connected with a controlled hydraulic cylinder or other oil ways; the bottom oil port 13 of the bidirectional flow control valve 20 is an oil inlet and is connected with an oil supply way or an oil tank; but can also be exchanged, the hydraulic oil port 6 is an oil inlet, and the bottom oil port 13 is an oil outlet.
The middle oil port and the bottom oil port of the differential pressure matching type flow control valve can be used as an oil inlet or an oil outlet of the flow control valve, so that bidirectional flow control is realized.
An upper throttling channel 5 is formed between the throttling groove on the bottom surface of the upper piston 4 and the lower edge of the upper undercut groove 3, and a lower throttling channel 12 is formed between the throttling groove on the bottom surface of the lower piston 11 and the lower edge of the undercut groove 10; the upper piston 4, the lower piston 11 and the middle cone valve 8 are coaxially connected to form a valve core, and the valve core moves up and down along the axial direction in the upper cavity and the lower cavity to drive the upper throttling channel 5 and the lower throttling channel 12 to increase and decrease, so that the flow regulation and control are realized. The upper throttle passage 5 and the lower throttle passage 12 change in the same direction, i.e. the upper throttle passage 5 increases, so does the lower throttle passage 12, and vice versa. This ensures that the throttle is synchronously opened, the throttle area is synchronously changed with the displacement of the valve core, but the ratio of the throttle areas on the upper piston and the lower piston remains unchanged.
In specific implementation, the two-position two-way electromagnetic valve 16 is electrically connected to the controller 19, and the controller 19 drives the two-position two-way electromagnetic valve 16 to work on and off.
The oil inlet and outlet of the two-way miniature gear pump are respectively connected with different oil cavities of the flow control unit, the on-off of the oil inlet and outlet of the miniature gear pump is controlled by a two-position two-way electromagnetic valve, and controllable micro flow generated by the two-way gear pump flows through a V-shaped throttling channel on a valve core piston and generates controllable pressure difference at two ends of the V-shaped throttling channel.
The positions of the V-shaped groove on the piston, the undercut groove on the valve body and the step are required to be strictly matched, so that a throttling passage on the piston only has a tiny throttling area for conducting hydraulic oil pressure before the cone valve core is lifted. Specifically, when the middle cone valve 8 and the step surfaces between the upper cavity and the lower cavity are in matched contact sealing, the upper throttling channel 5 and the lower throttling channel 12 keep to circulate, and have the smallest throttling area; as the intermediate cone valve 8 rises, the upper throttle passage 5 and the lower throttle passage 12 are increased.
The specific throttling groove is arranged as a V-shaped throttling groove or can be arranged in other shapes such as a semicircular arc shape or a diamond shape.
The flow rate flowing through the flow control unit is determined by the pressure difference of the V-shaped throttling channel on the lower piston in the valve core in the flow control valve and the opening of the V-shaped throttling channel. The throttle pressure difference and the position opening degree on the lower piston of the valve core of the pressure difference matching type flow control valve are determined by digital signals for controlling the rotating speed and the rotating direction of the servo motor and the flow of the miniature bidirectional gear pump.
The miniature bidirectional gear pump can also be arranged as a unidirectional gear pump combined electromagnetic directional valve to realize bidirectional flow output.
The bi-directional gear pump 17 is a miniature small flow fixed displacement pump for providing precisely controllable control flow.
The servo motor 18 is a low-power motor, the low-power motor is used for pushing the valve core to move, the servo motor is connected with the bidirectional gear pump 17, and the controller 19 sends out a command to control the rotating speed.
The invention controls the structure of large flow through the structure of small flow, the small flow is used for controlling the movement and the position of the valve core, the large flow is used for controlling the whole flow flowing out of the flow control valve to be large, and the digital accurate control under the hydraulic large flow is realized.
