Variable inlet snow baffle mechanism

Abstract

The utility model discloses a variable intake port snow blocking mechanism belongs to automobile engine intake system technical field. In view of the problem that snowflake blocks air cleaner and leads to air intake failure under cold and snow environment, and low temperature intake may lead to unstable combustion, a double-channel intake switching structure based on ambient temperature triggering is provided. 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 connected to the atmosphere and a second air inlet connected to the engine compartment; the rotating baffle is driven to rotate around the shaft by the actuator, and the conduction state of the two air inlets is switched; when the ambient temperature is less than or equal to 0 DEG C, a physical snow screening barrier is formed by controlling the width of the front and lateral gaps of the engine compartment, effectively blocking snow during cold start, and the intake temperature is simultaneously raised to suppress unstable combustion. The mechanism is an independent detachable module, responds quickly, is suitable for fuel vehicles and hybrid vehicles, and takes into account reliability and platform adaptability.

Description

Technical Field

[0001] This utility model relates to the technical field of automotive engine intake systems, and in particular to a variable intake snow-blocking mechanism, specifically pointing 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 highlight the necessity for improvement in this utility model. As engines evolve towards higher compression ratios and smaller sizes, improving combustion conditions has become one of the bottlenecks limiting performance enhancements. This is especially true 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 a physical snow-sieving mechanism, actively utilize the engine compartment's native hot air to improve combustion conditions, and possess 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. Utility Model Content

[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 that result in protection failure and decreased combustion stability under cold start conditions due to the snow blocking mechanism relying on heat sources to melt snow and the functional objective being limited to single protection.

[0010] To achieve the above objectives, the variable air intake snow-blocking mechanism of this utility model is used in the 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.

[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] This utility model has the following advantages: This invention solves the problem of snow-blocking failure under cold start conditions caused by reliance on heat exchangers for snow melting in the prior art, while avoiding combustion instability caused by low-temperature atmospheric intake; it can significantly reduce combustion instability and improve winter power responsiveness and fuel economy.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] This utility model 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 utility model 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.

[0021] The rotating baffle achieves reliable switching between two channels through a single moving part, with a simple structure and low failure rate; the sealing strip design reduces rotational noise while isolating airflow. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0023] Figure 2 This is a schematic diagram of the main structure of this utility model.

[0024] Figure 3 This is the front sectional view of this utility model.

[0025] Figure 4 yes Figure 2 AA sectional view.

[0026] Figure 5 yes Figure 3 Enlarged view of point A in the middle. Detailed Implementation

[0027] like Figures 1 to 5 As shown, the variable air intake snow-blocking mechanism of this utility model 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.

[0028] The 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 fixed 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.

[0029] 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.

[0030] This invention solves the problem of snow-blocking failure during cold start conditions caused by reliance on heat exchangers for snow melting in the prior art (the temperature is low during cold start, and snow cannot be melted), while avoiding 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.

[0031] 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 of the vehicle, so it does not affect the overall functional reliability.

[0032] 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.

[0033] The ambient temperature threshold of 0℃ is the design parameter. Under the premise of the structure of this utility model, 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.

[0034] 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.

[0035] 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.

[0036] The connection between the engine hood (i.e., the front cover) and the bulkhead is usually 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 existing 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.

[0037] 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 port 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 port 6 through an ECU control strategy.

[0038] 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.

[0039] 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.

[0040] In this utility model, 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 gap connecting the engine compartment and the outside world meets 70% of the vehicle's maximum air intake requirements).

[0041] 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.

[0042] If too much snow enters the engine compartment, the melting snow will lower the temperature inside the engine compartment, which is detrimental to suppressing combustion instability. Snow is more likely to enter through the forward gaps, followed by the 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 the air filter from clogging, but also to avoid excessive cooling of the engine compartment due to the melting of a large amount of snow, which is detrimental to suppressing combustion instability (a synergistic design of anti-clogging and combustion suppression).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In use, this utility model receives control from the vehicle ECU via connector 9, but the vehicle ECU is not part of this utility model. Under normal circumstances, the first air intake 6 remains open and the second air intake 7 remains closed. The vehicle ECU monitors the ambient temperature in real time via temperature sensing unit 5. When the temperature is below 0℃, the vehicle ECU controls actuator 4 to drive the rotating baffle 2 to rotate, thus opening the second air intake 7 and closing the first air intake 6. This achieves the technical effect of snow prevention in snowy conditions and improved combustion stability in the absence of snow.

[0050] 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.

[0051] 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.

[0052] With 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.

[0053] The above embodiments are only used to illustrate and not limit the technical solutions of this utility model. Although the utility model 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 utility model without departing from the spirit and scope of the utility model. Any modifications or partial substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A variable air intake snow deflector mechanism for use in a vehicle engine intake system, characterized in that: It includes an air inlet 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.

2. The variable air intake snow-blocking mechanism as described in claim 1, characterized in that: 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.

3. The variable air intake snow-blocking mechanism as described in claim 1, characterized in that: 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.

4. The variable air inlet snow-blocking mechanism according to claim 1, characterized in that: 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.

5. The variable air intake snow-blocking mechanism as described in claim 1, characterized in that: 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.

6. The variable air intake snow-blocking mechanism as described in claim 5, characterized in that: 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.

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