Control device for cold bypass and EGR cooler bypass in engine

Abstract

The invention provides a control device for an intercooling bypass and an EGR cooler bypass in an engine, and belongs to the technical field of engines, the control device comprises a multi-way butterfly valve provided with at least three airflow channels, and the input end of the multi-way butterfly valve is communicated with a supercharger; the EGR cooler is arranged on the EGR cooling branch, one end of the EGR cooling branch communicates with the EGR loop, and the other end of the EGR cooling branch communicates with the intake manifold; one end of the EGR bypass branch communicates with the EGR loop through a first airflow channel of the multi-way butterfly valve, and the other end of the EGR bypass branch communicates with the EGR cooling branch and is located between the EGR cooler and the intake manifold; one end of the inter-cooling bypass branch is communicated with the intake manifold, and the other end of the inter-cooling bypass branch is communicated with a second airflow channel of the multi-way butterfly valve; and one end of the intercooler communicates with the intake manifold, and the other end of the intercooler communicates with the third airflow channel of the multi-way butterfly valve. By additionally arranging the multi-way butterfly valve, the purpose of adjusting the cooling strategies of the EGR system and the intercooling system at the same time is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of engines, and in particular to a control device for engine intercooler bypass and EGR cooler bypass. Background Art

[0002] The main function of the EGR (Exhaust Gas Re-circulation) system cooler is to reduce the temperature of the exhaust gas that flows back from the exhaust system to the intake system. This is because during the operation of the engine, part of the burned exhaust gas will be reintroduced into the intake system, mixed with fresh air and then re-entered into the cylinder for combustion. However, these exhaust gases usually have a high temperature. If they are not cooled, they may cause excessive heat load on the engine's intake system, cylinder wall, piston and other components, affecting the performance and life of the engine.

[0003] When the engine uses turbocharging or supercharging technology, the supercharger will significantly increase the intake pressure, but it will also increase the intake temperature. High-temperature air will reduce the density of the air, which will affect the engine's charging efficiency. The intercooler cools the pressurized air and reduces its temperature, thereby increasing the intake density and allowing the engine to inhale more and denser air.

[0004] However, during engine operation, due to the complexity of the operating conditions, it is sometimes necessary to adjust the cooling effect of the intake system to adapt to different needs. For example, when the engine is running in a low-load state in a cold environment, especially in the initial stage after a cold start, due to the low EGR rate and relatively low exhaust temperature under natural conditions, if the same cooling strategy as the high-load condition is adopted at this time, that is, all exhaust gas in the EGR branch is allowed to flow through the EGR cooler for cooling, it may cause the exhaust gas to have an abnormally low temperature when it flows out of the EGR module. Similarly, due to the low external ambient temperature, if the pressurized air is still cooled by the intercooler at this time, the intake temperature may be too low, which will have an adverse effect on the engine performance. Too low intake temperature will increase the compression ratio of the engine, which may cause engine knock or ignition difficulties.

[0005] In this case, the low-temperature gas may encounter water vapor in the cold air in the intake system and then condense into ice, increasing the risk of icing and blockage at the intake. In addition, long-term low-temperature operation may also accelerate the material aging process of the EGR system and its related components. For example, the metal parts of the cooler may be damaged due to temperature fluctuations, and the seals may harden and lose elasticity due to low temperatures, thereby affecting the sealing and durability of the EGR system. Under extreme low temperature conditions, the cooling medium inside the intercooler may freeze or freeze, causing damage to the intercooler. By bypassing the intercooler, the cooling medium can be prevented from staying inside the intercooler for a long time, thereby reducing the risk of icing or freezing and protecting the safety of the intercooler.

[0006] In addition, under low temperature and low load conditions, the thermal efficiency of the engine may be affected. Appropriate intake temperature can enable the engine to reach normal operating temperature faster, thereby improving thermal efficiency, and also helping to improve the atomization effect of the fuel, promote the full combustion of the fuel, and further improve the performance of the engine.

[0007] In summary, inappropriate EGR cooling and intercooling strategies in low-temperature environments may cause a series of problems, including intake air icing, increased risk of blockage, and accelerated material aging, all of which may ultimately have an adverse effect on vehicle dynamics. Therefore, in cold-region environments with low loads, it is necessary to adjust the cooling strategies of the EGR system and intercooling system at the same time, such as reducing the amount of exhaust gas flowing through the EGR cooler or reducing the cooling efficiency of the cooler to ensure that the exhaust gas maintains an appropriate temperature when it flows out of the EGR module. Summary of the invention

[0008] In view of this, it is necessary to provide a control device for engine intercooler bypass and EGR cooler bypass to achieve the purpose of simultaneously adjusting the cooling strategies of the EGR system and the intercooler system.

