Gas flow control method and engine system

Abstract

The application discloses a gas flow control method and an engine system, and relates to the technical field of engine intake flow control. The gas flow control method comprises the following steps: acquiring the pressure of a front chamber of a Laval tube and the pressure of an outlet; calculating the ratio of the pressure of the front chamber to the pressure of the outlet; judging whether the ratio of the pressure of the front chamber to the pressure of the outlet is within a target pressure ratio range; if yes, decoupling the outlet and a pressure adjusting mechanism for adjusting the pressure of the front chamber through a pressure decoupling module; if not, coupling the outlet and the pressure adjusting mechanism through the pressure decoupling module, and controlling the flow direction of the gas, so that the ratio of the pressure of the front chamber to the pressure of the outlet reaches the target pressure ratio range, and the gas of the Laval tube reaches a supersonic state, the pressure of the front chamber is stable or is adjusted according to the fluctuation of the engine intake pipe pressure, and the gas flow control precision is higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine gas flow control, and particularly relates to a gas flow control method and an engine system. BACKGROUND

[0002] With the increasingly stringent requirements for engine emissions, it is urgent to accurately control the intake process of the engine. The flow valve is connected with the intake pipe of the engine, and can realize controllable and accurate and stable engine intake control.

[0003] At present, the flow valve is usually provided with two-stage adjusting mechanisms, a first-stage adjusting mechanism is used for adjusting the pressure in the valve cavity, and a second-stage adjusting mechanism controls the displacement of the valve core, so as to control the throat cross-sectional area of the Venturi tube, achieve the purpose of changing the gas flow area, make the gas passing through the Venturi tube reach the supersonic state through the adjustment of the pressure in the cavity, and control the gas flow through the control of the throat cross-sectional area of the Venturi tube. However, the first-stage adjusting mechanism uses a first-stage motor actuator, which increases the product cost, and also interferes with the magnetic field of the feedback system of the second-stage motor actuator, thereby affecting the control accuracy of the second-stage motor actuator. In the prior art, in order to solve the above problems, a pressure adjusting mechanism driven by a mechanical mechanism is arranged to keep the pressure parameter in the cavity stable, and the gas pressure at the outlet of the Venturi tube directly feeds back to the pressure adjusting mechanism. However, the gas pressure at the outlet of the Venturi tube is affected by the conventional pressure fluctuation (the pressure fluctuation does not occur in the engine intake pipe) under the steady-state working condition, and fluctuation occurs, and then the fluctuation is also fed back to the adjusting control of the pressure adjusting mechanism, so that the gas in the cavity is disturbed, the disturbed gas causes pressure fluctuation, and the position of the valve rod of the electromagnetic actuator needs to be controlled to compensate for the flow through the control of the throat cross-sectional area of the Venturi tube, which affects the flow control accuracy of the system and also puts forward higher requirements for control. SUMMARY

[0004] The purpose of the present application is to provide a gas flow control method and an engine system, so as to keep the inlet pressure of the Laval tube stable under the steady-state working condition, and adjust the inlet pressure of the Laval tube according to the outlet pressure of the Laval tube under the transient change working condition, so that the gas flow control accuracy is higher.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0006] The gas flow control method is used for controlling the intake flow of an engine, the intake pipe of the engine is connected with a flow valve, the flow valve comprises a valve body, a Laval tube and a pressure decoupling module, the intake port of the valve body is communicated with a front chamber through a pressure adjusting mechanism, the inlet of the Laval tube is communicated with the front chamber, the outlet of the Laval tube is communicated with the intake pipe of the engine, the pressure decoupling module is arranged between the outlet and the pressure adjusting mechanism, and the gas flow control method comprises the following steps:

[0007] acquiring the pressure of the front chamber and the pressure of the outlet, and calculating the ratio of the pressure of the front chamber to the pressure of the outlet;

[0008] judging whether the ratio of the pressure of the front chamber to the pressure of the outlet is within a target pressure ratio range;

[0009] if yes, decoupling the outlet from the pressure regulating mechanism through the pressure decoupling module; if no, coupling the outlet with the pressure regulating mechanism through the pressure decoupling module, and controlling the flow direction of the gas so as to make the ratio of the pressure of the front chamber to the pressure of the outlet reach the target pressure ratio range.

[0010] As an optional solution of the gas flow control method, the pressure decoupling module comprises a first electromagnetic valve, a first one-way valve, a second electromagnetic valve and a second one-way valve, the first gas feedback passage and the second gas feedback passage are arranged in parallel between the outlet and the pressure regulating mechanism, the first electromagnetic valve and the first one-way valve are arranged in the first gas feedback passage, and the second electromagnetic valve and the second one-way valve are arranged in the second gas feedback passage.

