A rearview mirror rainwater blowing system based on BCM

Abstract

This invention belongs to the field of automotive technology and relates to a rearview mirror rain removal system based on a BCM. Based on the naturally generated airflow during vehicle operation, an internal flow channel is provided within the rearview mirror to guide high-speed airflow across the mirror surface, thereby effectively removing raindrops. This solution not only directly removes raindrops but also forms an air film on the outside of the rearview mirror to prevent raindrops from entering. The faster the vehicle travels, the better the removal effect. Furthermore, combined with the rearview mirror's direction adjustment system, this system can quickly and effectively remove raindrops adhering to the mirror surface, ensuring driving safety. This solution is simple to implement, requires minimal equipment, is inexpensive, and has a compact structure, making it very easy to quickly implement and retrofit on a vehicle.

Description

Technical Field

[0001] The invention belongs to the technical field of automobiles and relates to a rearview mirror rainwater blowing system based on BCM. Background Art

[0002] Vehicle rearview mirrors are visual devices exposed on the exterior of the vehicle and are crucial for driving safety. However, during rain, water droplets often cling to the mirrors, impairing visibility and compromising driving safety. Because the mirror surface is located on the leeward side of the vehicle, a backflow zone forms, making droplets difficult to remove once they form. Currently, commonly used technologies include electric heating and mirror film defogging. However, in practice, electric heating can only remove mist and has little effect on raindrops. Different types of film products offer varying degrees of effectiveness, and prolonged exposure to sunlight, dust, and oxidation can significantly reduce their effectiveness, increasing user costs. Currently, there is no truly effective system for blowing raindrops off rearview mirrors, resulting in limited success.

[0003] Therefore, there is an urgent need for a rearview mirror rainwater blowing system to solve the above problems. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a rearview mirror rain water blowing off system based on BCM, including a BCM central control unit, a rearview lens angle adjustment motor, a rearview mirror lens, a rearview mirror upper cover and a rearview mirror lower cover, and is characterized in that an air flow channel inner plug is provided between the rearview mirror upper cover and the rearview mirror lower cover, and ventilation channels are respectively left between the air flow channel inner plug and the rearview mirror upper cover and the rearview mirror lower cover, and the side surfaces of the air flow channel inner plug are fixed on the left and right side walls of the rearview mirror; a throttle valve is provided inside the air flow channel inner plug, and the BCM central control unit controls the opening and closing angles of the throttle valve, and controls the on-off of the ventilation channel at the lower end of the air flow channel inner plug.

[0005] Furthermore, the ventilation flow channel is divided into an upper surface of the ventilation flow channel and a lower surface of the ventilation flow channel. The starting section of the upper surface of the ventilation flow channel is a straight line section, and it is a concave configuration at the outlet. The lowest point of the concave configuration is horizontally located above the rotating shaft of the rearview lens angle adjustment motor; the starting section of the lower surface of the ventilation flow channel is a straight line section, and it is a concave configuration at the outlet.

[0006] Furthermore, the angle β between the slope of the outlet curve of the upward concave configuration and the horizontal direction is 30° to 60°; the curvature of the lower surface of the air flow channel is less than 0 in the coordinate system, the slope at the lowest point in the concave configuration is 0, and the distance from the lowest point of the concave configuration to the rotation axis L1 of the rearview lens angle adjustment motor is in the range of 5 to 10 cm.

[0007] Furthermore, the straight line segments of the upper surface of the ventilation flow channel and the lower surface of the ventilation flow channel at the starting section are parallel line segments, and the angle α between the parallel line segments and the horizontal direction is 20° to 40°.

[0008] Furthermore, the air channel inner plug is located at the rear of the straight section of the upper surface of the ventilation channel and the lower surface of the ventilation channel, dividing the upstream airflow into two parts, the upper airflow is the main airflow, and the downstream airflow is the air control flow; on the windward side of the inner plug (3), the inlet area of ​​the upper channel is 4 to 5 times the inlet area of ​​the lower channel, that is, when the throttle valve (5) is opened, the flow rate of the main airflow is about 4-5 times the flow rate of the air control flow, and the total length of the air channel inner plug (3) in the horizontal direction is not less than 10 cm to ensure that the two airflows have different speed characteristics.

[0009] Furthermore, the inner flow channel of the air flow channel inner plug on one side of the lower surface of the ventilation flow channel consists of two parts, one part is a horizontal parallel straight line segment, and the other part is a parallel straight line segment with an angle γ of 30° to 50° to the horizontal direction. On one side of the upper surface of the ventilation flow channel is a curved segment or a broken line segment, and a flow configuration that first contracts and then expands appears between the air flow channel inner plug and the upper surface of the ventilation flow channel.