[0009] In order to solve the above problems, the present invention provides a control device for engine intercooler bypass and EGR cooler bypass, comprising: A multi-way butterfly valve is provided with at least three air flow channels, and the input end is connected to the supercharger; An EGR cooler is arranged on an EGR cooling branch, one end of the EGR cooling branch is connected to the EGR circuit, and the other end of the EGR cooling branch is connected to the intake manifold; An EGR bypass branch, one end of which is connected to the EGR circuit through the first air flow channel of the multi-way butterfly valve, and the other end of which is connected to the EGR cooling branch and is located between the EGR cooler and the intake manifold; An intercooler bypass branch, one end of which is connected to the intake manifold, and the other end of which is connected to the second air flow channel of the multi-way butterfly valve; The intercooler has one end connected to the intake manifold and the other end connected to the third air flow channel of the multi-way butterfly valve.

[0010] In a possible implementation, the EGR cooling branch is also connected to the fourth channel of the multi-way butterfly valve.

[0011] In a possible implementation, the control device for engine intercooler bypass and EGR cooler bypass further includes: An EGR valve is arranged on the EGR cooling branch and is located between the EGR cooler and the intake manifold; The throttle valve is arranged at the entrance of the intake manifold.

[0012] In a possible implementation, the control device for engine intercooler bypass and EGR cooler bypass further includes: The engine control unit is used to adjust the opening of the EGR valve based on the engine speed, load and temperature to control the recirculation amount of the exhaust gas.

[0013] In a possible implementation, the engine control unit is further used to control at least one of the first air flow channel and the second air flow channel of the multi-way butterfly valve to open when the ambient temperature of the engine is less than or equal to a preset temperature threshold.

[0014] In one possible implementation, the engine control unit is also used to determine the target intake temperature based on the engine operating conditions and the ambient temperature of the engine, and based on the target intake temperature and the target intercooler after-temperature, determine whether the EGR valve is closed. When the EGR valve is closed, the opening of the multi-way butterfly valve is adjusted to achieve the target intercooler after-temperature. When the EGR valve is open, the opening of the multi-way butterfly valve is adjusted to achieve the target intake temperature.

[0015] In a possible implementation, when the EGR valve is closed, adjusting the opening of the multi-way butterfly valve to achieve the target intercooler after-temperature includes: When the EGR valve is closed, the throttle opening is determined based on the target intake volume to adjust the throttle, and the target intercooler after temperature is determined based on the target intake temperature. The target intercooler after temperature is used as the control target, and the opening of the multi-way butterfly valve is adjusted to achieve the target intercooler after temperature.

[0016] In a possible implementation, when the EGR valve is opened, adjusting the opening of the multi-way butterfly valve to achieve the target intake air temperature includes: When the EGR valve is opened, the throttle opening and the EGR valve opening are determined based on the target intake volume to adjust the throttle and the EGR valve, and the opening of the multi-way butterfly valve is adjusted based on the preset openings of the first air flow channel and the second air flow channel, and the target intercooler after-temperature to achieve the target intake temperature.

[0017] In a possible implementation, the engine control unit is further configured to: When the ambient temperature of the engine is less than or equal to a preset temperature threshold, based on the current operating condition of the engine and the ambient temperature, a target intake air volume, a target intake air temperature and an opening of the second air flow channel of the multi-way butterfly valve are determined, and a throttle opening and an EGR valve opening are determined based on the target intake air volume; Determine the target mixture temperature after the EGR cooler based on the target intake air temperature and the real-time monitored intercooler post-temperature and EGR valve opening; Adjust the opening of the multi-way butterfly valve to adjust the temperature after the EGR cooler to the target mixing temperature after the EGR cooler.

[0018] In a possible implementation, the engine control unit is further configured to: When the ambient temperature of the engine is less than a preset temperature threshold, the second air flow channel of the multi-way butterfly valve is controlled to open, and when the EGR valve is not opened, the throttle opening and the target intercooler after-temperature are determined based on the current operating conditions of the engine and the ambient temperature; Adjust the opening of the multi-way butterfly valve to achieve the target intercooler after-temperature.

[0019] The beneficial effects of adopting the above-mentioned implementation method are as follows: the control device for the engine intercooler bypass and the EGR cooler bypass provided by the present invention includes: a multi-way butterfly valve, which is provided with at least three air flow channels, and the input end is connected to the supercharger; an EGR cooler, which is arranged on the EGR cooling branch, one end of the EGR cooling branch is connected to the EGR circuit, and the other end is connected to the intake manifold; an EGR bypass branch, one end of which is connected to the EGR circuit through the first air flow channel of the multi-way butterfly valve, and the other end is connected to the EGR cooling branch and is located between the EGR cooler and the intake manifold; an intercooler bypass branch, one end of which is connected to the intake manifold, and the other end is connected to the second air flow channel of the multi-way butterfly valve; an intercooler, one end of which is connected to the intake manifold, and the other end is connected to the third air flow channel of the multi-way butterfly valve.

