Variable air inlet snow blocking mechanism and air inlet control method

Abstract

The invention discloses a variable air inlet snow blocking mechanism, and belongs to the technical field of automobile engine air inlet systems. The dual-channel air inlet switching structure based on environment temperature triggering is provided for solving the problems that air inlet fails due to the fact that an air filter is blocked by snowflakes in a cold snowfall environment, and combustion is unstable possibly due to low-temperature air inlet. The mechanism comprises an air inlet shell, a rotating baffle, a rotating shaft, an actuator and a temperature sensing unit, the shell is provided with a first air inlet communicated with the atmosphere and a second air inlet communicated with an engine compartment; the rotary baffle is driven by the actuator to rotate around the shaft, and the conduction state of the two air inlets is switched. When the environment temperature is smaller than or equal to 0 DEG C, a physical snow screening barrier is formed through control over the width of the forward gap and the width of the lateral gap of the engine compartment, the effective snow blocking function is achieved during cold starting, and the air inlet temperature is increased synchronously to restrain the unstable combustion phenomenon. The mechanism is an independent detachable module, is quick in response, is suitable for fuel vehicles and hybrid power vehicles, and gives consideration to reliability and platform adaptability.

Description

Technical Field

[0001] This invention relates to the field of automotive engine intake system technology, and in particular to a variable intake snow-blocking mechanism, specifically to the structural design of the snow-blocking mechanism, the switching of the intake path, and its correlation with engine combustion performance optimization. Background Technology

[0002] With the rapid development of new energy vehicles and the continued demand for performance optimization in winter for traditional fuel vehicles, the environmental adaptability of vehicle intake systems has become one of the key technical issues restricting engine reliability and economy. In cold winters, especially in snowy conditions, the intake system continuously draws in a large amount of air mixed with snowflakes when the vehicle is in motion. These snowflakes, after entering the intake duct with the airflow, gradually accumulate on the surface of the air filter, causing filter blockage, a sharp increase in intake resistance, and consequently, a decrease in engine combustion efficiency, limited power output, and in extreme cases, even engine stalling, seriously affecting driving safety and user experience. This problem is particularly prominent in new energy range-extended vehicles or high-performance fuel vehicles, because their power systems are more sensitive to intake air quality.

[0003] Traditional air intake systems employ a single, fixed intake channel design. The intake housing is fixedly mounted between the vehicle's front bumper and the engine compartment, with its front end directly connected to the atmosphere and its rear end connected to the air filter and engine via an intake pipe. The essential function of this structure is to provide the engine with a stable, low-resistance air source. Its design philosophy always adheres to the principle of "direct access to the atmosphere and shortest path" to ensure optimal charging efficiency. In long-term engineering practice, this structure has been widely used due to its simplicity, reliability, and low cost, constituting the mainstream technology in air intake system design.

[0004] Existing technologies have the following shortcomings. First, in blizzards or wet snow, snowflakes can easily clog air filters, leading to intake failure. Simultaneously, in extremely cold environments (e.g., ≤0℃), excessively low intake air temperatures can cause poor fuel atomization and uneven air-fuel mixture formation, resulting in unstable combustion or abnormal ignition. Second, even with an alternative intake path, if relying on a heat source to melt snow, reliable snow blocking is still impossible under low-temperature conditions such as cold starts and long downhill coasting. Third, existing solutions generally treat the intake system as an independent air delivery unit, failing to deeply couple it with improving combustion conditions, thus missing the opportunity to utilize intake air temperature to improve combustion. Finally, the intake switching mechanism is strongly coupled with the cooling module, making it difficult to adapt to existing vehicle models. Furthermore, the dispersed sensor-execution architecture results in significant response latency, hindering modular integration.

[0005] Introducing warmer engine compartment air can improve the quality of the air-fuel mixture and enhance combustion reliability during cold operation.