[0010] Furthermore, the thickness of the tail portion of the upper wall of the rearview mirror upper cover is H1, and the value range of H1 is not less than 3 cm.

[0011] Furthermore, a rain sensor is installed on the front windshield, and the BCM central control unit receives the rain sensor and vehicle speed data.

[0012] Beneficial effects:

[0013] Based on the natural airflow generated during vehicle driving, the present invention sets an internal flow channel inside the rearview mirror to guide high-speed airflow to flush the rearview mirror surface, thereby achieving the effect of blowing away raindrops. The specific performance is as follows:

[0014] 1. Through the design of the concave configuration, when the control airflow passes through the concave surface, due to the smaller control airflow rate and the larger flow channel area, the control airflow forms a recirculation zone at the concave surface under the interaction with the main air flow.

[0015] 2. Inside the recirculation area, the air flow is small and the pressure is high. The main air flow is lifted up by the recirculation air flow. Due to the ingenious design of the structural dimensions, the main air flow changes its original flow direction, deflects upward into the upper concave area, and deflects downward along the wall of the upper concave surface.

[0016] 3. The downward deflected outgoing airflow has a larger angle and a faster speed. Under the action of the Coanda effect, the high-speed outgoing airflow adheres to the wall of the rearview mirror, washing away the raindrops attached to it.

[0017] 4. In conjunction with the flushing of airflow, the rearview lens angle adjustment motor can make regular deflections to improve the flushing effect.

[0018] 5. The upward and downward concave configurations that are staggered in the longitudinal position enable the airflow to have a larger airflow deflection angle in a smaller space.

[0019] 6. The system has two working modes. It can either open the throttle valve to blow away raindrops directly, or close the throttle valve to form an air film on the outside of the rearview mirror to prevent raindrops from entering.

[0020] 7. The faster the driving speed, the better the blowing effect. Combined with the rearview mirror direction adjustment system, it can quickly and effectively blow away raindrops attached to the mirror surface to ensure driving safety.

[0021] 8. This solution is simple, requires minimal equipment, is inexpensive, and has a compact structure. Different models of rearview mirrors only require adjustments to certain geometric parameters to ensure effective cleaning. It is very easy to quickly implement and retrofit on a car. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 Rearview mirror rain water blowing system structure diagram;

[0024] Figure 2 BCM central control unit control diagram;

[0025] Figure 3 Streamline diagrams at different times of opening the throttle valve;

[0026] Figure 4 Schematic diagram of the flow field of the air film working mode;

[0027] Figure 5 Schematic diagram of the flow field in the blowing working mode.

[0028] Shown in the figure: 1. BCM central control unit; 2. Rearview mirror upper cover; 3. Air duct inner plug; 4. Rearview mirror lower cover; 5. Throttle valve; 6. Rearview lens angle adjustment motor; 7. Rearview mirror lens; 100. Upper surface of the air duct; 200. Lower surface of the air duct. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] Example 1: Large rearview mirror for trucks and large vehicles

[0032] like Figure 1 As shown in the figure, the BCM-based rearview mirror rainwater removal system is controlled by the vehicle's BCM central control unit 1. The system mainly consists of the BCM central control unit 1, the rearview mirror upper cover 2, the air flow channel inner plug 3, the rearview mirror lower cover 4, the blowing direction control throttle valve 5, the rearview mirror angle adjustment motor 6, and the rearview mirror lens 7.

[0033] Inside the rearview mirror body, there is a ventilation channel, and the upper surface 100 and the lower surface 200 of the ventilation channel constitute the inner flow channel of the blowing system. The side of the air channel inner plug 3 is fixed on the left and right side walls of the rearview mirror.

[0034] The upper surface 100 of the airflow channel is characterized by a straight line at its initial stage and an upwardly concave configuration at its exit. The lowest point of the upwardly concave configuration is located near the rotation axis of the rearview lens angle adjustment motor 6. The slope of the curve at the exit of the upwardly concave configuration forms an angle β with the horizontal direction, and the value of β ranges from 30° to 40°.

[0035] The lower surface 200 of the ventilation channel is characterized by a straight line at its beginning and a concave shape at its exit. The curvature of the entire lower surface 200 is less than 0 in the coordinate system, preventing rainwater from stagnating on the lower surface. The lowest point of the concave shape has a slope of 0 and is located at a distance L1 from the rotation axis of the rearview lens angle adjustment motor 6, with a range of 5 to 8 cm.