[0020] The present invention has a high degree of integration, and the design using a multi-way butterfly valve is often more compact, and can be more easily integrated with other system components (such as EGR cooler, EGR valve, intercooler, etc.), which can significantly reduce the length and complexity of the bypass line. This not only helps to save valuable engine compartment space, but also reduces the difficulty and cost of pipeline layout. This high degree of integration not only reduces system complexity, but also improves the reliability and maintainability of the overall system. By closely combining a multi-way butterfly valve such as a three-way butterfly valve or a four-way butterfly valve with the EGR cooler and intercooler circuit, a functionally complete and compact overall module can be formed. This modular design simplifies the installation process and improves the overall performance and reliability of the system. At the same time, it also facilitates subsequent maintenance and replacement work, because the entire module can be disassembled and assembled as a whole.

[0021] The multi-way butterfly valve can optimize the engine performance: while maintaining low emissions, by adjusting the exhaust gas recirculation amount, the combustion process of the engine is optimized, and the fuel economy and power performance are improved. During the low load or cold start stage of the engine, the exhaust gas temperature is low. If all the exhaust gas is cooled by the EGR cooler or intercooler, the gas temperature may be too low, and then ice or blockage may occur in the intake system. The multi-way butterfly valve reduces the proportion of low-temperature gas by increasing the flow of the bypass branch, avoids the cooling medium from staying in the heat exchanger for a long time, thereby reducing the risk of ice or freezing and protecting the safety of parts. In addition, by adjusting the temperature of the mixed gas, the multi-way butterfly valve also indirectly affects the temperature and heat capacity of the mixed gas entering the cylinder, thereby helping to optimize the combustion process and improve the fuel economy and emission performance of the engine. Therefore, the present invention achieves the purpose of adjusting the cooling strategy of the EGR system and the intercooler system at the same time by adding a multi-way butterfly valve, thereby reducing the amount of exhaust gas flowing through the EGR cooler or reducing the cooling efficiency of the cooler to ensure that the exhaust gas maintains an appropriate temperature when it flows out of the EGR module. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A schematic structural diagram of an embodiment of a control device for engine intercooler bypass and EGR cooler bypass provided by the present invention; Figure 2 A schematic structural diagram of another embodiment of the control device for engine intercooler bypass and EGR cooler bypass provided by the present invention; Figure 3 A flow chart of an embodiment of a method for controlling engine intercooler bypass and EGR cooler bypass provided by the present invention; Figure 4 The present invention is a flow chart of another embodiment of the method for controlling engine intercooler bypass and EGR cooler bypass provided by the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0026] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0027] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0028] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] like Figure 1 As shown, the present invention provides a control device for engine intercooler bypass and EGR cooler bypass, which includes: The multi-way butterfly valve is provided with at least three air flow channels, and the input end is connected to the supercharger; the multi-way butterfly valve can be a three-way butterfly valve; in another embodiment, Figure 2 As shown, the multi-way butterfly valve may be a four-way butterfly valve; An EGR (Exhaust Gas Re-circulation) cooler is arranged on an EGR cooling branch, one end of the EGR cooling branch is connected to the EGR circuit, and the other end is connected to the intake manifold; An EGR bypass branch, one end of which is connected to the EGR circuit through the first air flow channel of the multi-way butterfly valve, and the other end of which is connected to the EGR cooling branch and is located between the EGR cooler and the intake manifold; An intercooler bypass branch, one end of which is connected to the intake manifold, and the other end of which is connected to the second air flow channel of the multi-way butterfly valve; The intercooler has one end connected to the intake manifold and the other end connected to the third air flow channel of the multi-way butterfly valve.

[0030] It can be understood that the multi-way butterfly valve includes: a valve body, a transmission shaft, at least three valve plates, a motor, and a cooling water jacket arranged in the valve body; the valve body is provided with air flow channels corresponding to the number of valve plates and independent of each other, and each valve plate corresponds to an air flow channel; the at least three valve plates are connected to the motor through the transmission shaft.

[0031] The first valve plate and the second valve plate have the same phase angle, and are arranged 90° apart from the third valve plate; the design principle is: the two bypass branches have the same phase, the cooling branches passing through the intercooler or EGR cooler have the same phase, and the phase difference between the bypass and cooling branches is 90°.

[0032] The first valve plate is a valve plate corresponding to the first air flow channel, the second valve plate is a valve plate corresponding to the second air flow channel, and the third valve plate is a valve plate corresponding to the third air flow channel.