[0006] Early automotive intake system designs focused on minimizing flow resistance and improving filtration efficiency. When snow protection functions were later introduced, the traditional approach of "passive protection + thermal snow melting" was still followed. In the field of winter snow entry, a more advanced technical approach is to use temperature sensors to trigger damper switching, and introduce cabin air heated by a heat exchanger through an air guide system. This approach utilizes the phenomenon of "no ice in the air after snow melting" to achieve the protection purpose. However, this solution is not designed in conjunction with improving combustion conditions. On the one hand, the surface absorbs a large amount of heat due to phase change when the snow melts in the engine compartment. On the other hand, the gaps in the engine compartment lack targeted control, resulting in a large amount of convective heat exchange between the engine compartment and the outside. The amount of gas entering the engine compartment is also unrestricted. These factors together lead to a large amount of heat loss in the engine compartment, and the heat in the engine compartment cannot be better utilized to improve combustion conditions while melting snow.

[0007] Existing technologies focus on the single protective objective of "preventing air filter icing," and their snow-blocking mechanisms rely on waste heat from heat exchangers, resulting in insufficient reliability when the engine is not fully warmed up. Furthermore, they fail to recognize that low-temperature intake air exacerbates combustion instability and fail to incorporate intake air temperature control into the combustion optimization system. In contrast, this patent application establishes a technical approach that couples the dual functions of snow blocking and improved combustion conditions through physical snow sieving and the utilization of native cabin hot air.

[0008] The aforementioned shortcomings collectively underscore the necessity of this invention. As engines evolve towards higher compression ratios and smaller sizes, improving combustion conditions has become one of the bottlenecks limiting performance improvement, especially in low-temperature winter environments where the intake of supercooled air significantly exacerbates combustion instability. Simultaneously, users are increasingly demanding higher reliability across all operating conditions, ease of maintenance, and platform compatibility. Therefore, there is an urgent need for a variable intake snow-blocking mechanism that can reliably block snow under all operating conditions through physical snow-sieving mechanisms, actively utilizes the engine compartment's native hot air to improve combustion conditions, and possesses modular, plug-and-play characteristics. This would address the fundamental shortcomings of existing technologies, such as limited functionality, reliance on thermal engine conditions for reliability, high system coupling, and slow response speed. Summary of the Invention

[0009] The purpose of this invention is to provide a technology that can reliably block snow and improve combustion conditions simultaneously by switching the air intake path in low-temperature environments, in order to overcome the defects of existing technologies, such as the failure of protection and the decrease in combustion stability under cold start conditions caused by the snow blocking mechanism relying on heat sources to melt snow and the functional goal being limited to single protection.

[0010] To achieve the above objectives, the variable air intake snow-blocking mechanism of the present invention is used in a vehicle engine air intake system, including an air intake housing, a rotating baffle, a rotating shaft, an actuator, and a temperature sensing unit. The air intake housing is provided with a first air intake that communicates with the atmosphere and a second air intake that communicates with the engine compartment; the rotating baffle is disposed inside the air intake housing and connected to the rotating shaft; the rotating baffle switches the communication state between the first air intake or the second air intake and the downstream air intake pipeline by rotating around the rotating shaft. The actuator is fixed to the outside of the air inlet housing and drives the rotating shaft to rotate; the temperature sensing unit is used to detect the ambient temperature and triggers the actuator to act when the ambient temperature is less than or equal to 0°C, so that the rotating baffle switches to the second air inlet. The second air intake introduces air from the engine compartment. When the engine is running continuously, the air in the engine compartment directly utilizes the heat source of the engine body to achieve a temperature higher than the ambient temperature, so as to simultaneously achieve physical blocking of snowflakes and suppress combustion instability.

[0011] The engine compartment is connected to the outside atmosphere through multiple gaps. These gaps are distributed in the engine compartment wall wiring harness perforations, bracket gaps, pipe interfaces, and the junction between the engine compartment cover and the wall. The gaps include forward gaps, lateral gaps, and downward gaps. The total flow cross-sectional area of ​​all gaps is not less than 70% of the air intake cross-sectional area corresponding to the engine's maximum air intake requirement. The width of the forward gap is less than 0.7 mm, the width of the lateral gap is less than 2.0 mm, and there is no specific limit on the width of the downward gap.

[0012] The temperature sensing unit is embedded inside the actuator housing and integrated with the actuator's control circuit board in the same package housing, with a signal transmission path length not exceeding 50mm.

