Deflector and vehicle having the same
Patent Information
- Application Number
- CN202522105705.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2026-10-30
- Estimated Expiration
- 2035-09-29
AI Technical Summary
[0003]现有车底盘导流板通常为平坦面板,主要用于在车辆行驶过程中防止空气在车辆底盘产生乱流,然而平坦的面板所受气流风阻大,容易受气流冲击而变形
[0016]本实用新型的导流板,包括顶风面板,所述顶风面板为弧形面板,所述弧形面板X向拱起,并且其Y向两侧向后弯曲,将前方气流分流成向上与向下的气流,以及向Y向两侧的气流。向上的气流可以增加车底的抬升力,两侧的气流可以避开导流板后侧的车辆前轮,从而引导前方气流有序流向后侧,防止乱流。而且顶风面板的后侧面设有支撑座以增加顶风面板的结构强度,防止前方气流将顶风面板冲击变形。
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Figure CN224916022U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vehicle body aerodynamic structure, specifically to an aerodynamic deflector and a vehicle having the same. Background Technology
[0002] When a vehicle is traveling at high speed, a large amount of air enters from the front of the car under the chassis. The chassis is usually uneven, which creates turbulence. This turbulence generates significant air resistance. Deflectors are used to block and guide this turbulent air, directing it to flow as far as possible through the sides of the vehicle or through pre-designed channels.
[0003] Existing vehicle chassis deflectors are usually flat panels, mainly used to prevent air turbulence under the vehicle chassis during vehicle operation. However, flat panels are subject to high airflow resistance and are easily deformed by airflow impact. Utility Model Content
[0004] In view of this, the present invention provides a deflector and a vehicle having the same, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.
[0005] To achieve the aforementioned objective, the first aspect of this utility model provides a deflector, including a top wind panel, which is an arc-shaped panel with the middle portion of the arc-shaped panel arched in the X direction. The two sides of the middle portion of the arc-shaped panel are a first side end and a second side end, respectively. The first side end is the side closer to the inside, and the second side end is the side closer to the outside. The first side end and the second side end extend rearward.
[0006] In the aforementioned deflector, optionally, the first side end extends rearward in a straight line, the second side end extends rearward in an arc shape, and the central portion of the arc-shaped panel arches along the X direction near the first side end.
[0007] Optionally, in the aforementioned air deflector, the inner side of the air deflector is provided with a mounting base, and the mounting base is provided with a fixing hole for detachable installation to the front bumper lower guard plate via a fixing connector.
[0008] Optionally, in the aforementioned guide plate, the guide plate is further provided with a positioning pin, which is located on one side of the mounting base and is used for pre-positioning of the guide plate.
[0009] In the aforementioned guide plate, optionally, the outer side of the mounting base is provided with outwardly radially extending connecting ribs, and the positioning pin is provided with a plurality of winglets extending outwardly from the center. The winglets have a top and a bottom, and the width of the top along the radial direction of the positioning pin is smaller than the width of the bottom along the radial direction of the positioning pin.
[0010] Optionally, in the aforementioned deflector, the deflector is provided with a support base, the support base is disposed on the rear side of the top wind panel, and the mounting base and the positioning pin are disposed on the support base.
[0011] In the aforementioned air deflector, optionally, the support base includes a connecting part and a mounting part. A plurality of the connecting parts are arranged along the Y direction of the rear side of the top wind panel. The mounting part is located on the top of the connecting part and is integrated with the connecting part to form a frame structure. The mounting base and the positioning pin are located on the mounting part.
[0012] Optionally, the deflector as described above may also include an air guide panel located below the top air guide panel, extending from the lower end of the top air guide panel and bending to the rear side, and integrally formed with the top air guide panel to form a quarter-spherical shell shape.
[0013] To achieve the aforementioned objective, a second aspect of the present invention provides a vehicle comprising a front bumper lower guard plate and a deflector as described in any one of the preceding first aspects, the deflector being mounted on the bottom of the front bumper lower guard plate.
[0014] In the vehicle described above, optionally, the inner side of the front bumper lower guard plate is provided with a mounting boss, and the mounting boss is provided with positioning holes and mounting holes for cooperating with the positioning pins and mounting seats of the air deflector.
[0015] In the vehicle described above, optionally, the mounting portion protrudes upward, and the locating pin and the mounting seat protrude upward from the top of the deflector and extend into the mounting portion for installation.
[0016] This utility model discloses a deflector, including a top wind panel. The top wind panel is an arc-shaped panel, arched in the X direction and curved backward on both sides in the Y direction, splitting the airflow in front into upward and downward airflows, as well as airflows to the sides in the Y direction. The upward airflow can increase the lifting force under the vehicle, while the airflows on both sides can avoid the front wheels of the vehicle behind the deflector, thereby guiding the airflow in front to flow orderly to the rear and preventing turbulence. Furthermore, a support base is provided on the rear side of the top wind panel to increase its structural strength and prevent the front airflow from impacting and deforming it.
[0017] This utility model also provides a vehicle, including a front bumper lower guard plate and the aforementioned deflector, which has all the features of the aforementioned deflector and therefore also has its corresponding advantages. Attached Figure Description
[0018] The disclosure of this utility model will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.
[0019] Figure 1 This is a side view of an embodiment of the air deflector of this utility model when it is installed on the front bumper lower guard plate.
[0020] Figure 2 for Figure 1 A schematic diagram of the overall structure of an embodiment of the air deflector from one perspective.