[0033] The control device for engine intercooler bypass and EGR cooler bypass provided by the present invention aims to optimize the intake temperature and intake efficiency under low temperature and low load conditions of the engine. This solution allows a part of the exhaust gas to be cooled through the EGR cooler before passing through the EGR valve, while the other part bypasses the EGR cooler through a bypass branch and is mixed through a three-way butterfly valve upstream / downstream of the EGR cooler to accurately control the temperature and flow of the exhaust gas entering the intake manifold. Similarly, this solution allows a part of the supercharged gas to be cooled through the intercooler before passing through the throttle, while the other part bypasses the intercooler through a bypass branch and is mixed through a three-way butterfly valve downstream of the intercooler to accurately control the temperature and flow of the supercharged gas entering the intake manifold. Through the combined action of the above two, the precise control of the overall intake temperature and flow of the engine is achieved together.

[0034] The working process of the control device for engine intercooler bypass and EGR cooler bypass is as follows: Exhaust gas diversion: The exhaust gas discharged from the engine is divided into two paths at a specific location, one path enters the EGR cooler, and the other path passes through the bypass branch.

[0035] Compressed gas diversion: The air pressurized by the supercharger is divided into two paths at a specific position, one path enters the intercooler, and the other passes through the bypass branch.

[0036] Exhaust gas cooling: The exhaust gas entering the EGR cooler exchanges heat with the coolant through the cooling pipe, and the temperature is significantly reduced.

[0037] Charged gas cooling: The charged gas entering the intercooler exchanges heat with the external environment through the cooling channel, and the temperature is significantly reduced.

[0038] Mixing of hot and cold exhaust gas: The cooled exhaust gas and the uncooled exhaust gas are mixed at the outlet of the three-way butterfly valve downstream of the EGR cooler. The opening of the butterfly valve is adjusted according to the engine operating conditions and emission requirements to optimize the mixing ratio.

[0039] Mixing of hot and cold boost gas: The cooled boost gas and the uncooled boost gas are mixed at the outlet of the three-way butterfly valve. The opening of the butterfly valve is adjusted according to the engine operating conditions and ambient temperature to optimize the mixing ratio.

[0040] Exhaust gas recirculation: The mixed exhaust gas enters the intake manifold through the EGR valve, mixes with fresh air and enters the combustion chamber again. The opening of the EGR valve is adjusted in real time by the engine control unit (ECU) according to parameters such as engine speed, load, temperature, etc. to control the amount of exhaust gas recirculation.

[0041] Engine intake: The boost mixture and exhaust gas mixture, after temperature adjustment by the three-way butterfly valve, enter the engine intake manifold after flow control by the throttle valve and EGR valve respectively, and finally enter the cylinder for combustion and work.

[0042] In some embodiments, the EGR cooling branch is also in communication with the fourth passage of the multi-way butterfly valve.

[0043] It can be understood that, in the present embodiment, the multi-way butterfly valve is a four-way butterfly valve, and the opening of the EGR cooling branch can be adjusted by the four-way butterfly valve.

[0044] In some embodiments, the control device for engine intercooler bypass and EGR cooler bypass further includes: An EGR valve is arranged on the EGR cooling branch and is located between the EGR cooler and the intake manifold; The throttle valve is arranged at the entrance of the intake manifold.

[0045] It can be understood that the EGR valve is located after the three-way butterfly valve and is used to control the amount of mixed exhaust gas entering the intake manifold.

[0046] The throttle valve is located after the three-way butterfly valve and is used to control the amount of mixed pressurized gas entering the intake manifold.

[0047] In some embodiments, the control device for engine intercooler bypass and EGR cooler bypass further includes: The engine control unit is used to adjust the opening of the EGR valve based on the engine speed, load and temperature to control the recirculation amount of the exhaust gas.

[0048] It can be understood that the mixed exhaust gas enters the intake manifold through the EGR valve, mixes with fresh air and enters the combustion chamber again. The opening of the EGR valve is adjusted in real time by the engine control unit according to parameters such as engine speed, load, temperature, etc. to control the amount of exhaust gas recirculation.

[0049] In some embodiments, the engine control unit is further used to control at least one of the first air flow channel and the second air flow channel of the multi-way butterfly valve to open when the ambient temperature of the engine is less than or equal to a preset temperature threshold.

[0050] It can be understood that the preset temperature threshold can be 0°C. When the EGR bypass and the intercooler bypass are controlled in linkage, when the ambient temperature of the engine is less than or equal to the preset temperature threshold, the engine control unit controls the first air flow channel and the second air flow channel of the multi-way butterfly valve to be closed.

[0051] When the EGR bypass and the intercooler bypass are independently controlled, when the ambient temperature of the engine is less than or equal to the preset temperature threshold, the engine control unit controls the first air flow channel of the multi-way butterfly valve to open and the second air flow channel to close.