[0013] The variable air intake snow deflector is independent of the cooling module or air duct system in the engine compartment and is an independent, detachable module.

[0014] The actuator's control circuit board is connected to the temperature sensing unit. The actuator's control circuit board is also connected to a connector for communicating with the vehicle's ECU, and is used to receive control from the vehicle's ECU.

[0015] The rotating baffle is fitted with a sealing strip at its edge, forming a flexible seal with the inner wall of the air inlet housing; the rotating shaft is supported on the side wall of the air inlet housing by a sealed bearing, with one end extending out of the housing and connected to the drive device.

[0016] The present invention also discloses an air intake control method based on the variable air intake snow-blocking mechanism, comprising the following steps: S1: Real-time monitoring of ambient temperature via a temperature sensing unit; S2: Determine if the ambient temperature is ≤0℃; S3: If the judgment result is yes, then control the actuator to drive the rotating baffle to rotate, so that the second air inlet is open and the first air inlet is closed; S4: If the judgment result is negative, keep the first air intake open and the second air intake closed.

[0017] The vehicle ECU can have a built-in dynamic adjustment strategy. Under high engine load and low speed conditions, even if the ambient temperature is ≤0℃, the second air intake will still be maintained to maximize the effect of suppressing combustion instability. Under low engine load and high speed conditions, if insufficient air intake is detected, the system will switch back to the first channel and issue a warning signal.

[0018] The present invention has the following advantages: In low-temperature environments, using intake air that is higher than the external ambient temperature can effectively mitigate the risk of combustion instability caused by overly cold intake air. The air temperature inside the engine compartment, heated by the engine's heat source, is typically 15–30°C higher than the outside temperature, and it is usually above 0°C even when the engine is running continuously and intake air is continuously passing through gaps.

[0019] This invention solves the problem of snow blocking failure under cold start conditions caused by reliance on heat exchangers for snow melting in existing technologies by simultaneously activating the dual functions of snow blocking and better improving combustion conditions under a single low-temperature trigger condition (≤0℃). At the same time, it avoids combustion instability caused by low-temperature atmospheric intake. It can significantly reduce combustion instability and improve winter power responsiveness and fuel economy.

[0020] This invention utilizes the engine compartment structure to form a distributed physical screen (controlling the width of the forward and lateral gaps to prevent most snowflakes from entering the engine compartment). Snowflakes are intercepted on the outside of the gaps, achieving a reliable snow-blocking mechanism of "blocking first, then sucking in". It completely eliminates the dependence on heat sources to melt snow and is effective at the moment of cold start, without having to wait for the engine temperature to rise before melting snow to prevent snow.

[0021] This invention transforms the "incomplete sealing of the engine compartment," which is traditionally considered a manufacturing defect, into a functional advantage (by specifically controlling the width of all forward and lateral gaps and the total cross-sectional area of ​​the gaps), embodying reverse engineering thinking and belonging to a typical unconventional technology.

[0022] The signal transmission path length does not exceed 50mm, shortening the temperature response delay and improving the switching timeliness when the vehicle enters a low-temperature area (such as a tunnel exit); at the same time, it saves the installation space of wiring harnesses and independent sensors, and is suitable for the narrow layout environment of the front bumper.

[0023] This invention is an independent, detachable module that requires no modification to the cooling module or airflow system in the engine compartment, enabling plug-and-play deployment. It supports aftermarket installation on existing models or platform-based extensions, significantly reducing development costs and time. This invention decouples the strong bond between the intake and cooling systems, overcoming the limitation that snow protection technology can only be developed concurrently with new vehicles.

[0024] The intake control method of this invention has a simple logic, relying solely on a single temperature threshold to simultaneously achieve the goals of snow protection and combustion optimization. It is easily implemented via an ECU, achieving the technical effects of snow protection and improved combustion stability in snowy conditions, and improved combustion stability even in the absence of snow. This intake control method does not rely on GPS, image recognition, or other complex sensing methods, resulting in low cost and strong robustness. The rotating baffle achieves reliable dual-channel switching through a single moving part, featuring a simple structure and low failure rate; the sealing strip design reduces rotational noise while achieving airflow isolation. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0026] Figure 2 This is a schematic diagram of the main structure of the present invention.