[0011] controlling the first electromagnetic valve and the second electromagnetic valve to be closed, so as to decouple the outlet from the pressure regulating mechanism; controlling one of the first electromagnetic valve and the second electromagnetic valve to be opened, so as to couple the outlet with the pressure regulating mechanism.

[0012] As an optional solution of the gas flow control method, the target pressure ratio range is between a set pressure upper limit value and a set pressure lower limit value, and the flow direction of the gas is controlled according to the relationship between the ratio of the pressure of the front chamber to the pressure of the outlet and the set pressure upper limit value or the set pressure lower limit value.

[0013] As an optional solution of the gas flow control method, if the ratio of the pressure of the front chamber to the pressure of the outlet is greater than the set pressure upper limit value, the outlet is coupled with the pressure regulating mechanism through the pressure decoupling module, and the gas is controlled to flow from the pressure regulating mechanism to the outlet.

[0014] As an optional solution of the gas flow control method, the pressure regulating mechanism comprises a pressure regulator valve chamber and a pressure regulator spring chamber separated by a diaphragm, and a pressure regulator valve is arranged in the pressure regulator valve chamber to control the opening degree of the gas inlet.

[0015] When the ratio of the pressure of the front chamber to the pressure of the outlet is greater than the upper limit of the set pressure, the second electromagnetic valve is controlled to open, the pressure regulator spring chamber is communicated with the outlet through the second gas feedback passage, the gas in the pressure regulator spring chamber flows to the outlet through the second check valve under the action of the gas pressure of the outlet, the pressure of the pressure regulator spring chamber decreases, the diaphragm drives the pressure regulator valve to move towards the pressure regulator spring chamber, the opening of the air inlet decreases, and then the pressure of the front chamber decreases, until the ratio of the pressure of the front chamber to the pressure of the outlet reaches the target pressure ratio range, the second electromagnetic valve is controlled to close.

[0016] As an optional solution of the gas flow control method, if the ratio of the pressure of the front chamber to the pressure of the outlet is less than the lower limit of the set pressure, the outlet is coupled with the front chamber through the pressure decoupling module, and the gas flows from the outlet to the pressure regulating mechanism is controlled.

[0017] As an optional solution of the gas flow control method, when the ratio of the pressure of the front chamber to the pressure of the outlet is less than the lower limit of the set pressure, the first electromagnetic valve is controlled to open, the gas of the outlet flows to the pressure regulator spring chamber through the first check valve, the pressure regulator valve chamber is compressed by the diaphragm, the diaphragm drives the pressure regulator valve to move away from the pressure regulator spring chamber, the opening of the air inlet increases, and then the pressure of the front chamber increases, until the ratio of the pressure of the front chamber to the pressure of the outlet reaches the target pressure ratio range, the first electromagnetic valve is controlled to close.

[0018] As an optional solution of the gas flow control method, the pressure of the front chamber is obtained by a first pressure sensor, and the pressure of the outlet is obtained by a second pressure sensor or by subtracting the pressure loss from the pressure of the intake pipe of the engine.

[0019] As an optional solution of the gas flow control method, the pressure of the outlet is adjusted by adjusting the gas flow of the outlet, and the gas flow of the outlet is adjusted by adjusting the throat cross-sectional area of the Laval tube.

[0020] An engine system comprising an intake pipe of an engine and a flow valve, the flow valve controls the intake flow of the engine by using the gas flow control method according to any one of the above solutions.

[0021] The beneficial effects of the present application are as follows:

[0022] The gas flow control method provided by the application, by obtaining the pressure of the front chamber of the Laval tube and the pressure of the outlet, calculating the ratio of the pressure of the front chamber to the pressure of the outlet, judging whether the ratio of the pressure of the front chamber to the outlet is within the target pressure ratio range, if yes, it means that the pressure of the front chamber at this time can make the gas of the Laval tube reach the supersonic state, and the pressure of the front chamber needs to be kept stable, in order to avoid the influence of the normal pressure fluctuation of the outlet on the pressure of the front chamber, the outlet is decoupled from the pressure regulating mechanism for regulating the pressure of the front chamber through the pressure decoupling module. If not, it means that this is a transient change condition, and the pressure of the front chamber needs to be adjusted with the outlet pressure to make the gas of the Laval tube reach the supersonic state, the outlet is coupled with the pressure regulating mechanism through the pressure decoupling module, and the flow direction of the gas is controlled, so that the ratio of the pressure of the front chamber to the pressure of the outlet reaches the target pressure ratio range, and then the gas of the Laval tube reaches the supersonic state. The gas flow control method provided by the application can decouple or couple the outlet from the pressure regulating mechanism through the pressure decoupling module according to whether the ratio of the pressure of the front chamber to the pressure of the outlet reaches the target pressure range, so as to ensure that the pressure of the front chamber is stable or adjusted with the engine inlet pipe pressure fluctuation, so that the gas flow control precision is higher.