[0052] In some embodiments, the engine control unit is also used to determine the target intake temperature based on the engine operating conditions and the ambient temperature of the engine, and based on the target intake temperature and the target intercooler after temperature, determine whether the EGR valve is closed. When the EGR valve is closed, the opening of the multi-way butterfly valve is adjusted to achieve the target intercooler after temperature. When the EGR valve is open, the opening of the multi-way butterfly valve is adjusted to achieve the target intake temperature.

[0053] In some embodiments, when the EGR valve is closed, adjusting the opening of the multi-way butterfly valve to achieve a target intercooler after-temperature includes: When the EGR valve is closed, the throttle opening is determined based on the target intake volume to adjust the throttle, and the target intercooler after temperature is determined based on the target intake temperature. The target intercooler after temperature is used as the control target, and the opening of the multi-way butterfly valve is adjusted to achieve the target intercooler after temperature.

[0054] In some embodiments, when the EGR valve is opened, adjusting the opening of the multi-way butterfly valve to achieve the target intake air temperature includes: When the EGR valve is opened, the throttle opening and the EGR valve opening are determined based on the target intake volume to adjust the throttle and the EGR valve, and the opening of the multi-way butterfly valve is adjusted based on the preset openings of the first air flow channel and the second air flow channel, and the target intercooler after-temperature to achieve the target intake temperature (intake temperature target value).

[0055] In some embodiments, the engine control unit is further configured to: When the ambient temperature of the engine is less than or equal to a preset temperature threshold, based on the current operating condition of the engine and the ambient temperature, a target intake air volume, a target intake air temperature and an opening of the second air flow channel of the multi-way butterfly valve are determined, and a throttle opening and an EGR valve opening are determined based on the target intake air volume; Determine the target mixture temperature after the EGR cooler based on the target intake air temperature and the real-time monitored intercooler post-temperature and EGR valve opening; Adjust the opening of the multi-way butterfly valve to adjust the temperature after the EGR cooler to the target mixing temperature after the EGR cooler.

[0056] In some embodiments, the engine control unit is further configured to: When the ambient temperature of the engine is less than a preset temperature threshold, the second air flow channel of the multi-way butterfly valve is controlled to open, and when the EGR valve is not opened, the throttle opening and the target intercooler after-temperature are determined based on the current operating conditions of the engine and the ambient temperature; Adjust the opening of the multi-way butterfly valve to achieve the target intercooler after-temperature.

[0057] In some embodiments, the control device for engine intercooler bypass and EGR cooler bypass specifically includes: EGR cooler: Responsible for cooling part of the exhaust gas discharged from the engine, reducing its temperature to reduce the generation of nitrogen oxides (NOx).

[0058] EGR bypass branch: provides a channel for uncooled exhaust gas to bypass the EGR cooler.

[0059] Intercooler: responsible for cooling the high-temperature and high-pressure gas from the supercharger, reducing its density and increasing the engine's air intake.

[0060] Intercooler bypass branch: provides a passage for uncooled boost gas to bypass the intercooler.

[0061] Multi-way butterfly valves such as three-way butterfly valves: Installed downstream / upstream of the EGR cooler and intercooler, divided into two air chambers on the left and right, one side is used to adjust the mixing ratio of cooled exhaust gas and uncooled exhaust gas, and the other side is used to adjust the mixing ratio of cooled boost gas and uncooled boost gas. The degree of opening of the butterfly valve determines the mixing ratio of hot and cold gases. The characteristics of the two-way butterfly valve include: the valve body is made of corrosion-resistant and high-temperature resistant materials to withstand the high temperature and high pressure environment of exhaust gas and boost gas. The butterfly plate is used as a control element to change the opening of the channel by rotation, thereby adjusting the flow of exhaust gas. The edge of the butterfly plate is usually specially treated to reduce fluid resistance and improve sealing performance. A sealing ring or sealing gasket is arranged between the butterfly plate and the valve seat to ensure that exhaust gas leakage can be effectively prevented in the closed state. The actuator of the butterfly valve (such as electric, pneumatic or hydraulic drive) receives a signal from the engine control unit (ECU) to accurately control the rotation angle of the butterfly plate to achieve precise regulation of the exhaust gas flow.

[0062] The three-way butterfly valve used in the present invention includes a valve body, a transmission shaft, three valve plates (a first valve plate, a second valve plate, and a third valve plate), a motor, and a cooling water jacket disposed in the valve body. Three independent air flow channels are disposed inside the valve body, each channel corresponds to a valve plate, and the valve plates are connected to the motor through a transmission shaft to achieve synchronous control. The first valve plate and the second valve plate have the same phase angle, and are arranged at a 90° phase angle difference with the third valve plate, ensuring that in the default state, the valve plate of the first channel is fully open, while the valve plates of the second channel and the third channel are fully closed.

[0063] Single drive shaft control: One drive shaft is used to control the opening and closing of three valve plates at the same time, and it is driven by a single motor, which simplifies the structure, reduces costs and improves reliability.