[0027] Figure 3 This is the front sectional view of the present invention.

[0028] Figure 4 yes Figure 2 AA sectional view.

[0029] Figure 5 yes Figure 3 Enlarged view of point A in the middle. Detailed Implementation

[0030] like Figures 1 to 5 As shown, the variable air intake snow-blocking mechanism of the present invention is used in the vehicle engine air intake system, including an air intake housing 1, a rotating baffle 2, a rotating shaft 3, an actuator 4, and a temperature sensing unit 5; The air intake housing 1 is provided with a first air intake 6 that communicates with the atmosphere and a second air intake 7 that communicates with the engine compartment; the rotating baffle 2 is disposed inside the air intake housing 1 and connected to the rotating shaft 3; the rotating baffle 2 switches the communication state between the first air intake 6 or the second air intake 7 and the downstream air intake pipeline by rotating around the rotating shaft 3. The actuator 4 is fixed to the outside of the air inlet housing 1 and drives the rotating shaft 3 to rotate; the temperature sensing unit 5 is used to detect the ambient temperature and trigger the actuator 4 to act when the ambient temperature is less than or equal to 0°C, so that the rotating baffle 2 switches to the second air inlet 7. The second air intake 7 introduces engine compartment air. When the engine is running continuously, the engine compartment air is not heated by a heat exchanger, but directly uses the engine body heat source to achieve a temperature higher than the ambient temperature, so as to simultaneously achieve physical isolation of snowflakes and better suppress combustion instability of the engine.

[0031] The air intake housing 1 is a hollow housing formed by injection molding or die casting. The front opening is divided into upper and lower sections. The upper section is the atmospheric passage inlet, and the lower section is connected to the internal space of the engine compartment through a guide pipe or directly. The rotating baffle 2 is installed in the internal cavity of the housing. The rotating shaft 3 is a metal shaft, one end of which is fixedly connected to the rotating baffle 2, and the other end passes through the housing wall and is coaxially connected to the output shaft of the actuator 4. The actuator 4 adopts a micro motor or stepper motor, and the control circuit board is built into the housing 8 of the actuator 4. The temperature sensing unit 5 can be an NTC thermistor or a digital temperature sensor, which is installed on the vehicle to measure the ambient temperature.

[0032] In low-temperature environments, using intake air that is higher than the external ambient temperature can effectively mitigate the risk of combustion instability caused by overly cold intake air. The air temperature inside the engine compartment, heated by the engine's heat source, is typically 15–30°C higher than the outside temperature, and even when the engine is running continuously, the temperature is usually above 0°C under conditions of continuous air intake through gaps.

[0033] This invention solves the problem of snow blocking failure under cold start conditions caused by reliance on heat exchangers for snow melting in existing technologies by simultaneously activating the dual functions of snow blocking and better suppressing combustion instability under a single low-temperature trigger condition (≤0℃). At the same time, it avoids combustion instability caused by low-temperature atmospheric intake. It can significantly reduce the risk of combustion instability and improve winter power responsiveness and fuel economy.

[0034] The conclusion that the air temperature inside the engine compartment is higher than the ambient temperature applies to conditions where the engine has been running for at least 3 minutes or the vehicle is in motion. In the initial stage of a cold start (<30 seconds), the temperature inside the compartment may be close to the ambient temperature because the heat source is not activated. However, the main application scenario of this mechanism is continuous vehicle operation rather than the initial start-up of the vehicle, so it does not affect the overall functional reliability.

[0035] This solution is applicable to fuel vehicles, range-extended electric vehicles, and plug-in hybrid vehicles; the second air intake 7 does not pass through heat exchange components such as radiators and condensers, but directly draws air from the rear of the engine compartment, resulting in high air cleanliness and no risk of coolant vapor pollution.

[0036] The ambient temperature threshold of 0℃ is the design parameter. Under the premise of the structure of this invention, the need to suppress combustion instability is also taken into account. Bench tests have verified that switching at this threshold can balance the reliability of snow blocking and better suppress combustion instability.