[0023] The engine system provided by the application connects the engine inlet pipe with the outlet of the flow valve, and adopts the above-mentioned gas flow control method to control the gas flow entering the engine, so as to realize precise and stable control of the engine inlet. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the flow valve provided by the embodiment of the application;

[0025] Figure 2 is a sectional view of the flow valve provided by the embodiment of the application Figure 1 ;

[0026] Figure 3 is an exploded view of the flow valve provided by the embodiment of the application;

[0027] Figure 4 is a sectional view of the flow valve provided by the embodiment of the application Figure 1 ;

[0028] Figure 5 is an exploded view of the pressure decoupling module provided by the embodiment of the application;

[0029] Figure 6 is a structural schematic diagram of the outlet connected with the pressure regulating mechanism through the pressure decoupling module provided by the embodiment of the application;

[0030] Figure 7 is a sectional view of the flow valve provided by the embodiment of the application Figure 2 ;

[0031] Figure 8 is a cross section of a flow valve provided by an embodiment of the present application Figure 2 ;

[0032] Figure 9 is a structural schematic diagram of a cooperation between a Laval tube and a valve rod provided by an embodiment of the present application

[0033] Figure 10 is a working principle schematic diagram of a pressure decoupling module provided by an embodiment of the present application

[0034] Figure 11 is a flow chart of a gas flow control method provided by an embodiment of the present application

[0035] In the drawings:

[0036] 1, valve body; 11, gas inlet; 12, front chamber; 13, first gas feedback passage; 14, second gas feedback passage; 15, gas feedback inlet; 16, gas feedback outlet

[0037] 2, pressure regulating mechanism; 21, pressure regulator valve; 22, diaphragm; 23, spring

[0038] 3, Laval tube; 31, inlet; 32, outlet

[0039] 4, pressure decoupling module; 41, first electromagnetic valve; 42, first one-way valve; 43, second electromagnetic valve; 44, second one-way valve

[0040] 5, electromagnetic actuator

[0041] 6, valve rod

[0042] 7, controller DETAILED DESCRIPTION

[0043] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0044] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 a limitation of the present application. In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0045] Unless otherwise clearly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" should be understood broadly, for example, it can be fixed connection, or detachable connection; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through 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.

[0046] Unless otherwise clearly specified and limited, "on" or "under" of the first feature to the second feature can include that the first feature and the second feature are in direct contact, or the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0047] The technical scheme of the present application will be further illustrated below in conjunction with the drawings and through specific embodiments.

[0048] As Figures 1-10As shown, the embodiment provides an engine system, which comprises an intake pipe of an engine and a flow valve connected with the intake pipe of the engine for controlling the intake flow of the engine. The flow valve comprises a valve body 1, a Laval tube 3 and a pressure decoupling module 4. The valve body 1 is provided with an intake port 11 and a front chamber 12. The intake port 11 is communicated with the front chamber 12 through a pressure adjusting mechanism 2. The pressure adjusting mechanism 2 is used for adjusting the pressure of the front chamber 12. The front chamber 12 is provided with a first pressure sensor for detecting the pressure of the front chamber 12. The Laval tube 3 comprises an inlet 31 and an outlet 32. The inlet 31 is communicated with the front chamber 12. The outlet 32 is provided with a second pressure sensor for detecting the pressure of the outlet 32. The engine intake pipe is connected with the outlet 32 to realize the precise control of the intake flow of the engine. In other embodiments, since the engine intake pipe is provided with the pressure sensor, the outlet 32 can also not be provided with the pressure sensor. The pressure of the outlet 32 can be obtained according to the pressure of the engine intake pipe minus the pressure loss. The pressure loss is obtained according to experience or test.

[0049] Specifically, the pressure adjusting mechanism 2 comprises a pressure regulator valve 21, a diaphragm 22 and a spring 23. The valve body 1 is provided with a pressure regulating chamber. The diaphragm 22 is connected with the pressure regulator valve 21 and the spring 23 respectively on two sides to separate the pressure regulating chamber into a pressure regulator valve chamber and a pressure regulator spring chamber. The pressure regulator valve chamber is communicated with the intake port 11 and the front chamber 12 through the pressure regulator valve 21. The gas pressure change in the pressure regulator spring chamber can drive the pressure regulator valve 21 to move through the diaphragm 22 to adjust the opening degree of the intake port 11 to adjust the gas flow entering the front chamber 12. The gas enters the pressure regulating chamber in the valve body 1 from the intake port 11 of the valve body 1. The pressure adjusting mechanism 2 is arranged in the pressure regulating chamber to keep the pressure parameter of the front chamber 12 stable through the pressure adjusting mechanism 2.