[0064] Cooling channel design: A cooling water jacket is provided inside the valve body. By circulating cooling water, the high-temperature gas flowing through the valve body can be cooled or the low-temperature gas can be kept warm, thus expanding the application range of the valve.

[0065] Flexible opening adjustment: Through precise control of the motor, all valves can be adjusted to any opening from fully closed to fully open, including half-open state, to meet the gas flow requirements under different working conditions.

[0066] Variable channel diameter: According to actual usage, channels with different diameters can be selected to optimize gas flow resistance and improve throttling efficiency.

[0067] EGR valve: located after the three-way butterfly valve, controls the amount of mixed exhaust gas entering the intake manifold.

[0068] Throttle: Located after the three-way butterfly valve, it controls the amount of mixed pressurized gas entering the intake manifold.

[0069] like Figure 3 As shown, the control method of engine intercooler bypass and EGR cooler bypass can be summarized into the following steps: ①Ambient temperature judgment: First, the system detects the current ambient temperature T amb If T amb ≤ 0°C, special condition processing is performed: the intercooler bypass is turned on to ensure that the cooling effect does not affect the engine operation due to the low ambient temperature; at the same time, the EGR system is turned on by default to optimize the combustion efficiency in low temperature environment.

[0070] ②Determine the target parameters: According to the current engine operating conditions (such as speed, load, etc.) and ambient temperature T amb , determine the target intake air volume and intake air temperature target value T1. At the same time, the intercooler bypass is adjusted to the preset opening K1 And EGR bypass is adjusted to the preset opening K2 , (K1 = K2 ).

[0071] ③EGR valve opening judgment: Detect whether the engine has an EGR valve opening requirement under the current working condition. If the EGR valve is closed, the intake air temperature target value T1 = Target intercooler after temperature T2 , enters the closed-loop control A with the intercooler after-temperature as the control target; if the EGR valve is open, the intake air temperature target value T1 =f(T2 , T3 , K1 , K2 ), enter into closed-loop control B with the intercooling after-temperature as the control target; ④ Intake air temperature model: Using one-dimensional simulation software and relevant test data, the mathematical relationship between the engine intake air temperature and the three-way butterfly valve opening (i.e., EGR cooler bypass / intercooler bypass degree) under different working conditions is constructed: T1=f(T2 , T3 , K1 , K2 ), and estimates the exact temperature of the engine intake air using only the existing sensor data and hardware status.

[0072] ⑤Intercooler bypass control (closed loop control A): Achieve target intercooler after-temperature T2 by opening the three-way butterfly valve , PID parameters: CURVE throttle valve temperature ⑥Intercooler bypass & EGR cooler bypass control (closed loop control B): Achieve target intake air temperature T1 by opening the three-way butterfly valve , PID parameters: CURVE intake temperature = f(T2 , T3 , K1 , K2 ) ⑦Continuous monitoring and adjustment: During the entire process, the system will continuously monitor key parameters such as ambient temperature, intake temperature, intercooler temperature, and EGR cooler temperature, and dynamically adjust the throttle opening K3, intercooler bypass opening K1, and EGR valve opening K4 as needed to ensure that the engine can achieve optimal fuel economy and emission performance under various operating conditions.

[0073] Control strategy 2 (EGR bypass and intercooler bypass can be controlled independently) like Figure 4 As shown, the specific control method can be summarized into the following steps: ①Ambient temperature judgment: First, the system detects the current ambient temperature T amb If T amb ≤ 0°C, special condition processing is performed: the intercooler bypass is turned on to ensure that the cooling effect does not affect the engine operation due to the low ambient temperature; at the same time, the EGR system is turned on by default to optimize the combustion efficiency in low temperature environment.

[0074] ②Determine the target parameters: According to the current engine operating conditions (such as speed, load, etc.) and ambient temperature T amb , determine the target intake volume and intake temperature target value T1. At the same time, decide whether to open the EGR system. Since there is no linkage between the EGR channel and the intercooler channel valve plate in the three-way butterfly valve, if it is opened, T1 is achieved by the precise control of the EGR bypass circuit, and the intercooler bypass opening K2 remains unchanged; if it is not opened, the intercooler bypass opening K2 changes in real time, T1 is achieved by the precise control of the intercooler bypass circuit, and the EGR valve always remains closed.

[0075] ③Throttle and EGR valve opening adjustment: Based on the determined target intake air volume and the current ambient temperature T amb First, the throttle opening K1 is calculated and adjusted to meet the target intake volume. Then, according to the actual intercooler temperature T2 and other related factors (such as exhaust temperature, exhaust pressure, etc.), the EGR valve opening K3 is calculated and adjusted to control the flow of recirculated exhaust gas.