[0037] The engine compartment is connected to the outside atmosphere through multiple gaps. These gaps are distributed in the engine compartment wall wiring harness perforations, bracket gaps, pipe interfaces, and the junction between the engine hood and the engine compartment wall. These gaps include forward gaps (gap facing the vehicle's forward direction), lateral gaps, and downward gaps. The total flow cross-sectional area of ​​all gaps is not less than 70% of the intake cross-sectional area corresponding to the engine's maximum intake demand. This limits the total airflow and reduces convective heat transfer, maintaining a relatively high temperature inside the engine compartment in low-temperature environments. This helps suppress combustion instability and meets the vehicle's continuous driving requirements on flat roads. The width of the forward gap is less than 0.7 mm, the lateral gap is less than 2.0 mm, and there are no specific restrictions on the downward gap.

[0038] In this invention, "engine compartment bulkhead" refers to the metal load-bearing wall panel that constitutes the main structure of the engine compartment, mainly including the front firewall, left and right side panels, and the bottom reinforcing beam area, used to support the powertrain, cooling module, and wiring harness bracket. The lateral and downward gaps are the main channels for air intake in the engine compartment.

[0039] The connection between the engine hood (i.e., the front hood) and the bulkhead is typically equipped with a rubber sealing strip to prevent excessive intrusion of rainwater and dust and to reduce wind noise. However, due to assembly tolerances, thermal deformation compensation, and cost control considerations, this sealing structure does not aim for complete airtightness. In actual use, a small flow gap (typically 0.2–1 mm wide) is still retained to allow air to pass slowly under pressure differential. Combined with gaps at wiring harness perforations, bracket gaps, and pipe interfaces, these naturally occurring gaps are distributed in the front, side, and bottom areas of the engine compartment. This invention controls the total cross-sectional area of ​​these gaps, so that they collectively constitute an effective air intake source for the second air intake 7.

[0040] The gap control in this invention is sufficient to support the snow-blocking and combustion instability suppression functions under typical operating conditions, especially perfectly matching cold start and low-to-medium load scenarios (scenarios where the vehicle is not overloaded and does not involve continuous driving on long uphill sections fall under low-to-medium load scenarios). Under high load, the system can switch back to the first air intake 6 through a control strategy to ensure system robustness. While increasing the width of the downward gap could enhance the engine compartment's air intake capacity at low temperatures, it would also lower the temperature inside the engine compartment, which is detrimental to the design goal of suppressing combustion instability. Therefore, this invention sets the total flow cross-sectional area of ​​all gaps to no less than 70% of the air intake cross-sectional area corresponding to the engine's maximum air intake requirement (matching low-to-medium load scenarios, which are also the majority of vehicle usage conditions, minimizing heat loss from the engine compartment and maintaining a relatively high temperature inside the engine compartment), rather than arbitrarily increasing the area of ​​the downward gap (to enhance convective heat transfer). Under high load, the system can switch to air intake through the first air intake 6 through an ECU control strategy.

[0041] This invention utilizes the engine compartment structure to form a distributed physical screen (controlling the width of the forward and lateral gaps to prevent most snowflakes from entering the engine compartment). Snowflakes are intercepted on the outside of the gaps, achieving a reliable snow-blocking mechanism of "blocking first, then sucking in". It completely eliminates the dependence on heat sources to melt snow and is effective at the moment of cold start, without having to wait for the engine temperature to rise before melting snow to prevent snow.

[0042] This invention transforms the "incomplete sealing of the engine compartment," which is traditionally considered a manufacturing defect, into a functional advantage (by specifically controlling the width of all forward and lateral gaps and the total cross-sectional area of ​​the gaps), embodying reverse engineering thinking and belonging to a typical unconventional technology.

[0043] In this invention, the design concept of limiting the gap width and the total cross-sectional area is to balance the suppression of unstable combustion (blocking most snowflakes from entering the engine compartment and avoiding snow melting and cooling) and air intake (the total area of ​​the gaps connecting the engine compartment to the outside meets 70% of the vehicle's maximum air intake requirements).

[0044] If the total area of ​​the gap is too small, it will cause poor air intake to the engine and fail to meet the requirements for normal continuous driving at low temperatures. Therefore, no specific limit is placed on the width of the downward gap to ensure that the total area of ​​the gap is controllable, and snowflakes will not enter the engine compartment from here.

