Gas flow control method and engine system

Abstract

The invention discloses a gas flow control method and an engine system, and relates to the technical field of engine gas inlet flow control. According to the gas flow control method, the pressure of a front cavity and the pressure of an outlet of a Laval pipe are obtained, the ratio of the pressure of the front cavity to the pressure of the outlet is calculated, whether the ratio of the pressure of the front cavity to the pressure of the outlet is within a target pressure ratio range or not is judged, and if yes, the gas flow is controlled. If so, the outlet is decoupled from a pressure regulating mechanism for regulating the pressure of the front chamber by means of a pressure decoupling module. If not, the outlet is coupled with a pressure adjusting mechanism through a pressure decoupling module, and the flowing direction of the gas is controlled, so that the ratio of the pressure of the front cavity to the pressure of the outlet reaches the target pressure ratio range, and then the gas in the Laval pipe reaches the supersonic speed state; and the pressure of the front chamber is stable or adjusted along with the pressure fluctuation of the air inlet pipe of the engine, so that the gas flow control precision is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of engine gas flow control, and in particular to a gas flow control method and an engine system. Background Art

[0002] As the requirements for engine emissions become increasingly stringent, there is an urgent need to accurately control the engine's intake process. The flow valve is connected to the engine's intake pipe to achieve controllable, precise and stable engine intake control.

[0003] At present, the flow valve is usually equipped with a two-stage regulating mechanism. The first-stage regulating mechanism is used to adjust the pressure in the valve cavity, and the second-stage regulating mechanism controls the displacement of the valve core, thereby controlling the throat cross-sectional area of ​​the venturi tube to achieve the purpose of changing the gas flow area. By adjusting the pressure in the cavity, the gas passing through the venturi tube reaches a supersonic state, and by controlling the throat cross-sectional area of ​​the venturi tube, the gas flow is controlled. However, the use of a first-stage motor actuator in the first-stage regulating mechanism will increase product costs, and will interfere with the magnetic field of the feedback system of the second-stage motor actuator, affecting the control accuracy of the second-stage motor actuator. In order to solve the above problems in the prior art, a pressure regulating mechanism driven by a mechanical mechanism is provided to keep the pressure parameters in the cavity stable, and the gas pressure at the outlet of the venturi tube is directly fed back to act on the pressure regulating mechanism. However, the gas pressure at the outlet of the venturi tube will fluctuate under steady-state conditions due to conventional pressure fluctuations (there is no pressure fluctuation in the engine intake pipe), and will then be fed back to the regulation control of the pressure regulating mechanism, causing gas disturbance in the cavity. The disturbed gas will cause pressure fluctuations, and the cross-sectional area at the throat of the venturi tube needs to be controlled by the valve stem position of the electromagnetic actuator to compensate for the flow, which will affect the flow control accuracy of the system and also put forward higher requirements for control. Summary of the invention

[0004] The object of the present invention is to provide a gas flow control method and an engine system to achieve stability of the inlet pressure of the Laval tube under steady-state conditions and to adjust the pressure along with the outlet pressure of the Laval tube under transient conditions, so as to achieve higher gas flow control accuracy.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A gas flow control method is used to control the intake flow of an engine, wherein the intake pipe of the engine is connected to 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 regulating 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 regulating mechanism, and the gas flow control method comprises the following steps:

[0007] Obtaining 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] determining whether a ratio of the pressure of the front chamber to the pressure of the outlet is within a target pressure ratio range;

[0009] If so, the outlet is decoupled from the pressure regulating mechanism through the pressure decoupling module; if not, the outlet is coupled to 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 within the target pressure ratio range.

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

[0011] By controlling both the first solenoid valve and the second solenoid valve to be closed, the outlet can be decoupled from the pressure regulating mechanism; by controlling one of the first solenoid valve and the second solenoid valve to be opened, the outlet can be coupled to the pressure regulating mechanism.