[0076] ④Intercooler bypass control: For intercooler bypass, if the ambient temperature is below 0°C and the system needs to adjust the temperature after intercooling (T2), the opening of the three-way butterfly valve or four-way butterfly valve (intercooler bypass side) is controlled through a closed loop to achieve the target mixing temperature T2 , thereby reaching the target intake air temperature T1.

[0077] ⑤ EGR cooler bypass control: For the EGR cooler bypass, the opening of the three-way butterfly valve or the four-way butterfly valve (EGR bypass side) is also controlled through a closed loop. According to the intake temperature target value T1, the real-time monitored intercooler temperature T2, and the EGR valve opening K3, the temperature after the EGR cooler is inferred and the bypass volume is adjusted to achieve the target mixing temperature T3, optimize the temperature of the EGR exhaust gas, and improve the combustion efficiency.

[0078] ⑥Continuous monitoring and adjustment: During the entire process, the system will continuously monitor key parameters such as ambient temperature, intake temperature, intercooler temperature, and EGR cooler temperature, and dynamically adjust the throttle opening K1, intercooler bypass opening K2 (if the intercooler bypass is not closed), and EGR valve opening K3 as needed to ensure that the engine can achieve optimal fuel economy and emission performance under various operating conditions.

[0079] The present invention has a high degree of integration. The design using a multi-way butterfly valve such as a three-way butterfly valve or a four-way butterfly valve is often more compact and can be more easily integrated with other system components (such as an EGR cooler, an EGR valve, an intercooler, etc.), which can significantly reduce the length and complexity of the bypass line. This not only helps to save valuable engine compartment space, but also reduces the difficulty and cost of pipeline layout. This high degree of integration not only reduces system complexity, but also improves the reliability and maintainability of the overall system. By closely combining a multi-way butterfly valve such as a three-way butterfly valve or a four-way butterfly valve with the EGR cooler and intercooler circuits, a functionally complete and compact overall module can be formed. This modular design simplifies the installation process and improves the overall performance and reliability of the system. At the same time, it also facilitates subsequent maintenance and replacement work because the entire module can be disassembled and assembled as a whole.

[0080] Although two traditional solenoid valves can also play a role in the EGR bypass system, their size and shape may limit the close integration with other components, thus affecting the overall layout and efficiency of the system. Traditional solenoid valves may require additional pipes and connectors to connect the EGR cooler and the EGR valve, which increases the complexity and space occupied by the system. Because the connection between the traditional solenoid valve and the EGR cooler is usually loose, it is difficult to achieve a high degree of modularity. This may result in more time and manpower investment during installation, maintenance and replacement.

[0081] In addition, multi-way butterfly valves such as three-way butterfly valves or four-way butterfly valves have better flow regulation performance and can more accurately control the mixing ratio of hot and cold gases in different air chambers and the amount of exhaust gas recirculation. Simple structure, high reliability, and reduced cost: The design of one drive shaft controlling three or four valve plates greatly simplifies the structure, improves the reliability and stability of the system, and reduces manufacturing costs compared to the traditional method of independent control of multiple valve plates. Wide range of applications: The integrated cooling function enables the throttle valve to handle high-temperature and low-temperature gases at the same time, broadening the scope of application. Small gas flow resistance: By adjusting the channel diameter and the valve plate opening, the gas flow resistance can be accurately controlled to improve the throttling efficiency.

[0082] This is essential for optimizing engine performance and reducing emissions. The exhaust gas in the EGR system is hot and may contain corrosive substances. Multi-way butterfly valves such as three-way butterfly valves or four-way butterfly valves are usually made of high-temperature and corrosion-resistant materials to ensure long-term stable operation.

[0083] The present invention has the following beneficial effects: Improve emission performance: Effectively reduce NOx emissions by precisely controlling the mixing ratio and recirculation amount of exhaust gas.

[0084] Optimize engine performance: While maintaining low emissions, the engine combustion process is optimized by adjusting the exhaust gas recirculation volume, improving fuel economy and power performance. During the low-load or cold start stage of the engine, the exhaust gas temperature is low. If all the exhaust gas is cooled by the EGR cooler or intercooler, the gas temperature may be too low, which may cause ice or blockage in the intake system. The three-way butterfly valve reduces the proportion of low-temperature gas by increasing the flow of the bypass branch, avoiding the cooling medium from staying in the heat exchanger for a long time, thereby reducing the risk of ice or freezing and protecting the safety of components. In addition, by adjusting the temperature of the mixed gas, the three-way butterfly valve also indirectly affects the temperature and heat capacity of the mixed gas entering the cylinder, which helps to optimize the combustion process and improve the fuel economy and emission performance of the engine.

[0085] Enhanced system flexibility: This technical solution allows flexible adjustment of intake and exhaust gas treatment strategies according to different engine operating conditions and emission requirements.