[0045] If too much snow enters the engine compartment, the melting snow will lower the temperature inside the compartment, which is detrimental to suppressing combustion instability. Snow is more likely to enter through forward gaps, followed by side gaps. Therefore, this invention strictly limits the width of the forward gaps while correspondingly relaxing the width limit for the side gaps. Limiting snow entry into the engine compartment is not only to prevent air filter blockage, but also to avoid excessive temperature drops in the engine compartment due to melting snow, which would be detrimental to suppressing combustion instability (a synergistic design of anti-blockage and combustion suppression).

[0046] The temperature sensing unit 5 is embedded inside the housing 8 of the actuator 4 and is integrated with the control circuit board of the actuator 4 in the same package housing. The signal transmission path length does not exceed 50mm.

[0047] The temperature sensing unit 5 is embedded inside the actuator 4, which is only an optional installation location for the temperature sensing unit 5 (if the position of the actuator 4 is suitable for measuring the ambient temperature), and is not a necessary installation location. The necessary installation location for the temperature sensing unit 5 is still based on its suitability for measuring the ambient temperature.

[0048] The signal transmission path length does not exceed 50mm, shortening the temperature response delay and improving the switching timeliness when the vehicle enters a low-temperature area (such as a tunnel exit); at the same time, it saves the installation space of wiring harnesses and independent sensors, and is suitable for the narrow layout environment of the front bumper.

[0049] The variable air intake snow deflector is independent of the cooling module or airflow system in the engine compartment and is a detachable module. As a detachable module, it requires no modification to the cooling module or airflow system in the engine compartment, enabling plug-and-play deployment. It supports aftermarket installation on existing models or platform-based extensions, significantly reducing development costs and time. This invention decouples the strong bond between the air intake and cooling systems, overcoming the limitation that snow protection technology can only be developed concurrently with new vehicles.

[0050] The control circuit board of actuator 4 is connected to the temperature sensing unit 5. The control circuit board of actuator 4 is also connected to a connector 9 for communicating with the vehicle ECU, which is used to receive control from the vehicle ECU.

[0051] The rotating baffle 2 is fitted with a sealing strip at its edge, forming a flexible seal with the inner wall of the air inlet housing 1; the rotating shaft 3 is supported on the side wall of the air inlet housing 1 by a sealed bearing, and one end extends out of the housing and is connected to the drive device.

[0052] The present invention also discloses an air intake control method based on the variable air intake snow-blocking mechanism, comprising the following steps: S1: Real-time monitoring of ambient temperature via temperature sensing unit 5; S2: Determine if the ambient temperature is ≤0℃; S3: If the judgment result is yes, then control the actuator 4 to drive the rotating baffle 2 to rotate, so that the second air inlet 7 is open and the first air inlet 6 is closed; S4: If the judgment result is negative, then keep the first air intake 6 open and the second air intake 7 closed.

[0053] The judgment and execution cycle of steps S2–S3 is ≤100ms; a 3℃ hysteresis logic can be added to prevent frequent switching. The 3℃ hysteresis means that: the second air intake 7 is turned on when it is below Tlow=0℃; it is turned off and the first air intake 6 is turned on when it is above Thigh=Tlow+3℃; the original state remains unchanged between the two (Tlow~Thigh).

[0054] The intake control method of this invention has a simple logic, achieving both snow protection and combustion optimization goals simultaneously using only a single temperature threshold, and is easily implemented through an ECU. This intake control method does not rely on GPS, image recognition, or other complex sensing methods, making it low-cost and robust.

[0055] The sealing strip is made of ethylene propylene diene monomer (EPDM) rubber with a thickness of 2mm; the sealing bearing is made of stainless steel.

[0056] The rotating baffle 2 achieves reliable switching between two channels through a single moving part, with a simple structure and low failure rate; the sealing strip design reduces rotation noise while achieving airflow isolation.