The pressure difference of the piston is the pressure difference between the upper end face and the lower end face. The pressure difference force represents the difference between the thrust force and the pressure difference between the upper and lower pressure, i.e. the pressure difference is multiplied by the corresponding piston area
Referring to fig. 1, operating state one:
when the system is in a standby state, no control instruction is sent in the controller 19, the servo motor 18 and the bidirectional gear pump 17 are in a standby state, the two-position two-way electromagnetic valve 16 is not communicated, at the moment, the bottom oil port 13 of the bidirectional flow control valve 20 is not supplied with pressure oil, the pressure is zero, and the hydraulic oil port 6 of the bidirectional flow control valve 20 is connected with a load, and can be a certain cavity of an oil cylinder, so that the pressure generated by the load exists; in addition, in the initial state, the throttling channels on the upper piston 4 and the lower piston 11 of the valve core are communicated with each other by a small throttling area for conducting hydraulic oil pressure; the oil pressure of the upper oil chamber 2 above the upper piston 4 is thus equal to the oil pressure of the upper lower oil chamber 7 below the upper piston 4 and to the pressure generated by the load, the upper piston 4 being unstressed; meanwhile, the pressure of the lower upper oil cavity 9 above the lower piston 11 is equal to the pressure of the lower oil cavity 25 below the lower piston, and the pressure is zero; therefore, the middle cone valve 8 is acted by the pressure difference between the upper lower oil cavity 7 and the lower upper oil cavity 9 to form downward pressure, and is tightly pressed on the step surface in the valve body to form reliable seal, thereby stopping the flow of hydraulic oil from the hydraulic oil port 6 to the bottom oil port 13 and locking the hydraulic cylinder in one way.
Or when the bottom oil port 13 and the hydraulic oil port 6 are both supplied with pressure oil, the pressure is zero; at this time, since the spring force of the upper spring 1 is greater than the spring force of the lower spring 14, the middle cone valve 8 is also pressed against the stepped surface in the valve body by the spring force, so that a reliable seal is formed.
The operating condition of the two-way flow control valve 20 at this time resembles a hydraulic one-way valve.
Referring to fig. 2, operating state two:
when the bottom port 13 of the bidirectional flow control valve 20 has high pressure hydraulic oil and the hydraulic port 6 has low pressure hydraulic oil, but it is necessary to stop the flow of pressure oil from the bottom port 13 to the hydraulic port 6:
at this time, a control command is sent out from the controller 19, so that the two-position two-way electromagnetic valve 16 is communicated, the servo motor 18 drives the two-way gear pump 17 to pump the oil in the upper lower oil cavity 7 of the two-way flow control valve 20 into the upper oil cavity 2 according to a specified rotating speed, and then the oil returns to the upper lower oil cavity 7 sequentially through the upper valve body inner oil duct 23, the upper undercut groove 3 and the upper throttling channel 5 below the upper piston 4, in the process, the oil pressure in the upper oil cavity 2 is increased, the pressure of the upper lower oil cavity 7 is not equal to the pressure of the oil port 6, and the downward differential pressure force applied to the upper piston 4 is increased; because the throttling passage on the lower piston 11 is communicated with a small throttling area for conducting hydraulic oil pressure, the oil pressure in the lower upper oil cavity 9 is larger and equal to the pressure at the bottom oil port 13, the pressure difference between the upper and lower parts of the lower piston 11 is zero, and the upper piston 11 is not stressed; while the middle cone valve 8 is subjected to an upward pressure differential force; however, because the upper piston 4 has a larger area of action, the intermediate cone valve 8 has a smaller area of action, and the upper piston receives a greater downward pressure at the same pressure difference. At this time, hydraulic oil is continuously pumped into the upper oil chamber 2 by adjusting the rotation speed, i.e., the flow rate, of the bidirectional gear pump 17, and when the downward differential pressure force applied to the upper piston 4 is sufficiently large enough to exceed the upward differential pressure force applied to the middle cone valve 8, the differential pressure force applied to the valve core is comprehensively made downward, i.e., the middle cone valve 8 and the step surface are tightly pressed and sealed, so that the oil flow between the upper lower oil chamber 7 and the lower upper oil chamber 9 is blocked.
This causes the minute flow discharged from the two-way gear pump 17 to generate a pressure acting on the piston 4 after flowing through the throttle passage large enough to overcome the force of the pressure of the bottom port 13 of the two-way flow control valve 20 acting on the intermediate cone valve 8, the cone valve portion in the middle of the spool of the flow control valve 20 will always remain closed, i.e., the state of fig. 2, thereby shutting off the flow of hydraulic oil from the port 13 to the port 6.