[0086] By bypassing the intercooler, the pressurized air can bypass the intercooler and enter the engine directly, thus avoiding the problem of too low intake temperature.

[0087] The control device for the engine intercooler bypass and the EGR cooler bypass provided by the present invention is introduced in detail above. Specific examples are used herein to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and the scope of application. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A control device for engine intercooler bypass and EGR cooler bypass, characterized in that: include: A multi-way butterfly valve is provided with at least three air flow channels, and the input end is connected to the supercharger; An EGR cooler is arranged on an EGR cooling branch, one end of the EGR cooling branch is connected to the EGR circuit, and the other end of the EGR cooling branch is connected to the intake manifold; An EGR bypass branch, one end of which is connected to the EGR circuit through the first air flow channel of the multi-way butterfly valve, and the other end of which is connected to the EGR cooling branch and is located between the EGR cooler and the intake manifold; An intercooler bypass branch, one end of which is connected to the intake manifold, and the other end of which is connected to the second air flow channel of the multi-way butterfly valve; The intercooler has one end connected to the intake manifold and the other end connected to the third air flow channel of the multi-way butterfly valve.

2. The engine intercooler bypass and EGR cooler bypass control device according to claim 1, characterized in that: The EGR cooling branch is also connected to the fourth channel of the multi-way butterfly valve.

3. The engine intercooler bypass and EGR cooler bypass control device according to claim 1, characterized in that: Also includes: An EGR valve is arranged on the EGR cooling branch and is located between the EGR cooler and the intake manifold; The throttle valve is arranged at the entrance of the intake manifold.

4. The control device for engine intercooler bypass and EGR cooler bypass according to claim 3, characterized in that: Also includes: The engine control unit is used to adjust the opening of the EGR valve based on the engine speed, load and temperature to control the recirculation amount of the exhaust gas.

5. The engine intercooler bypass and EGR cooler bypass control device according to claim 4, characterized in that: The engine control unit is also used to control at least one of the first air flow channel and the second air flow channel of the multi-way butterfly valve to open when the ambient temperature of the engine is less than or equal to a preset temperature threshold.

6. The engine intercooler bypass and EGR cooler bypass control device according to claim 4, characterized in that: The engine control unit is also used to determine the target intake temperature based on the engine operating conditions and the ambient temperature of the engine, and to determine whether the EGR valve is closed based on the target intake temperature and the target intercooler after-temperature. When the EGR valve is closed, the opening of the multi-way butterfly valve is adjusted to achieve the target intercooler after-temperature. When the EGR valve is open, the opening of the multi-way butterfly valve is adjusted to achieve the target intake temperature.

7. The control device for engine intercooler bypass and EGR cooler bypass according to claim 6, characterized in that: When the EGR valve is closed, adjust the opening of the multi-way butterfly valve to achieve the target intercooler after-temperature, including: When the EGR valve is closed, the throttle opening is determined based on the target intake volume to adjust the throttle, and the target intercooler after temperature is determined based on the target intake temperature. The target intercooler after temperature is used as the control target, and the opening of the multi-way butterfly valve is adjusted to achieve the target intercooler after temperature.

8. The engine intercooler bypass and EGR cooler bypass control device according to claim 6, characterized in that: When the EGR valve is open, adjust the opening of the multi-way butterfly valve to achieve the target intake air temperature, including: When the EGR valve is opened, the throttle opening and the EGR valve opening are determined based on the target intake volume to adjust the throttle and the EGR valve, and the opening of the multi-way butterfly valve is adjusted based on the preset openings of the first air flow channel and the second air flow channel, and the target intercooler after-temperature to achieve the target intake temperature.

9. The control device for engine intercooler bypass and EGR cooler bypass according to claim 4, characterized in that: The engine control unit is also used for: When the ambient temperature of the engine is less than or equal to a preset temperature threshold, based on the current operating condition of the engine and the ambient temperature, a target intake air volume, a target intake air temperature and an opening of the second air flow channel of the multi-way butterfly valve are determined, and a throttle opening and an EGR valve opening are determined based on the target intake air volume; Determine the target mixture temperature after the EGR cooler based on the target intake air temperature and the real-time monitored intercooler post-temperature and EGR valve opening; Adjust the opening of the multi-way butterfly valve to adjust the temperature after the EGR cooler to the target mixing temperature after the EGR cooler.

10. The engine intercooler bypass and EGR cooler bypass control device according to claim 4, characterized in that: The engine control unit is also used for: When the ambient temperature of the engine is less than a preset temperature threshold, the second air flow channel of the multi-way butterfly valve is controlled to open, and when the EGR valve is not opened, the throttle opening and the target intercooler after-temperature are determined based on the current operating conditions of the engine and the ambient temperature; Adjust the opening of the multi-way butterfly valve to achieve the target intercooler after-temperature.

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