[0012] As an optional scheme for the gas flow control method, the target pressure ratio range is between a set pressure upper limit and a set pressure lower limit, and the gas flow direction 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 or the set pressure lower limit.

[0013] As an optional scheme for 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 maximum limit, the outlet is coupled to 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 includes a pressure regulator valve chamber and a pressure regulator spring chamber separated by a diaphragm, and a pressure regulator valve for controlling the opening of the air inlet is arranged in the pressure regulator valve chamber;

[0015] When the ratio of the pressure in the front chamber to the pressure at the outlet is greater than the set pressure maximum limit, the second solenoid valve is controlled to open, the pressure regulator spring chamber is connected to the outlet through the second gas feedback passage, and under the action of the gas pressure at the outlet, the gas in the pressure regulator spring chamber flows to the outlet through the second one-way valve, the pressure in the pressure regulator spring chamber decreases, the diaphragm drives the pressure regulator valve to move toward the pressure regulator spring chamber, the opening of the air inlet decreases, and then the pressure in the front chamber decreases, until the ratio of the pressure in the front chamber to the pressure at the outlet reaches within the target pressure ratio range, and the second solenoid valve is controlled to close.

[0016] As an optional scheme for 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 set pressure minimum limit, the outlet is coupled to the front chamber through the pressure decoupling module, and the gas is controlled to flow from the outlet to the pressure regulating mechanism.

[0017] As an optional scheme for 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 set pressure minimum limit, the first solenoid valve is controlled to open, and the gas at the outlet flows to the pressure regulator spring chamber through the first one-way valve, and compresses the pressure regulator valve chamber through 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 within the target pressure ratio range, and the first solenoid valve is controlled to close.

[0018] As an optional scheme 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 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 comprises an intake pipe and a flow valve of the engine, wherein the flow valve controls the intake flow of the engine by using a gas flow control method as described in any of the above schemes.

[0021] Beneficial effects of the present invention:

[0022] The gas flow control method provided by the present invention obtains the pressure of the front chamber of the Laval tube and the pressure of the outlet, calculates the ratio of the pressure of the front chamber to the pressure of the outlet, and determines whether the ratio of the pressure of the front chamber to the pressure of the outlet is within the target pressure ratio range. If so, it means that the pressure of the front chamber at this time can make the gas in the Laval tube reach a supersonic state, and the pressure of the front chamber needs to be kept stable. In order to avoid the pressure of the front chamber being affected by the conventional pressure fluctuations of the outlet, the outlet is decoupled from the pressure regulating mechanism used to regulate the pressure of the front chamber through a 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 change of the outlet pressure so that the gas in the Laval tube reaches a supersonic state. The outlet is coupled to the pressure regulating mechanism through a 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 within the target pressure ratio range, thereby making the gas in the Laval tube reach a supersonic state. The gas flow control method provided by the present invention can decouple or couple the outlet and the pressure regulating mechanism through a 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, thereby ensuring that the pressure of the front chamber is stable or adjusted according to the pressure fluctuation of the engine intake pipe, so that the gas flow control accuracy is higher.

[0023] The engine system provided by the present invention connects the engine intake 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, thereby realizing accurate and stable control of the engine intake. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a flow valve provided in an embodiment of the present invention;

[0025] Figure 2 is a cross-section of the flow valve provided in the embodiment of the present invention Figure 1 ;

[0026] Figure 3 is an exploded view of a flow valve provided in an embodiment of the present invention;

[0027] Figure 4 is a cross-sectional view of a flow valve provided by an embodiment of the present invention Figure 1 ;

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

[0029] Figure 6 It is a structural schematic diagram of an outlet provided by an embodiment of the present invention being connected to a pressure regulating mechanism through a pressure decoupling module;

[0030] Figure 7 is a cross-sectional view of a flow valve provided by an embodiment of the present invention Figure 2 ;

[0031] Figure 8 is a cross-section of the flow valve provided in the embodiment of the present invention Figure 2 ;

[0032] Fig. 9 is a schematic diagram of the structure of the Laval tube and the valve stem provided by an embodiment of the present invention;

[0033] Fig.10 is a schematic diagram of the working principle of the pressure decoupling module provided by an embodiment of the present invention;

[0034] Fig.11 It is a flow chart of a gas flow control method provided by an embodiment of the present invention.