Referring to fig. 3, operating state three:
when the bottom oil port 13 of the bidirectional flow control valve 20 has high pressure oil, the hydraulic oil port 6 is connected with a low pressure oil path, and the flow from the bottom oil port 13 to the hydraulic oil port 6 needs to be accurately controlled;
initially, the throttle channels on the upper piston 4 and the lower piston 11 of the valve core are communicated with each other by a small throttle area for conducting hydraulic oil pressure, and the oil pressure in the upper oil cavity 2 of the upper piston 4 is equal to the oil pressure in the upper lower oil cavity 7 and is equal to the low-pressure oil circuit oil pressure; the oil pressure in the lower upper oil chamber 9 of the lower piston 11 is equal to the oil pressure in the lower oil chamber 25 and is equal to the high-pressure oil line pressure; therefore, the pressure difference is formed on the upper surface and the lower surface of the middle cone valve 8, and the pressure difference force is upward, so that the valve core is driven to move upward, and the middle cone valve 8 and the step surface are separated; the upper lower oil cavity 7 is communicated with the lower upper oil cavity 9;
Meanwhile, the controller 19 controls the two-position two-way electromagnetic valve 16 to be communicated, and adopts closed-loop control to control the rotating speed of the two-way gear pump 17, and simultaneously collects flow information required by the oil outlet 6 or operation speed information of a corresponding oil cylinder; pumping the oil in the upper lower oil cavity 7 into the upper oil cavity 2 through the bidirectional gear pump 17, and returning the oil to the upper lower oil cavity 7 through the upper valve body inner oil duct 23, the upper undercut groove 3 and the upper throttling channel 5 below the upper piston 4 in sequence; by controlling the rotation speed of the bidirectional gear pump 17, the oil pressure in the upper oil cavity 2 is continuously pumped in, and the pressure difference of the depression applied to the upper piston 4 is increased because the lower oil cavity 7 is communicated with the hydraulic oil port 6 and the pressure is unchanged; since the area of the upper piston 4 is larger than that of the lower piston 11, the same pressure difference is changed, and the pressure difference force change amount of the upper piston is larger; therefore, the flow discharged by the bidirectional gear pump 17 is controlled so that the pressure difference force acted on the upper piston 4 after flowing through the throttling channel can just balance the upward pressure difference force acted on the lower piston 11, namely the pressure on the upper piston and the lower piston are just balanced, the middle cone valve 8 is separated from the step surface, the upper lower oil cavity 7 is communicated with the lower upper oil cavity 9, and the balance position is kept, and is determined by the flow required by the system, namely the operation speed required by the oil cylinder; the bottom port 13 to the hydraulic port 6 to the flow will also reach equilibrium.
At this time, the flow rate from the bottom port 13 to the hydraulic port 6 is controlled by the micro bi-directional gear pump 17: namely, the flow discharged by the bidirectional gear pump 17 is increased, the downward pressure difference force borne by the upper piston 4 is increased, and the upward pressure difference force borne by the lower piston 11 is unchanged, so that the valve core is lowered, the throttling area of the upper throttling channel 5 is reduced, the throttling area of the lower throttling channel 12 is synchronously reduced, and the flow of the overflow of the whole system device is also reduced; and vice versa.
Because the throttling areas of the two throttling channels can have a larger proportion relation, the large flow from the oil port 13 to the oil port 6 can be accurately controlled by controlling the discharge flow of the miniature gear pump; namely, the micro bi-directional gear pump 17 is used for controlling the pressure difference at two ends of the upper piston 4 to accurately control the position of the valve core, and the opening degree of the throttle channel of the valve core is controlled, so that the large flow passing through the whole system is controlled.
Referring to fig. 4, operating state four: based on the same pressure difference matching pattern.