[0036] The straight line segments of the ventilation channel upper surface 100 and the ventilation channel lower surface 200 at the starting section are parallel line segments, and the angle α between the parallel line segments and the horizontal direction is 30° to 40°.

[0037] The air duct inner plug 3 is located behind the ventilation duct upper surface 100 and the ventilation duct lower surface 200. The total horizontal length of the air duct inner plug 3 is no less than 10 cm. A blow-off direction control throttle valve 5 is located within the air duct inner plug 3. This throttle valve primarily controls the flow of fluid near the ventilation duct lower surface 200. The inner flow channel of the air duct inner plug 3 on one side of the ventilation duct lower surface 200 consists of two parts: one horizontal parallel straight line segment, and the other parallel straight line segment at an angle γ of 45° to the horizontal direction. On one side of the ventilation duct upper surface 100 is a curved or broken line segment, which creates a flow configuration between the air duct inner plug 3 and the ventilation duct upper surface 100 that first contracts and then expands. This flow channel configuration that first contracts and then expands effectively accelerates the airflow passing through the ventilation duct upper surface 100.

[0038] like Figure 2 As shown, the sensor inputs of the BCM central control unit 1 are derived from the vehicle's speed and the rain sensor on the front windshield. The BCM central control unit 1 controls the opening and closing of the blowing direction control throttle valve 5 via control circuitry. When the throttle valve 5 is closed, air flows from the rearview mirror airflow channel inlet through the upper flow channel of the inner plug 3 and out the rearview mirror airflow channel outlet. The outgoing airflow forms an angle β with the horizontal. The thickness of the rear end of the rearview mirror's upper wall is H1, with a value ranging from 3cm to 5cm. The ultimate effect is that when the throttle valve 5 is closed, a barrier airflow is formed at the rear edge of the rearview mirror, preventing raindrops from adhering to the rearview mirror surface.

[0039] When the throttle valve 5 is fully open, air flows from the rearview mirror airflow channel inlet through the upper and lower channels of the inner plug 3 to the rearview mirror airflow channel outlet. Because the lower channel has a concave surface and a relatively low flow rate, the velocity of this portion of airflow at the concave surface is significantly reduced, forming a recirculation zone. This increases the pressure of the airflow at the concave surface, causing the airflow in the upper channel to rise, clinging to the channel wall of the upper surface 100 of the ventilation channel to the upper concave surface of the upper channel. The interaction of the two internal airflows ultimately allows the airflow to exit the rearview mirror outlet at an angle of 70-80°. Due to the high airflow velocity, the Coanda effect causes the airflow to blow away raindrops from the rearview mirror surface as it passes over it. Incorporating the rearview mirror angle adjustment motor 6 allows for more effective adjustment of the raindrop flushing effect.

[0040] The different openings of the throttle valve 5 determine the different exit angles of the airflow. Under different driving speeds and weather conditions, the BCM central control unit 1 adjusts the rearview mirror angle adjustment motor 6 to control the tilt angle of the rearview mirror and the opening of the throttle valve 5 to adjust the blowing effect. Under normal circumstances, the rearview mirror angle remains unchanged. When the rainfall is heavy, it will intermittently deflect to achieve a better blowing effect. The streamline diagram at different times after the throttle valve is opened is shown as follows: Figure 3 shown.

[0041] The system has two working modes:

[0042] The first one, such as Figure 4 As shown, closing the throttle valve allows an air film to form on the outside of the rearview mirror to prevent raindrops from entering.

[0043] The second type, such as Figure 5 As shown, open the throttle valve to blow away the raindrops directly.

[0044] Example 2: Small rearview mirror used in ordinary family cars

[0045] The upper surface 100 of the airflow channel is characterized by a straight line at its initial section and an upwardly concave configuration at its exit. The lowest point of the upwardly concave configuration is located near the rotation axis of the rearview lens angle adjustment motor 6. The slope of the curve at the exit of the upwardly concave configuration forms an angle β with the horizontal direction, and the value of β ranges from 40° to 60°.

[0046] The lower surface 200 of the ventilation channel is characterized by a straight line at its beginning and a concave shape at its exit. The curvature of the entire lower surface 200 is less than 0 in the coordinate system, preventing rainwater from stagnating on the lower surface. The lowest point of the concave shape has a slope of 0 and is located at a distance L1 from the rotation axis of the rearview lens angle adjustment motor 6, with L1 ranging from 7 to 10 cm.