[0035] In the figure:

[0036] 1. Valve body; 11. Air 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 solenoid valve; 42. First one-way valve; 43. Second solenoid valve; 44. Second one-way valve;

[0040] 5. Electromagnetic actuator;

[0041] 6. Valve stem;

[0042] 7. Controller. DETAILED DESCRIPTION

[0043] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only 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 "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0048] like Figure 1-Figure 10As shown, this embodiment provides an engine system, which includes an intake pipe and a flow valve of the engine, and the flow valve is connected to the intake pipe of the engine to control the intake flow of the engine. The flow valve includes a valve body 1, a Laval tube 3 and a pressure decoupling module 4, and the valve body 1 is provided with an intake port 11 and a front chamber 12, and the intake port 11 is connected to the front chamber 12 through a pressure regulating mechanism 2, and the pressure regulating mechanism 2 is used to regulate the pressure of the front chamber 12, and the front chamber 12 is provided with a first pressure sensor, and the first pressure sensor is used to detect the pressure of the front chamber 12. The Laval tube 3 includes an inlet 31 and an outlet 32, and the inlet 31 is connected to the front chamber 12, and the outlet 32 ​​is provided with a second pressure sensor, and the second pressure sensor is used to detect the pressure of the outlet 32, and the engine intake pipe is connected to the outlet 32 ​​to achieve accurate control of the intake flow of the engine. In other embodiments, since the intake pipe of the engine is provided with a pressure sensor, the outlet 32 ​​may not be provided with a pressure sensor, and the pressure of the outlet 32 ​​can be obtained by subtracting the pressure loss from the pressure of the intake pipe of the engine, and the pressure loss is obtained according to experience or experiment.

[0049] Specifically, the pressure regulating mechanism 2 includes a pressure regulating valve 21, a diaphragm 22 and a spring 23. A pressure regulating chamber is provided in the valve body 1. The two sides of the diaphragm 22 are connected to the pressure regulating valve 21 and the spring 23 respectively, and the pressure regulating chamber is divided into a pressure regulating valve chamber and a pressure regulating spring chamber. The pressure regulating valve chamber is connected to the air inlet 11 and the front chamber 12 through the pressure regulating valve 21. The change of gas pressure in the pressure regulating spring chamber can drive the pressure regulating valve 21 to move through the diaphragm 22, and adjust the opening of the air inlet 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 air inlet 11 of the valve body 1. The pressure regulating mechanism 2 is provided in the pressure regulating chamber. The pressure parameters entering the front chamber 12 are kept stable through the pressure regulating mechanism 2.

[0050] The flow valve also includes an electromagnetic actuator 5 and a valve stem 6. The valve stem 6 passes through the front chamber 12 and is connected to the Laval tube 3. The electromagnetic actuator 5 drives the valve stem 6 to move and adjust the throat cross-sectional area of ​​the Laval tube 3 to control the gas flow at the outlet 32.

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

[0052] Through the combined action of the pressure regulating mechanism 2 and the electromagnetic actuator 5, the pressure ratio between the inlet 31 and the outlet 32 ​​of the Laval tube 3 is maintained under the condition that the gas in the Laval tube 3 can reach a supersonic state. In this embodiment, only one motor is needed, and the pressure regulating mechanism 2 adopts a mechanical pressure regulating mechanism, eliminating a primary motor or electromagnetic actuator. The mechanical pressure regulating structure has a simple structure, and can more easily realize the precise control of the gas flow rate by the continuous flow valve, while reducing the cost of the product.