[0050] The flow valve further comprises an electromagnetic actuator 5 and a valve rod 6. The valve rod 6 is connected with the Laval tube 3 through the front chamber 12. The electromagnetic actuator 5 drives the valve rod 6 to move to adjust the throat cross-sectional area of the Laval tube 3 to control the gas flow of the outlet 32.

[0051] Optionally, the electromagnetic actuator 5 is a motor.

[0052] Through the cooperation of the pressure adjusting mechanism 2 and the electromagnetic actuator 5, the pressure ratio of the inlet 31 and the outlet 32 of the Laval tube 3 is kept in the condition that the gas in the Laval tube 3 can reach the supersonic state. In the embodiment, only one motor is used. The pressure adjusting mechanism 2 adopts a mechanical pressure regulating mechanism to cancel the first motor or electromagnetic actuator. Through the mechanical pressure regulating structure, the structure is simple, the continuous flow valve can more simply realize the precise control of the gas flow, and the cost of the product is reduced.

[0053] However, since the pressure of the outlet 32 is affected by the fluctuation of the engine intake pipe pressure, the outlet 32 is usually connected with the pressure regulator spring chamber through a gas feedback passage, so that the pressure of the gas in the outlet 32 is used as the driving factor of the pressure regulator valve 21 to jointly regulate the pressure of the front chamber 12 with the pressure regulating mechanism 2, the pressure of the front chamber 12 is linearly related to the pressure of the outlet 32, and the pressure difference between the inlet 31 and the outlet 32 of the Laval nozzle 3 can be kept constant, and the pressure of the front chamber 12 is adjusted according to the fluctuation of the pressure of the outlet 32, so that when the pressure of the outlet 32 decreases, the pressure of the front chamber 12 also decreases, and the pressure ratio of the inlet 31 to the outlet 32 of the Laval nozzle 3 can be kept in the condition that the gas in the Laval nozzle 3 is in a supersonic state. When the pressure of the outlet 32 increases, the pressure of the inlet 31 of the Laval nozzle 3 also increases, so that the pressure ratio of the inlet 31 to the outlet 32 of the Laval nozzle 3 can be kept in the condition that the gas in the Laval nozzle 3 is in a supersonic state.

[0054] However, in the steady state working condition, the normal pressure fluctuation of the outlet 32 (no pressure fluctuation of the engine intake pipe) will also be fed back to the adjustment control of the pressure regulating mechanism 2, causing the disturbance of the gas in the front chamber 12, and the disturbed gas will cause the pressure fluctuation of the front chamber 12. In the prior art, the electromagnetic actuator 5 drives the valve rod 6 to move to control the gas flow compensation of the throat area of the Laval nozzle 3, but the flow control accuracy is affected.

[0055] In the embodiment, the pressure decoupling module 4 is arranged between the outlet 32 and the pressure regulating mechanism 2, the pressure decoupling module 4 can selectively decouple or couple the outlet 32 and the pressure regulating mechanism 2, and when the outlet 32 and the pressure regulating mechanism 2 are coupled, the flow direction of the gas can be controlled. By arranging the pressure decoupling module 4, the outlet 32 and the pressure regulating mechanism 2 can be selectively decoupled or coupled according to different working conditions, and when the outlet 32 and the pressure regulating mechanism 2 are coupled, the flow direction of the gas can be controlled, so that the pressure ratio of the front chamber 12 to the outlet 32 is within the target pressure ratio range, and the control accuracy of the gas flow is improved.

[0056] Specifically, the first gas feedback passage 13 and the second gas feedback passage 14 are arranged in parallel between the outlet 32 and the pressure regulator spring chamber, the pressure decoupling module 4 includes a first electromagnetic valve 41, a first one-way valve 42, a second electromagnetic valve 43 and a second one-way valve 44, the first electromagnetic valve 41 and the first one-way valve 42 are arranged in the first gas feedback passage 13, the first one-way valve 42 is used for one-way conduction of the outlet 32 to the pressure regulator spring chamber, the second electromagnetic valve 43 and the second one-way valve 44 are arranged in the second gas feedback passage 14, and the second one-way valve 44 is used for one-way conduction of the pressure regulator spring chamber to the outlet 32.