When the pressure of the hydraulic oil port 6 of the bidirectional flow control valve 20 is greater than the pressure of the bottom oil port 13, and the flow rate from the hydraulic oil port 6 to the bottom oil port 13 needs to be accurately controlled;
at the beginning, the small throttling areas of the throttling channels on the upper piston 4 and the lower piston 11 of the valve core are communicated with each other for conducting hydraulic oil pressure, and the oil pressure in the upper oil cavity 2 of the upper part of the upper piston 4 is equal to the oil pressure in the lower oil cavity 7 of the upper part and is equal to the oil pressure of a high-pressure oil way; the oil pressure in the lower upper oil chamber 9 of the lower piston 11 is equal to the oil pressure in the lower oil chamber 25 and is equal to the low-pressure oil line pressure; therefore, the pressure difference is formed on the upper surface and the lower surface of the middle cone valve 8, and the pressure difference force is downward, so that the middle cone valve 8 compresses the step surface of the valve body;
Meanwhile, the controller 19 still adopts a closed-loop control mode to control and open the two-position two-way electromagnetic valve 16 to communicate, and simultaneously collects flow information required by the oil port 6 or operation speed information of a corresponding oil cylinder; controlling the flow discharged by the micro gear pump 17 through the servo motor 18, and sucking and pumping the oil in the upper oil cavity 2 into the upper lower oil cavity 7; during this process, the oil pressure in the upper oil chamber 2 decreases; because the oil port 6 is loaded with high pressure and high oil pressure, that is, the pressure of the upper lower oil chamber 7 is high and unchanged, the upper piston 4 is subjected to an upward pressure difference in the process of reducing the oil pressure of the upper oil chamber 2, and when the pressure difference is high enough, the valve core is pushed to move upwards, the middle cone valve 8 is separated from the step surface, and the communication between the upper lower oil chamber 7 and the lower upper oil chamber 9 is opened.
After the middle cone valve 8 and the step surface are separated, oil in the upper lower oil cavity 7 enters the lower upper oil cavity 9, so that the oil pressure in the lower upper oil cavity 9 is larger than the oil pressure in the lower oil cavity 25, and the lower piston 11 receives a downward pressure difference force; the upper piston 4 is always subjected to an upward pressure differential force, due to the pumping action of the gear pump 17 on the upper chamber 2, and the oil pressure in the upper lower chamber 7 is relatively high. Finally, by controlling the flow discharged by the micro gear pump 17, the downward differential pressure force applied to the lower piston 11 and the upward differential pressure force applied to the upper piston 4 are balanced, and according to the running speed required by the system oil cylinder, the valve core can finally stay at a certain balance position, and the flow from the hydraulic oil port 6 to the bottom oil port 13 can be balanced.
At this time, the flow rate from the hydraulic port 6 to the bottom port 13 is controlled by the micro bi-directional gear pump 17: that is, the flow rate discharged by the bidirectional gear pump 17 is increased, the upward pressure difference borne by the upper piston 4 is increased, the downward pressure difference borne by the lower piston 11 is unchanged, the valve core is pushed to rise, the throttling area of the upper throttling channel 5 is increased, the throttling area of the lower throttling channel 12 is also increased synchronously, and the flow rate of the overflow of the whole system device is also increased; and vice versa.
Therefore, by accurately controlling the minute flow rate discharged from the micro gear pump 17, the large flow rate from the hydraulic oil port 6 to the bottom oil port 13 can be accurately controlled.