[0053] However, since the pressure of the outlet 32 ​​is affected by the pressure fluctuation of the engine intake pipe, the outlet 32 ​​is usually connected to the spring chamber of the pressure regulator through a gas feedback passage, so that the pressure of the gas at the outlet 32 ​​is used as the actuating factor of the pressure regulator valve 21, and the pressure of the front chamber 12 is adjusted together with the pressure regulating mechanism 2. The pressure of the front chamber 12 and the outlet 32 ​​form a linear relationship, which can achieve the effect of maintaining the pressure difference between the inlet 31 and the outlet 32 ​​of the Laval tube 3 constant. The gas pressure of the front chamber 12 is adjusted with the fluctuation of the pressure of the outlet 32. Therefore, when the pressure of the outlet 32 ​​decreases, the gas pressure of the front chamber 12 also decreases accordingly, which can ensure that the pressure ratio of the inlet 31 and the outlet 32 ​​of the Laval tube 3 is maintained under the condition that the gas in the Laval tube 3 is in a supersonic state. When the pressure of the outlet 32 ​​increases, the gas pressure of the inlet 31 of the Laval tube 3 also increases accordingly, so that the pressure ratio of the inlet 31 and the outlet 32 ​​of the Laval tube 3 is maintained under the condition that the gas in the Laval tube 3 is in a supersonic state.

[0054] However, under steady-state conditions, the normal pressure fluctuation of the outlet 32 ​​(the engine intake pipe does not experience pressure fluctuation) will also be fed back to the regulation and control of the pressure regulating mechanism 2, resulting in gas disturbance in the front chamber 12, and the disturbed gas will cause pressure fluctuation in the front chamber 12. In the prior art, the electromagnetic actuator 5 drives the valve stem 6 to move, and the throat cross-sectional area of ​​the Laval tube 3 is controlled to compensate for the gas flow, but this will affect the flow control accuracy.

[0055] In this embodiment, a pressure decoupling module 4 is provided between the outlet 32 ​​and the pressure regulating mechanism 2. The pressure decoupling module 4 can selectively decouple or couple the outlet 32 ​​from the pressure regulating mechanism 2, and when the outlet 32 ​​is coupled with the pressure regulating mechanism 2, the flow direction of the gas can be controlled. By providing the pressure decoupling module 4, the outlet 32 ​​can be selectively decoupled or coupled with the pressure regulating mechanism 2 according to different working conditions, and when the outlet 32 ​​is coupled with the pressure regulating mechanism 2, the flow direction of the gas can be controlled, 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, thereby improving the control accuracy of the gas flow rate.

[0056] Specifically, a first gas feedback passage 13 and a 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 solenoid valve 41, a first one-way valve 42, a second solenoid valve 43 and a second one-way valve 44. The first solenoid valve 41 and the first one-way valve 42 are arranged in the first gas feedback passage 13, and the first one-way valve 42 is used for one-way conduction from the outlet 32 ​​to the pressure regulator spring chamber. The second solenoid 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 from the pressure regulator spring chamber to the outlet 32.

[0057] like Figure 6As shown, a gas feedback inlet 15 and a gas feedback outlet 16 are also provided on the valve body 1. The gas feedback inlet 15 is located in the cavity where the outlet 32 ​​is located, and the gas feedback outlet 16 is located in the voltage regulator spring cavity. One end of the first gas feedback passage 13 and one end of the second gas feedback passage 14 are both connected to the gas feedback inlet 15, and the other end of the first gas feedback passage 13 and the other end of the second gas feedback passage 14 are both connected to 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 voltage regulator spring cavity through the gas feedback outlet 16, so that the gas peak value of the outlet 32 ​​refreshes the highest value of the front chamber 12, or the gas valley value of the outlet 32 ​​refreshes the lowest value of the front chamber 12.