[0057] As shown in FIG. 1, the pressure regulating mechanism 2 includes a pressure regulating valve 21, a pressure regulating spring chamber 22, a pressure regulating spring 23 and a pressure regulating spring guide 24. Figure 6As shown, the valve body 1 is further provided with a gas feedback inlet 15 and a gas feedback outlet 16, the gas feedback inlet 15 is located in the cavity where the outlet 32 is located, the gas feedback outlet 16 is located in the pressure regulator spring cavity, one end of the first gas feedback passage 13 and one end of the second gas feedback passage 14 are in communication with the gas feedback inlet 15, the other end of the first gas feedback passage 13 and the other end of the second gas feedback passage 14 are in communication with the gas feedback outlet 16, the gas in the cavity of the outlet 32 enters the first gas feedback passage 13 or the second gas feedback passage 14 through the gas feedback inlet 15, and then enters the pressure regulator spring cavity through the gas feedback outlet 16, so as to refresh the highest value of the front chamber 12 with the gas peak value of the outlet 32, or refresh the lowest value of the front chamber 12 with the gas valley value of the outlet 32.

[0058] The engine system further comprises a controller 7, the first pressure sensor and the second pressure sensor are signal connected with the controller 7, the first electromagnetic valve 41 and the second electromagnetic valve 43 are electrically connected with the controller 7, the first pressure sensor sends the detected pressure of the front chamber 12 to the controller 7, and the second pressure sensor sends the detected pressure of the outlet 32 to the controller 7, the pressure of the front chamber 12 is approximately equal to the pressure of the inlet 31 of the Laval tube 3, the controller 7 calculates the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 according to the received pressure of the front chamber 12 and the pressure of the outlet 32, and compares it with the target pressure ratio range, the target pressure ratio range is the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 when the gas in the Laval tube 3 is in a supersonic state, and the controller 7 takes the target pressure ratio range as the target for closed-loop regulation, keeps the high response and rapid feedback function of the pressure of the front chamber 12 to the pressure of the outlet 32 under necessary working conditions, so that the flow valve can be accurately controlled under the target of the target pressure ratio range.

[0059] Specifically, when the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 calculated by the controller 7 is in the target pressure ratio range, the controller 7 controls the first electromagnetic valve 41 and the second electromagnetic valve 43 to be closed, and the normal pressure fluctuation of the outlet 32 will not affect the pressure of the front chamber 12. When the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is not in the target pressure ratio range, it indicates that the gas in the Laval tube 3 has not formed a supersonic flow, and the pressure of the outlet 32 needs to be taken as the actuating factor of the pressure regulator valve 21 to adjust the pressure of the front chamber 12 together with the pressure regulating mechanism 2, so that the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 reaches the target pressure ratio range.

[0060] When the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is less than the set pressure lower limit value, it indicates that the pressure of the front chamber 12 is small, and the pressure of the front chamber 12 needs to be increased. At this time, the controller 7 controls the first electromagnetic valve 41 to open, so that the gas of the outlet 32 can enter the pressure regulator spring chamber through the first one-way valve 42. The pressure peak of the gas of the outlet 32 constantly refreshes the maximum value of the pressure of the front chamber 12, and the pressure of the front chamber 12 constantly rises, until the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 reaches the target pressure ratio range, and the first electromagnetic valve 41 is closed, so that the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 reaches the target pressure ratio range.

[0061] When the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is greater than the set pressure upper limit value, it indicates that the pressure of the front chamber 12 is large, and the pressure of the front chamber 12 needs to be reduced. At this time, the controller 7 controls the second electromagnetic valve 43 to open, so that the pressure regulator spring chamber is communicated with the outlet 32 through the second gas feedback passage 14. Under the action of the gas pressure of the outlet 32, the trough of the gas pressure of the outlet 32 constantly refreshes the minimum value of the pressure of the front chamber 12, so that the pressure of the front chamber 12 decreases, until the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 reaches the target pressure ratio range, and the second electromagnetic valve 43 is controlled to be closed, so that the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 reaches the target pressure ratio range.

[0062] That is, the pressure decoupling module 4 provided in the embodiment, in the steady state, and when the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is in the target pressure ratio range, the first electromagnetic valve 41 and the second electromagnetic valve 43 are both closed, the gas feedback passage is disconnected, and the flow valve operates without feedback. In the transient state, the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is controlled through the gas feedback passage, and the target pressure ratio range is taken as the target for closed-loop control, so as to clearly adjust the direction and achieve the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 to a controllable state, so as to accurately control the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32, which is beneficial to more accurate flow control of the flow valve.