Referring to fig. 5, operating state five: compared with the state of the working state 4, a two-position two-way electromagnetic valve is added
In the system oil way, a second two-position two-way electromagnetic valve (15) is added, one oil port of the second two-position two-way electromagnetic valve (15) is connected between the oil way of the two-way gear pump (17) and the two-position two-way electromagnetic valve (16), and the other oil port is connected with the bottom oil port (13) of the two-way flow control valve (20);
when the pressure of the hydraulic oil port 6 of the bidirectional flow control valve 20 is greater than the pressure of the bottom oil port 13, and the flow rate from the hydraulic oil port 6 to the bottom oil port 13 needs to be accurately controlled;
At the beginning, the small throttling areas of the throttling channels on the upper piston 4 and the lower piston 11 of the valve core are communicated with each other for conducting hydraulic oil pressure, and the oil pressure in the upper oil cavity 2 of the upper part of the upper piston 4 is equal to the oil pressure in the lower oil cavity 7 of the upper part and is equal to the oil pressure of a high-pressure oil way; the oil pressure in the lower upper oil chamber 9 of the lower piston 11 is equal to the oil pressure in the lower oil chamber 25 and is equal to the low-pressure oil line pressure; therefore, the pressure difference is formed on the upper surface and the lower surface of the middle cone valve 8, and the pressure difference force is downward, so that the middle cone valve 8 compresses the step surface of the valve body;
meanwhile, the controller 19 still adopts a closed-loop control mode to control the two-position two-way electromagnetic valve 16 to be closed, and opens the second two-position two-way electromagnetic valve 15 to be communicated, and simultaneously collects flow information required by the oil port 6 or operation speed information of a corresponding oil cylinder; controlling the flow discharged by the micro gear pump 17 through the servo motor 18, and sucking and pumping the oil in the upper oil cavity 2 into the lower oil cavity 25; during this process, the oil pressure in the upper oil chamber 2 decreases; because the oil port 6 is loaded with high pressure and high oil pressure, that is, the pressure of the upper lower oil chamber 7 is high and unchanged, the upper piston 4 is subjected to an upward pressure difference in the process of reducing the oil pressure of the upper oil chamber 2, and when the pressure difference is high enough, the valve core is pushed to move upwards, the middle cone valve 8 is separated from the step surface, and the communication between the upper lower oil chamber 7 and the lower upper oil chamber 9 is opened.
After the middle cone valve 8 and the step surface are separated, oil in the upper lower oil cavity 7 enters the lower upper oil cavity 9, so that the oil pressure in the lower upper oil cavity 9 is larger than the oil pressure in the lower oil cavity 25, and the lower piston 11 receives a downward pressure difference force; the upper piston 4 is always subjected to an upward pressure differential force, due to the pumping action of the gear pump 17 on the upper chamber 2, and the oil pressure in the upper lower chamber 7 is relatively high. Finally, by controlling the flow discharged by the micro gear pump 17, the downward differential pressure force applied to the lower piston 11 and the upward differential pressure force applied to the upper piston 4 are balanced, and according to the running speed required by the system oil cylinder, the valve core can finally stay at a certain balance position, and the flow from the hydraulic oil port 6 to the bottom oil port 13 can be balanced.
At this time, the flow rate from the hydraulic port 6 to the bottom port 13 is controlled by the micro bi-directional gear pump 17: that is, the flow rate discharged by the bidirectional gear pump 17 is increased, the upward pressure difference borne by the upper piston 4 is increased, the downward pressure difference borne by the lower piston 11 is unchanged, the valve core is pushed to rise, the throttling area of the upper throttling channel 5 is increased, the throttling area of the lower throttling channel 12 is also increased synchronously, and the flow rate of the overflow of the whole system device is also increased; and vice versa.
Therefore, by accurately controlling the minute flow rate discharged from the micro gear pump 17, the large flow rate from the hydraulic oil port 6 to the bottom oil port 13 can be accurately controlled.
The foregoing embodiments have been provided for the purpose of illustrating the general principles of the present invention, and are not to be construed as limiting the scope of the invention. It should be noted that any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art without departing from the spirit and principles of the present invention are intended to be included in the scope of the present invention.