[0058] The engine system also includes a controller 7, a first pressure sensor and a second pressure sensor are both connected to the controller 7 by signal, a first solenoid valve 41 and a second solenoid valve 43 are both electrically connected to 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 ​​based on 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, the controller 7 performs closed-loop regulation with the target pressure ratio range as the target, and maintains the high response and fast feedback function of the pressure of the front chamber 12 to the pressure of the outlet 32 ​​under the necessary working conditions, so that the flow valve can be accurately controlled under 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 within the target pressure ratio range, the controller 7 controls the first solenoid valve 41 and the second solenoid 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 within the target pressure ratio range, it means that the gas in the Laval tube 3 has not formed a supersonic flow, and the pressure of the outlet 32 ​​needs to be used as the actuating factor of the pressure regulator valve 21, and the pressure of the front chamber 12 is adjusted 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 within the target pressure ratio range.

[0060] The target pressure ratio range is between the set pressure upper limit and the set pressure lower limit. 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, it means that the pressure of the front chamber 12 is relatively small and the pressure of the front chamber 12 needs to be increased. At this time, the controller 7 controls the first solenoid valve 41 to open so that the gas at the outlet 32 ​​can enter the spring chamber of the pressure regulator through the first one-way valve 42. The gas pressure peak at the outlet 32 ​​continuously refreshes the maximum value of the pressure of the front chamber 12, and the pressure of the front chamber 12 continues to rise until the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 ​​reaches the target pressure ratio range. The first solenoid valve 41 is closed so that the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 ​​reaches within 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 maximum limit, it means that the pressure of the front chamber 12 is relatively large and the pressure of the front chamber 12 needs to be reduced. At this time, the controller 7 controls the second solenoid valve 43 to open, so that the spring chamber of the pressure regulator is connected with the outlet 32 ​​through the second gas feedback passage 14. Under the action of the gas pressure at the outlet 32, the trough of the gas pressure at the outlet 32 ​​continuously refreshes the minimum value of the pressure of the front chamber 12, so that the pressure of the front chamber 12 is reduced 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. The second solenoid 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 within the target pressure ratio range.

[0062] That is, the pressure decoupling module 4 provided in this embodiment, under steady-state conditions, 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 solenoid valve 41 and the second solenoid valve 43 are both closed, the gas feedback path is disconnected, and the flow valve operates without feedback. Under transient conditions, the ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 ​​is controlled through the gas feedback path, and closed-loop control is performed with the target pressure ratio range as the target, and the adjustment direction is clearly defined to achieve a controllable ratio of the pressure of the front chamber 12 to the pressure of the outlet 32. The ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 ​​is accurately controlled, which is conducive to more accurate flow control of the flow valve.

[0063] Furthermore, the first solenoid valve 41 and the second solenoid valve 43 are both solenoid switch valves or solenoid proportional valves. The solenoid switch valve can control the on-off of the first gas feedback passage 13 and the second gas feedback passage 14, and the solenoid 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 rate of the gas, thereby further achieving precise control.

[0064] The solenoid valve and the one-way valve in the pressure decoupling module 4 are low in cost and reduce or avoid the electromagnetic interference generated by setting a two-stage electromagnetic mechanism in the prior art. In addition, the pressure of the gas feedback path in this embodiment is much lower than the pressure of the air inlet 11, and the energy consumption is lower.

[0065] In the flow valve provided in this embodiment, a mechanical structure is used in the pressure regulating mechanism 2 for pressure feedback control, and a one-way valve is used to guide the direction of the gas. A simple solenoid valve drive control can be used for pressure regulation control, which can greatly simplify the software and hardware design of the control logic and the drive circuit, thereby reducing the failure items of the flow valve and improving the reliability and robustness of the flow valve.

[0066] like Fig.11 As shown, this embodiment also provides a gas flow control method, which is applied to the above-mentioned flow valve and includes the following steps:

[0067] S10 , 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 ​​.

[0068] The pressure of the front chamber 12 is obtained through the first pressure sensor, and the pressure of the outlet 32 ​​is obtained through the second pressure sensor or obtained by subtracting the pressure loss from the pressure of the intake pipe of the engine. 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 ​​based on the received pressure of the front chamber 12 and the pressure of the outlet 32.