[0047] The straight line segments of the ventilation channel upper surface 100 and the ventilation channel lower surface 200 at the starting section are parallel line segments, and the angle α between the parallel line segments and the horizontal direction is 20° to 30°.

[0048] The BCM central control unit 1 controls the opening and closing of the blowing direction control throttle valve 5 via control circuitry. When the throttle valve 5 is closed, air flows from the rearview mirror airflow channel inlet through the upper flow channel of the inner plug 3 and out the rearview mirror airflow channel outlet. The exiting airflow forms an angle β with the horizontal. The thickness of the rear end of the rearview mirror's upper wall is H1, with a value of H1 ranging from approximately 3 cm. The ultimate effect is that when the throttle valve 5 is closed, a barrier airflow is formed at the rear edge of the rearview mirror, preventing raindrops from adhering to the rearview mirror surface.

[0049] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A rearview mirror rainwater blowing system based on BCM, comprising a BCM central control unit (1), a rearview mirror angle adjustment motor (6), a rearview mirror lens (7), a rearview mirror upper cover (2) and a rearview mirror lower cover (4), characterized in that: An air flow channel inner plug piece (3) is provided between the rearview mirror upper cover (2) and the rearview mirror lower cover (4), and ventilation channels are respectively left between the air flow channel inner plug piece (3) and the rearview mirror upper cover (2) and the rearview mirror lower cover (4), and the side surfaces of the air flow channel inner plug piece (3) are fixed on the left and right side walls of the rearview mirror; a throttle valve (5) is provided inside the air flow channel inner plug piece (3), and the BCM central control unit (1) controls the opening and closing angles of the throttle valve (5) and controls the opening and closing of the ventilation channel at the lower end of the air flow channel inner plug piece (3); The ventilation flow channel is divided into a ventilation flow channel upper surface (100) and a ventilation flow channel lower surface (200); the starting section of the ventilation flow channel upper surface (100) is a straight line section, and the outlet is an upward concave configuration, and the lowest point of the upward concave configuration is located above the rotating shaft of the rearview lens angle adjustment motor (6); the starting section of the ventilation flow channel lower surface (200) is a straight line section, and the outlet is a downward concave configuration; The angle β between the slope of the outlet curve of the upward concave configuration and the horizontal direction is 30° to 60°; the curvature of the lower surface (200) of the air flow channel is less than 0 in the coordinate system, the slope at the lowest point in the downward concave configuration is 0, and the distance from the lowest point of the downward concave configuration to the rotation axis L1 of the rearview lens angle adjustment motor (6) is in the range of 5 to 10 cm.

2. The rearview mirror rain water blowing system based on BCM according to claim 1, characterized in that: The straight line segments of the upper surface (100) of the ventilation flow channel and the lower surface (200) of the ventilation flow channel at the starting section are parallel line segments, and the angle α between the parallel line segments and the horizontal direction is 20° to 40°.

3. The rearview mirror rain water blowing system based on BCM according to claim 1, characterized in that: The air channel inner plug (3) is located at the rear of the straight section of the ventilation channel upper surface (100) and the ventilation channel lower surface (200), dividing the upstream airflow into two parts, the upper airflow being the main airflow and the downstream airflow being the air control flow; on the windward side of the inner plug (3), the inlet area of ​​the upper channel is 4 to 5 times the inlet area of ​​the lower channel, that is, when the throttle valve (5) is opened, the flow rate of the main airflow is 4 to 5 times the flow rate of the air control flow; the total length of the air channel inner plug (3) in the horizontal direction is not less than 10 cm, so as to ensure that the two airflows have different speed characteristics.

4. The rearview mirror rain water blowing system based on BCM according to claim 3, characterized in that: The inner flow channel of the air flow channel inner plug (3) on one side of the ventilation flow channel lower surface (200) is composed of two parts, one part is a horizontal parallel straight line segment, and the other part is a parallel straight line segment with an angle γ of 30° to 50° with the horizontal direction. On one side of the ventilation flow channel upper surface (100) is a curved line segment or a broken line segment, and a flow configuration that first contracts and then expands appears between the air flow channel inner plug (3) and the ventilation flow channel upper surface (100).

5. The rearview mirror rain water blowing system based on BCM according to claim 1, characterized in that: The thickness of the tail portion of the upper wall of the rearview mirror upper cover (2) is H1, and the value range of H1 is not less than 3 cm.

6. The rearview mirror rain water blowing system based on BCM according to claim 1, characterized in that: A rain sensor is installed on the front windshield, and the BCM central control unit (1) receives data from the rain sensor and vehicle speed.

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