Claims (7)
1. A differential pressure matching type bidirectional large-flow hydraulic control unit is characterized in that,
the device mainly comprises a servo motor (18), a miniature bidirectional gear pump (17), a controller (19), a two-position two-way electromagnetic valve (16) and a differential pressure matching type bidirectional flow control valve (20); the differential pressure matching type bidirectional flow control valve (20) comprises a valve body, an upper cavity and a lower cavity, wherein the upper cavity and the lower cavity are respectively arranged at the upper part and the lower part inside the valve body, the upper cavity and the lower cavity are directly and coaxially communicated, and the inner diameter of the upper cavity of the upper part is larger than that of the lower cavity of the lower part, so that a step is formed between the upper cavity and the lower cavity; the top of the valve body at the top of the upper cavity is provided with a top oil port (21), the bottom of the valve body at the bottom of the lower cavity is provided with a bottom oil port (13), and the side wall of the valve body between the upper cavity and the lower cavity is provided with a middle oil port (22) and a hydraulic oil port (6); the control shaft of the miniature bidirectional gear pump (17) is connected with a servo motor (18), the servo motor (18) is electrically connected with a controller (19), one oil port of the miniature bidirectional gear pump (17) is connected with a top oil port (21) of a differential pressure matching type bidirectional flow control valve (20), and the other oil port of the miniature bidirectional gear pump (17) is connected with a middle oil port (22) of the differential pressure matching type bidirectional flow control valve (20) through a two-position two-way electromagnetic valve (16);
An upper piston (4) is arranged in an upper cavity of the bidirectional flow control valve (20), the upper piston (4) divides the upper cavity into an upper oil cavity (2) positioned above and an upper lower oil cavity (7) positioned below, an annular groove is formed in the inner wall of the middle of the upper cavity and is used as an upper sinking cutting groove (3), the upper oil cavity (2) and the upper sinking cutting groove (3) are communicated through an upper valve body inner oil duct (23) arranged in the valve body, and an upper spring (1) is connected between the upper piston (4) and the inner top surface of the upper cavity; a lower piston (11) is arranged in a lower cavity of the bidirectional flow control valve (20), the lower piston (11) divides the lower cavity into a lower upper oil cavity (9) positioned above and a lower oil cavity (25) positioned below, an annular groove is formed in the middle inner wall of the lower cavity and is used as a sinking cutting groove (10), the lower upper oil cavity (9) and the sinking cutting groove (10) are communicated through a lower valve body inner oil duct (24) arranged in the valve body, and a lower spring (14) is connected between the lower piston (11) and the inner bottom surface of the lower cavity; the elastic force of the upper spring (1) is larger than that of the lower spring (14); an intermediate cone valve (8) is fixedly connected between the upper piston (4) and the lower piston (11), and the conical surface of the intermediate cone valve (8) is used for being connected with the step surface between the upper cavity and the lower cavity in the valve body in a matched mode.
2. The differential pressure matched bidirectional high flow hydraulic control unit according to claim 1, wherein: the outer edges of the bottom surfaces of the upper piston (4) and the lower piston (11) are provided with notch grooves serving as throttling grooves; the throttling groove of the upper piston (4) is always communicated with the upper sinking cutting groove (3), and the throttling groove of the lower piston (11) is always communicated with the sinking cutting groove (10).
3. The differential pressure matched bidirectional high flow hydraulic control unit according to claim 2, wherein: the axial groove width of the upper undercut groove (3) is smaller than the actual contact thickness of the upper piston (4) and the upper cavity inner wall, and the axial groove width of the undercut groove (10) is smaller than the actual contact thickness of the lower piston (11) and the lower cavity inner wall.
4. The differential pressure matched bidirectional high flow hydraulic control unit according to claim 1, wherein: the top oil port (21) and the middle oil port (22) are used as internal flow ports of the hydraulic large-flow control unit, the hydraulic oil port (6) and the bottom oil port (13) are used as external flow ports of the hydraulic large-flow control unit, the hydraulic oil port (6) is connected with a load, and the bottom oil port (13) is connected with an oil tank; the flow rate between the tank and the hydraulic load is greater than the operating flow rate of the bi-directional gear pump (17).
5. The differential pressure matched bidirectional high flow hydraulic control unit according to claim 1, wherein: an upper throttling channel (5) is formed between the throttling groove on the bottom surface of the upper piston (4) and the lower edge of the upper sinking cutting groove (3), and a lower throttling channel (12) is formed between the throttling groove on the bottom surface of the lower piston (11) and the lower edge of the sinking cutting groove (10); the upper piston (4), the lower piston (11) and the middle cone valve (8) are coaxially connected to form a valve core, and the valve core moves up and down along the axial direction in the upper cavity and the lower cavity to drive the upper throttling channel (5) and the lower throttling channel (12) to increase and decrease, so that the flow regulation and control are realized.