[0057] The vehicle ECU can have a built-in dynamic adjustment strategy. Under high engine load and low speed conditions, even if the ambient temperature is ≤0℃, the second air intake 7 will be maintained first to maximize the effect of suppressing combustion instability. Under low engine load and high speed conditions, if insufficient air intake is detected, the system will switch back to the first channel and issue a warning signal.

[0058] Working in conjunction with the ECU makes the intake switching more aligned with actual driving needs, avoiding insufficient intake volume under extreme conditions; dynamic strategies enhance the system's intelligence level and adaptability to different operating conditions.

[0059] Using this invention, during normal operation, the intake air temperature at the second air intake 7 is at least 5-10°C higher than the ambient temperature, which helps to suppress combustion instability. The intake air temperature difference is provided by the waste heat in the engine compartment, eliminating the need for additional heating and improving combustion stability.

[0060] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A variable inlet snow shield mechanism for a vehicle engine air intake system, characterized by: The variable air intake snow blocking mechanism comprises an air inlet housing, a rotating baffle, a rotating shaft, an actuator and a temperature sensing unit. The air inlet housing is provided with a first air inlet connected to the atmosphere and a second air inlet connected to the engine compartment; the rotating baffle is arranged in the air inlet housing and connected to the rotating shaft; the rotating baffle switches the communication state between the first air inlet or the second air inlet and the downstream air inlet pipeline by rotating around the rotating shaft. The actuator is fixed outside the air inlet housing and drives the rotating shaft to rotate; the temperature sensing unit is used to detect the ambient temperature and trigger the actuator to act when the ambient temperature is less than or equal to 0℃, so as to switch the rotating baffle to the second air inlet. The second air inlet introduces engine compartment air, which is directly heated by the engine body heat source when the engine is continuously working, so as to be higher than the ambient temperature, thereby synchronously realizing snowflake physical blocking and suppressing combustion instability.

2. The variable inlet shutter mechanism of claim 1, wherein: The engine compartment is connected to the external atmosphere through multiple gaps, which are distributed at the wire harness perforations of the cabin wall of the engine compartment, the gaps between supports, the pipeline interfaces and the joint between the engine compartment cover and the cabin wall, and the gaps include forward gaps, lateral gaps and downward gaps; the total flow area of all gaps is not less than 70% of the maximum air intake area required by the engine. The width of the forward gap is less than 0.7mm, the width of the lateral gap is less than 2.0mm, and the width of the downward gap is not specifically limited.

3. The variable inlet shutter mechanism of claim 1, wherein: The temperature sensing unit is embedded in the actuator housing and integrated with the control circuit board of the actuator in the same packaging housing, and the signal transmission path length is not more than 50mm.

4. The variable inlet shutter mechanism of claim 1, wherein: The variable air intake snow blocking mechanism is independent of the cooling module or air guiding system in the engine compartment and is an independent detachable module.

5. The variable inlet shutter mechanism of claim 1, wherein: The control circuit board of the actuator is connected to the temperature sensing unit, and the control circuit board of the actuator is also connected to a connector for communication with the vehicle-mounted ECU for receiving the control of the vehicle-mounted ECU.

6. The variable inlet shutter mechanism of claim 5, wherein: The rotating baffle edge is embedded with a sealing strip to form a flexible seal with the inner wall of the air inlet housing; the rotating shaft is supported on the side wall of the air inlet housing through a sealing bearing and extends out of the housing to be connected to the driving device.

7. An air intake control method based on the variable intake shutter mechanism according to any one of claims 1-4, characterized by, The method comprises the following steps: S1: real-time monitoring of the ambient temperature by the temperature sensing unit; S2: judging whether the ambient temperature is ≤0℃; S3: if the result is yes, controlling the actuator to drive the rotating baffle to rotate, so as to make the second air inlet conductive and the first air inlet closed; S4: if the result is no, keeping the first air inlet conductive and the second air inlet closed.

8. The intake control method according to claim 7, characterized by: The vehicle-mounted ECU can have a dynamic adjustment strategy, which can keep the second air inlet to maximize the effect of suppressing combustion instability even if the ambient temperature is ≤0℃ under high load and low speed working conditions of the engine; under low load and high speed working conditions of the engine, if the intake air is insufficient, the first channel is switched back and a warning signal is sent.

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