[0063] Further, the first electromagnetic valve 41 and the second electromagnetic valve 43 are both electromagnetic on-off valves or electromagnetic proportional valves. The electromagnetic on-off valve can control the on-off of the first gas feedback passage 13 and the second gas feedback passage 14, and the electromagnetic proportional valve can not only control the on-off of the first gas feedback passage 13 and the second gas feedback passage 14, but also control the flow of the gas, so as to further realize accurate control.

[0064] The electromagnetic valve and the one-way valve in the pressure decoupling module 4 are low in cost, and electromagnetic interference generated by setting two-stage electromagnetic mechanisms in the prior art is reduced or avoided, and in addition, the gas feedback passage in the embodiment has a pressure much smaller than the pressure of the gas inlet 11, and energy consumption is smaller.

[0065] In the flow valve provided by the embodiment, the mechanical structure is used in the pressure regulating mechanism 2 for pressure feedback control, and the one-way valve is used for guiding the direction of the gas, and for pressure regulating control, a simple electromagnetic valve driving control on-off can be used, which can greatly simplify the software and hardware design of the control logic and the driving circuit, reduce the failure items of the flow valve, and improve the reliability and robustness of the flow valve.

[0066] As shown in Figure 11 The embodiment further provides a gas flow control method, which is applied to the flow valve and includes the following steps.

[0067] S10, the pressure of the front chamber 12 and the pressure of the outlet 32 are obtained, and the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is calculated.

[0068] The pressure of the front chamber 12 is obtained by the first pressure sensor, and the pressure of the outlet 32 is obtained by the second pressure sensor or obtained by subtracting the pressure loss from the pressure of the engine intake pipe. The pressure of the front chamber 12 detected by the first pressure sensor and the pressure of the outlet 32 detected by the second pressure sensor are both sent to the controller 7, and the controller 7 calculates the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 according to the received pressure of the front chamber 12 and the pressure of the outlet 32.

[0069] The pressure of the front chamber 12 is regulated by the pressure regulating mechanism 2, the pressure of the outlet 32 is regulated by regulating the gas flow of the outlet 32, and the gas flow of the outlet is regulated by regulating the throat cross-sectional area of the Laval tube 3. Specifically, the electromagnetic actuator 5 drives the valve rod 6 to move, and regulates the throat cross-sectional area of the Laval tube 3, so as to control the gas flow of the outlet 32.

[0070] S20, it is judged whether the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is within the target pressure ratio range; if yes, S31 is executed; if no, S32 is executed.

[0071] S31, the outlet 32 is decoupled from the pressure regulating mechanism 2 by the pressure decoupling module 4.

[0072] When the position of the valve stem 6 is unchanged, that is, the throat area of the Laval tube 3 is unchanged, the pressure of the outlet 32 is affected by the fluctuation of the engine intake pipe pressure, in order to keep the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 within the target pressure ratio range, the pressure of the front chamber 12 is adjusted by the pressure regulating mechanism 2. The pressure regulating mechanism 2 includes a pressure regulator valve 21 connected by a diaphragm 22 and a spring 23, the spring 23 is located in the pressure regulator spring chamber, the outlet 32 is communicated with the pressure regulator spring chamber through a gas feedback passage, the normal pressure fluctuation of the outlet 32 affects the pressure of the front chamber 12, and further affects the pressure stability of the front chamber 12. Specifically, the inlet 11 is communicated with the front chamber 12 through the pressure regulator valve chamber, the pressure regulator valve 21 abuts against the inlet 11, the pressure change of the pressure regulator spring chamber affects the opening of the inlet 11, and further affects the gas flow entering the front chamber 12 through the inlet 11 and the pressure regulator valve chamber, under the condition that the volume and temperature of the front chamber 12 are unchanged, the greater the gas flow entering the front chamber 12, the greater the pressure in the front chamber 12, that is, the greater the pressure of the inlet 31.

[0073] Specifically, the pressure decoupling module 4 includes a first electromagnetic valve 41, a first one-way valve 42, a second electromagnetic valve 43 and a second one-way valve 44, the first gas feedback passage 13 and the second gas feedback passage 14 are arranged in parallel between the outlet 32 and the pressure regulating mechanism 2, the first electromagnetic valve 41 and the first one-way valve 42 are arranged in the first gas feedback passage 13, and the second electromagnetic valve 43 and the second one-way valve 44 are arranged in the second gas feedback passage 14. Controlling the first electromagnetic valve 41 and the second electromagnetic valve 43 to be closed can decouple the outlet 32 from the pressure regulating mechanism 2.