6. A differential pressure matching type bidirectional high-flow hydraulic control method applied to any one of claims 1 to 5, which is characterized in that:
a) When high-pressure oil enters the bottom oil port (13), the hydraulic oil port (6) is connected with a low-pressure oil way, the high-pressure oil enters the lower oil cavity (25) at the lower part, the valve core is pushed to move upwards, the middle cone valve (8) is opened, and the upper oil cavity (7) is communicated with the upper oil cavity (9) at the lower part; simultaneously, the controller (19) opens the two-position two-way electromagnetic valve (16) to control the two-way gear pump (17) to pump hydraulic oil into the upper oil cavity (2) from the upper lower oil cavity (7), and increases the oil pressure in the upper oil cavity (2) so that the downward pressure difference borne by the upper piston (4) is increased, and the valve core is subjected to the thrust of the upward high-pressure oil and the downward pressure caused by the suction of the two-way gear pump (17); the rotating speed of the bidirectional gear pump is regulated, so that the upward differential pressure force born by the lower piston (11) and the downward differential pressure force born by the upper piston (4) are balanced, namely the valve core reaches an equilibrium position, and the equilibrium position is determined by the flow required by the system;
at the moment, the flow from the bottom oil port (13) to the hydraulic oil port (6) is positively controlled by the miniature bidirectional gear pump (17), namely, the flow discharged by the bidirectional gear pump (17) is increased, the downward pressure difference force applied to the upper piston (4) is increased, the upward pressure difference force applied to the lower piston (11) is unchanged, the valve core is lowered and reaches the position of pressure difference force balance again, the throttling area of the upper throttling channel (5) is reduced, and the throttling area of the lower throttling channel (12) is synchronously reduced, so that the flow of system overcurrent is also reduced;
Or reverse control is realized according to the reverse direction of the forward control;
b) When the hydraulic oil port (6) is filled with high-pressure oil, the bottom oil port (13) is connected with a low-pressure oil way; initially, the pressure difference between the upper lower oil cavity (7) and the lower upper oil cavity (9) can cause the middle cone valve (8) to be subjected to downward pressure difference force, and when the controller (19) opens the two-position two-way electromagnetic valve (16) and controls the two-way gear pump (17) to pump hydraulic oil from the upper oil cavity (2) into the upper lower oil cavity (7); in the process, the oil pressure in the upper oil cavity (2) is reduced by the suction of the bidirectional gear pump (17), and the pressure in the lower oil cavity (7) is unchanged, so that the upper piston (4) is subjected to upward pressure difference force;
when the rotating speed of the bidirectional gear pump (17) reaches high enough speed and the flow rate reaches high enough speed, the differential pressure force born by the upper piston (4) is larger than that born by the middle cone valve (8), the valve core is pushed to move upwards, the middle cone valve (8) is opened, and the communication between the upper lower oil cavity (7) and the lower upper oil cavity (9) is opened; the rotating speed of the bidirectional gear pump (17) is regulated, so that the differential pressure forces on the upper piston and the lower piston of the valve core are balanced, and finally the valve core reaches the balance position; at the moment, oil flows from the hydraulic oil port (6) through the lower upper oil cavity (9), the oil duct (24) and the undercut groove (10), and then flows into the bottom oil port (13) through the lower throttling channel (12) and the lower oil cavity (25);
At this time, the flow rate from the hydraulic oil port (6) to the bottom oil port (13) is positively controlled by a miniature bidirectional gear pump (17): the flow discharged by the bidirectional gear pump (17) is increased, the upward pressure difference force applied to the upper piston (4) is increased, the valve core is lifted, the throttling area of the upper throttling channel (5) is increased, and the throttling area of the lower throttling channel (12) is synchronously increased, so that the flow of the system overcurrent is also increased;
or reverse control is performed in accordance with the reverse of the above-described forward control.