[0069] The pressure of the front chamber 12 is adjusted by the pressure regulating mechanism 2, 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 is adjusted by adjusting the throat cross-sectional area of ​​the Laval tube 3. Specifically, the electromagnetic actuator 5 drives the valve stem 6 to move, adjusts the throat cross-sectional area of ​​the Laval tube 3, and controls the gas flow rate of the outlet 32.

[0070] S20, determining 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 so, executing S31; if not, executing S32.

[0071] S31 . Decouple the outlet 32 ​​from the pressure regulating mechanism 2 via the pressure decoupling module 4 .

[0072] Since the position of the valve stem 6 remains unchanged, that is, when the throat cross-sectional area of ​​the Laval tube 3 remains unchanged, the pressure of the outlet 32 ​​is affected by the pressure fluctuation of the engine intake pipe. In order to make 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 and a spring 23 connected by a diaphragm 22. The cavity where the spring 23 is located is the pressure regulator spring cavity. The outlet 32 ​​is connected to the pressure regulator spring cavity 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 air inlet 11 is connected to the front chamber 12 through the pressure regulator valve cavity, the pressure regulator valve 21 abuts against the air inlet 11, and the pressure change in the pressure regulator spring cavity affects the opening of the air inlet 11, thereby affecting the gas flow rate entering the front chamber 12 through the air inlet 11 via the pressure regulator valve cavity. When the volume and temperature of the front chamber 12 remain unchanged, the greater the gas flow rate entering the front chamber 12, the greater the pressure in the front chamber 12, that is, the greater the pressure at the inlet 31.

[0073] Specifically, the pressure decoupling module 4 includes a first solenoid valve 41, a first one-way valve 42, a second solenoid valve 43, and a second one-way 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 solenoid valve 41 and the first one-way valve 42 are arranged in the first gas feedback passage 13, and the second solenoid valve 43 and the second one-way valve 44 are arranged in the second gas feedback passage 14. Controlling the first solenoid valve 41 and the second solenoid 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 current chamber 12 to the pressure of the outlet 32 ​​is within the target pressure ratio range, the first solenoid valve 41 and the second solenoid valve 43 are controlled to be closed, that is, the first gas feedback passage 13 and the second gas feedback passage 14 are disconnected 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 under steady-state conditions, in order to prevent the normal pressure fluctuation of the outlet 32 ​​from 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 spring chamber of the pressure regulator through the pressure decoupling module 4, and the controller 7 controls the first solenoid valve 41 and the second solenoid valve 43 to be closed, so that the outlet 32 ​​is decoupled from the spring chamber of the pressure regulator, thereby ensuring that the gas pressure of the front chamber 12 is stable under steady-state conditions.

[0076] S32, coupling the outlet 32 ​​to the pressure regulating mechanism 2 through the pressure decoupling module 4, 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 ​​reaches within the target pressure ratio range.

[0077] Controlling one of the first solenoid valve 41 and the second solenoid valve 43 to open can couple the outlet 32 ​​with the pressure regulating mechanism 2. The target pressure ratio range is between the set pressure upper limit and the set pressure lower limit, 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 or the set pressure lower limit.

[0078] Specifically, 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, the outlet 32 ​​is coupled to the pressure regulating mechanism 2 through the pressure decoupling module 4, and the gas is controlled to flow from the pressure regulating mechanism 2 to the outlet 32. Further, 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, 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 the target pressure ratio range, and the second solenoid valve 43 is controlled to close.

[0079] 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. Further, 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 at the outlet 32 ​​flows to the pressure regulator spring chamber through the first one-way valve 42, and compresses the pressure regulator valve chamber through the diaphragm 22. The diaphragm 22 drives the pressure regulator valve 21 to move away from the pressure regulator spring chamber, and 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 the target pressure ratio range, and the first solenoid valve 41 is controlled to close.