[0074] When the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is within the target pressure ratio range, the first electromagnetic valve 41 and the second electromagnetic valve 43 are controlled to be closed, that is, the first gas feedback passage 13 and the second gas feedback passage 14 are disconnected, so as to decouple the outlet 32 from the pressure regulating mechanism 2.

[0075] When the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 is within the target pressure ratio range, and in the steady state working condition, in order to avoid the normal pressure fluctuation of the outlet 32 affecting the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32, the outlet 32 is decoupled from the pressure regulator spring chamber through the pressure decoupling module 4, the controller 7 controls the first electromagnetic valve 41 and the second electromagnetic valve 43 to be closed, so as to decouple the outlet 32 from the pressure regulator spring chamber, and the gas pressure in the front chamber 12 is stable in the steady state working condition.

[0076] S32, the outlet 32 is coupled with the pressure regulating mechanism 2 through the pressure decoupling module 4, and the flow direction of the gas is controlled, so that the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 reaches the target pressure ratio range.

[0077] The opening of one of the first electromagnetic valve 41 and the second electromagnetic valve 43 can couple the outlet 32 with the pressure regulating mechanism 2. The target pressure ratio range is between the set pressure upper limit value and the set pressure lower limit value, and the flow direction of the gas is controlled according to the relationship between the ratio of the pressure in the front chamber 12 to the pressure in the outlet 32 and the set pressure upper limit value or the set pressure lower limit value.

[0078] Specifically, if the ratio of the pressure in the front chamber 12 to the pressure in the outlet 32 is greater than the set pressure upper limit value, the outlet 32 is coupled with the pressure regulating mechanism 2 through the pressure decoupling module 4, and the gas flows from the pressure regulating mechanism 2 to the outlet 32. Further, when the ratio of the pressure in the front chamber 12 to the pressure in the outlet 32 is greater than the set pressure upper limit value, the second electromagnetic valve 43 is controlled to be opened, and the pressure regulator spring chamber is communicated with the outlet 32 through the second gas feedback passage 14. Under the action of the gas pressure in the outlet 32, the gas in the pressure regulator spring chamber flows to the outlet 32 through the second one-way valve 44, the pressure in the pressure regulator spring chamber decreases, the diaphragm 22 drives the pressure regulator valve 21 to move towards the pressure regulator spring chamber, the opening degree of the inlet port 11 decreases, and then the pressure in the front chamber 12 decreases, until the ratio of the pressure in the front chamber 12 to the pressure in the outlet 32 reaches the target pressure ratio range, and the second electromagnetic valve 43 is controlled to be closed.

[0079] If the ratio of the pressure in the front chamber 12 to the pressure in the outlet 32 is less than the set pressure lower limit value, the outlet 32 is coupled with the front chamber 12 through the pressure decoupling module 4, and the gas flows from the outlet 32 to the pressure regulating mechanism 2. Further, when the ratio of the pressure in the front chamber 12 to the pressure in the outlet 32 is less than the set pressure lower limit value, the first electromagnetic valve 41 is controlled to be opened, and the gas in the outlet 32 flows to the pressure regulator spring chamber through the first one-way valve 42, the diaphragm 22 compresses the pressure regulator valve chamber, and the diaphragm 22 drives the pressure regulator valve 21 to move away from the pressure regulator spring chamber, the opening degree of the inlet port 11 increases, and then the pressure in the front chamber 12 increases, until the ratio of the pressure in the front chamber 12 to the pressure in the outlet 32 reaches the target pressure ratio range, and the first electromagnetic valve 41 is controlled to be closed.

[0080] The gas flow control method provided by the embodiment can decouple or couple the outlet 32 with the pressure regulating mechanism 2 through the pressure decoupling module 4 according to different working conditions, ensure the stability of the pressure in the front chamber 12 or adjust the pressure in the front chamber 12 according to the change of the pressure in the engine inlet pipe, and make the gas flow control more accurate.

[0081] The embodiment provides an engine system, which adopts the gas flow control method to control the intake flow of the engine, and the engine intake pipe is connected with the outlet 32. The flow valve can selectively decouple or couple the outlet 32 and the front chamber 12 according to different working conditions, and when the outlet 32 is coupled with the front chamber 12, the flow direction of the gas is controlled, so that the pressure ratio of the front chamber 12 to the outlet 32 is within the target pressure ratio range, and the control precision of the gas flow is improved.

[0082] The above merely describes the preferred embodiments of the present application, and for those skilled in the art, the specific implementation manners and application scopes can be changed according to the idea of the present application, and the content of the description should not be understood as a limitation of the present application.