7. The differential pressure matched bidirectional high-flow hydraulic control method according to claim 6, wherein the method comprises the following steps: said B) is replaced by the following C):
c) In the system oil way, a second two-position two-way electromagnetic valve (15) is added, one oil port of the second two-position two-way electromagnetic valve (15) is connected between the oil way of the two-way gear pump (17) and the two-position two-way electromagnetic valve (16), and the other oil port is connected with the bottom oil port (13) of the two-way flow control valve (20);
when the hydraulic oil port (6) is filled with high-pressure oil, the bottom oil port (13) is connected with a low-pressure oil way, and initially, the pressure difference between the upper lower oil cavity (7) and the lower upper oil cavity (9) can cause the middle cone valve (8) to be subjected to downward pressure difference force, at the moment, the controller (19) closes the two-position two-way electromagnetic valve (16), opens the second two-position two-way electromagnetic valve (15) and simultaneously controls the two-way gear pump (17) to pump hydraulic oil out of the upper oil cavity (2) and pump the hydraulic oil into the lower oil cavity (25); in the process, the oil pressure in the upper oil cavity (2) is reduced by the suction of the bidirectional gear pump (17), and the pressure in the upper lower oil cavity (7) is unchanged, so that the upper piston (4) is subjected to upward pressure difference force;
When the rotating speed of the bidirectional gear pump (17) reaches high enough speed/flow reaches high enough speed, the differential pressure force born by the upper piston (4) is larger than that born by the middle cone valve (8), the valve core is pushed to move upwards, the middle cone valve (8) is opened, and the communication between the upper lower oil cavity (7) and the lower upper oil cavity (9) is opened; the rotating speed, namely the flow rate, of the bidirectional gear pump (17) is regulated, and finally, the differential pressure forces borne by the upper piston and the lower piston of the valve core are balanced, so that the valve core reaches the balance position; the oil flows from the hydraulic oil port (6) through the lower upper oil cavity (9), the oil duct (24) and the undercut groove (10), and then flows into the bottom oil port (13) through the lower throttling channel (12) and the lower oil cavity (25);
at this time, the flow rate from the hydraulic oil port (6) to the bottom oil port (13) is positively controlled by a miniature bidirectional gear pump (17): namely, the flow discharged by the bidirectional gear pump (17) is increased, the upward pressure difference force applied to the upper piston (4) is increased, the valve core is lifted, the throttling area of the upper throttling channel (5) is increased, and the throttling area of the lower throttling channel (12) is also increased synchronously, so that the flow of the overflow of the system from the hydraulic oil port (6) to the bottom oil port (13) is also increased;
or reverse control is performed in accordance with the reverse of the above-described forward control.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AR227747A1 (en) * | 1981-09-14 | 1982-11-30 | Deere & Co | IMPROVED HYDRAULIC CONTROL VALVE |
| JP2001323902A (en) * | 2000-05-16 | 2001-11-22 | Hitachi Constr Mach Co Ltd | Hydraulic driven device |
| CN101216052A (en) * | 2008-01-09 | 2008-07-09 | 浙江大学 | Rotating speed variable driving shield cutterhead energy-saving hydraulic control system |
| WO2013078878A1 (en) * | 2011-11-29 | 2013-06-06 | 国网电力科学研究院 | Comprehensive regulation device for small speed-regulator based on integrated hydraulic pressure technology |
| WO2016141638A1 (en) * | 2015-03-06 | 2016-09-15 | 洛阳市伟林液压机械有限公司 | Operation method for tractor clutch operation device having hydraulic assistance |
| CN107120324A (en) * | 2017-04-24 | 2017-09-01 | 登派液压技术（上海）有限公司 | Gear pump control hydraulic control system of bender |
-
2021
- 2021-05-21 CN CN202110557111.2A patent/CN113323933B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AR227747A1 (en) * | 1981-09-14 | 1982-11-30 | Deere & Co | IMPROVED HYDRAULIC CONTROL VALVE |
| JP2001323902A (en) * | 2000-05-16 | 2001-11-22 | Hitachi Constr Mach Co Ltd | Hydraulic driven device |
| CN101216052A (en) * | 2008-01-09 | 2008-07-09 | 浙江大学 | Rotating speed variable driving shield cutterhead energy-saving hydraulic control system |
| WO2013078878A1 (en) * | 2011-11-29 | 2013-06-06 | 国网电力科学研究院 | Comprehensive regulation device for small speed-regulator based on integrated hydraulic pressure technology |
| WO2016141638A1 (en) * | 2015-03-06 | 2016-09-15 | 洛阳市伟林液压机械有限公司 | Operation method for tractor clutch operation device having hydraulic assistance |
| CN107120324A (en) * | 2017-04-24 | 2017-09-01 | 登派液压技术（上海）有限公司 | Gear pump control hydraulic control system of bender |
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|---|---|
| CN113323933A (en) | 2021-08-31 |
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