[0080] The gas flow control method provided in this 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, thereby ensuring that the pressure of the front chamber 12 is stable or adjusted as the pressure of the engine intake pipe changes, thereby making the gas flow control more accurate.

[0081] This embodiment provides an engine system, which uses the above-mentioned gas flow control method to control the intake flow of the engine, and the engine intake pipe is connected to the outlet 32. The flow valve can selectively decouple or couple the outlet 32 ​​with 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 ratio of the pressure of the front chamber 12 to the pressure of the outlet 32 ​​is within the target pressure ratio range, thereby improving the control accuracy of the gas flow.

[0082] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there will be changes in the specific implementation methods and application scopes. The content of this specification should not be understood as limiting the present invention.

Claims

1. A gas flow control method for controlling the intake flow of an engine, wherein the intake pipe of the engine is connected to a flow valve, and is characterized in that: The flow valve comprises a valve body (1), a Laval tube (3) and a pressure decoupling module (4); the air inlet (11) of the valve body (1) is connected to a front chamber (12) via a pressure regulating mechanism (2); the inlet (31) of the Laval tube (3) is connected to the front chamber (12); the outlet (32) of the Laval tube (3) is connected to an air intake pipe of the engine; the pressure decoupling module (4) is arranged between the outlet (32) and the pressure regulating mechanism (2); 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 a ratio of a pressure of the front chamber (12) to a pressure of the outlet (32) is within a target pressure ratio range; If so, the outlet (32) is decoupled from the pressure regulating mechanism (2) through the pressure decoupling module (4); if not, the outlet (32) is coupled to 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 within the target pressure ratio range.

2. The gas flow control method according to claim 1, characterized in that: The pressure decoupling module (4) comprises a first solenoid valve (41), a first one-way valve (42), a second solenoid valve (43) and a second one-way 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 solenoid valve (41) and the first one-way valve (42) are arranged in the first gas feedback passage (13); and the second solenoid valve (43) and the second one-way valve (44) are arranged in the second gas feedback passage (14); By controlling both the first solenoid valve (41) and the second solenoid valve (43) to be closed, the outlet (32) can be decoupled from the pressure regulating mechanism (2); and by controlling one of the first solenoid valve (41) and the second solenoid valve (43) to be opened, the outlet (32) can be coupled to the pressure regulating mechanism (2).

3. The gas flow control method according to claim 2, characterized in that: The target pressure ratio range is between a set pressure upper limit and a set pressure lower limit, 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 or the set pressure lower limit.

4. The gas flow control method according to claim 3, characterized in that: If 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 outlet (32) is coupled to the pressure regulating mechanism (2) through the pressure decoupling module (4), and the gas is controlled to flow from the pressure regulating mechanism (2) to the outlet (32).

5. The gas flow control method according to claim 4, characterized in that: The pressure regulating mechanism (2) comprises a pressure regulator valve chamber and a pressure regulator spring chamber separated by a diaphragm (22), wherein a pressure regulator valve (21) for controlling the opening of the air inlet (11) is arranged in the pressure regulator valve chamber; When the ratio of the pressure in the front chamber (12) to the pressure at the outlet (32) is greater than the set pressure upper 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 at 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 toward the pressure regulator spring chamber, the opening of the air inlet (11) decreases, and the pressure in the front chamber (12) decreases, until the ratio of the pressure in the front chamber (12) to the pressure at the outlet (32) reaches within the target pressure ratio range, and the second solenoid valve (43) is controlled to close.

6. The gas flow control method according to claim 5, characterized in that: 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).

7. The gas flow control method according to claim 6, characterized in that: 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 at 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.

8. The gas flow control method according to claim 1, characterized in that: 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 through the pressure of the intake pipe of the engine minus the pressure loss.

9. The gas flow control method according to claim 1, characterized in that: 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).

10. An engine system, characterized in that It comprises an intake pipe and a flow valve of an engine, wherein the flow valve adopts the gas flow control method as described in any one of claims 1 to 9 to control the intake flow of the engine.

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