Claims

1. A gas flow control method for controlling the intake flow of an engine, the intake pipe of the engine being connected to a flow valve, characterized by, The flow valve comprises a valve body (1), a Laval tube (3) and a pressure decoupling module (4), an air inlet (11) of the valve body (1) is communicated with a front chamber (12) through a pressure regulating mechanism (2), an inlet (31) of the Laval tube (3) is communicated with the front chamber (12), an outlet (32) of the Laval tube (3) is communicated with an air inlet pipe of the engine, and the pressure decoupling module (4) is arranged between the outlet (32) and the pressure regulating mechanism (2); the pressure decoupling module (4) comprises a first electromagnetic valve (41), a first check valve (42), a second electromagnetic valve (43) and a second check valve (44), a first gas feedback passage (13) and a second gas feedback passage (14) are arranged in parallel between the outlet (32) and the pressure regulating mechanism (2), the first electromagnetic valve (41) and the first check valve (42) are arranged in the first gas feedback passage (13), and the second electromagnetic valve (43) and the second check valve (44) are arranged in the second gas feedback passage (14); the gas flow control method comprises the following steps: obtaining the pressure of the front chamber (12) and the pressure of the outlet (32), and calculating the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32); determining whether the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) is within a target pressure ratio range; if yes, controlling the first electromagnetic valve (41) and the second electromagnetic valve (43) to be closed, and decoupling the outlet (32) from the pressure regulating mechanism (2); if no, controlling one of the first electromagnetic valve (41) and the second electromagnetic valve (43) to be opened, coupling the outlet (32) with the pressure regulating mechanism (2), and controlling the flow direction of the gas, so that the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) is within the target pressure ratio range.

2. The gas flow control method according to claim 1, wherein The target pressure ratio range is between a set pressure upper limit value and a set pressure lower limit value, and the flow direction of the gas is controlled according to the relationship between the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) and the set pressure upper limit value or the set pressure lower limit value.

3. The gas flow control method according to claim 2, wherein If the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) is greater than the set pressure upper limit value, the outlet (32) is coupled with the pressure regulating mechanism (2) through the pressure decoupling module (4), and the gas flows from the pressure regulating mechanism (2) to the outlet (32).

4. The gas flow control method according to claim 3, wherein The pressure regulating mechanism (2) comprises a pressure regulator valve chamber and a pressure regulator spring chamber separated by a diaphragm (22), and a pressure regulator valve (21) for controlling the opening degree of the air inlet (11) is arranged in the pressure regulator valve chamber. When the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) is greater than the set pressure maximum limit, the second solenoid valve (43) is controlled to open, the pressure regulator spring chamber is connected to the outlet (32) through the second gas feedback passage (14), and under the action of the gas pressure of the outlet (32), the gas in the pressure regulator spring chamber flows to the outlet (32) through the second one-way valve (44), the pressure of the pressure regulator spring chamber decreases, the diaphragm (22) drives the pressure regulator valve (21) to move toward the pressure regulator spring chamber, the opening of the air inlet (11) decreases, and then the pressure of the front chamber (12) decreases, until the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) reaches within the target pressure ratio range, and the second solenoid valve (43) is controlled to close.

5. The gas flow control method according to claim 4, wherein If the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) is less than the set pressure minimum limit, the outlet (32) is coupled to the front chamber (12) through the pressure decoupling module (4), and the gas is controlled to flow from the outlet (32) to the pressure regulating mechanism (2).

6. The gas flow control method according to claim 5, wherein When the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) is less than the set pressure minimum limit, the first solenoid valve (41) is controlled to open, and the gas of the outlet (32) flows to the pressure regulator spring chamber through the first one-way valve (42), compresses the pressure regulator valve chamber through the diaphragm (22), and the diaphragm (22) drives the pressure regulator valve (21) to move away from the pressure regulator spring chamber, the opening of the air inlet (11) increases, and then the pressure of the front chamber (12) increases, until the ratio of the pressure of the front chamber (12) to the pressure of the outlet (32) reaches within the target pressure ratio range, and the first solenoid valve (41) is controlled to close.

7. The gas flow control method of claim 1, wherein The pressure of the front chamber (12) is obtained through a first pressure sensor, and the pressure of the outlet (32) is obtained through a second pressure sensor or obtained by subtracting pressure loss from the pressure of the intake pipe of the engine.

8. The gas flow control method of claim 1, wherein The pressure of the outlet (32) is adjusted by adjusting the gas flow rate of the outlet (32), and the gas flow rate of the outlet (32) is adjusted by adjusting the throat cross-sectional area of ​​the Laval tube (3).

9. An engine system characterized by, The invention comprises an intake pipe and a flow valve of an engine, wherein the flow valve controls the intake flow of the engine by adopting the gas flow control method according to any one of claims 1 to 8.

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