[0021] Figure 3 for Figure 1 A schematic diagram of the overall structure from another perspective of an embodiment of the air deflector.
[0022] Figure 4 for Figure 1 A schematic diagram of the overall structure from another perspective of the embodiment of the air deflector.
[0023] Figure 5 for Figure 1 A schematic diagram of the overall structure from another perspective of the embodiment of the air deflector.
[0024] Figure 6 for Figure 1 A partial enlarged view of the embodiment shows the locating pin, mounting base, and support base.
[0025] Figure 7 This is a schematic diagram of the overall structure from one perspective of another embodiment of the guide plate of this utility model.
[0026] Figure 8 for Figure 7 A schematic diagram of the overall structure from another perspective of the embodiment.
[0027] Figure 9 for Figure 7 A schematic diagram of the overall structure from another perspective of the embodiment.
[0028] Figure 10 for Figure 7 A schematic diagram of the overall structure from another perspective of the embodiment.
[0029] Figure 11 for Figure 7 A schematic diagram of the structure of the deflector plate installed on the lower front bumper.
[0030] In the diagram: 1-Front lower guard plate; 11-Mounting boss; 2-Guide plate; 21-Air guide panel; 3-Top wind panel; 31-Support base; 32-Connecting part; 33-Mounting part; 34-Positioning pin; 35-Mounting base; 36-Fixing connector; 37-Fixing hole; 38-Connecting rib; 39-Flange; 41-Top; 42-Bottom; 43-First side end; 44-Second side end. Detailed Implementation
[0031] Referring to the accompanying drawings and specific embodiments, the structure, composition, features and advantages of the air deflector of this utility model and the vehicle having it will be described by way of example below. However, all descriptions should not be used to limit the utility model in any way.
[0032] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various drawings, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle. Therefore, these further embodiments according to the present invention should also be considered within the scope of the description herein.
[0033] It should also be noted that the terms "front", "rear", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship of the deflector and the vehicle having it shown in the accompanying drawings. They are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.
[0034] In the description of this disclosure, "multiple" means at least two, such as two, three or more, unless otherwise expressly and specifically limited.
[0035] like Figure 1 In the coordinate system shown, the X, Y, and Z directions are based on the vehicle coordinate system, which is a special moving coordinate system used to describe the motion of a vehicle. The origin of this coordinate system coincides with the center of mass of the vehicle. When the vehicle is stationary on a horizontal road, the X direction of this coordinate system refers to the direction parallel to the direction of the vehicle's travel, with the direction of the vehicle's travel being forward and the opposite being backward. The Y direction refers to the width direction of the vehicle, and the Z direction refers to the height direction of the vehicle.
[0036] like Figure 1 As shown, the air deflector 2 of this utility model is installed at the rear bottom of the front bumper lower guard plate 1 of the vehicle, and is located in front of the front wheel (not shown in the figure). The front bumper lower guard plate 1 is part of the vehicle bottom, and the air deflector 2 is installed at the bottom of the front bumper lower guard plate 1, that is, installed at the bottom of the vehicle. It should be noted here that... Figure 1 Only the guide vane 2 on the Y-direction side of the front bumper lower guard plate 1 is shown. In actual applications, guide vanes 2 are provided on both Y-direction sides of the front bumper lower guard plate 1, such as... Figure 1 The arrows from right to left in the diagram represent the airflow generated in front of the vehicle during its movement. The deflector 2 is used to guide the direction of the airflow in front to reduce wind resistance.
[0037] Combination Figures 2 to 5As can be seen, the deflector 2 of this utility model includes a top wind panel 3, which is an arc-shaped panel. The middle part of the arc-shaped panel arches forward along the X direction, and the parts on both sides of the middle part bend backward to guide the airflow in front to the sides of the top wind panel 3, and guide the airflow between the wheel and the deflector 2, without blowing directly on the wheel, thus avoiding raising dust during driving.
[0038] Combination Figure 1 and Figure 4 As can be seen, the top wind panel 3 is an irregular arc-shaped panel, that is, the curvature of each part of the arc-shaped panel is different. The two sides of the arc-shaped panel are the first side end 43 and the second side end 44, respectively. The first side end 43 is the side closer to the interior of the vehicle and extends backward in an approximately straight line. The second side end 44 is the side closer to the exterior of the vehicle and extends backward in an arc. The part of the middle of the arc-shaped panel that arches forward along the X direction is close to the second side end 44, so that the Y-direction length of the arc surface in the middle of the first side end 43 is greater than the Y-direction length of the arc surface in the middle of the second side end 44.
[0039] In other embodiments, the top wind panel 3 can also be a circular arc panel, an elliptical arc panel, or an irregular arc panel with other curvatures, which can be set according to actual needs.
[0040] Figure 1 , Figure 2 The arrows from right to left indicate the airflow ahead. The top wind panel 3 faces the airflow ahead and splits it, with some airflow such as... Figure 1 , Figure 2 The downward-pointing arrows flow downwards along the top wind panel 3 to reduce wind resistance during vehicle movement; a portion of the airflow, such as... Figure 1 , Figure 2 The upward arrow, pointing upwards along the roof panel 3, provides an upward lifting force to the front bumper lower guard plate 1. It should be noted that the front bumper lower guard plate 1 is located at the bottom of the vehicle, and providing a lifting force to the front bumper lower guard plate 1 means providing a lifting force to the vehicle from the bottom, making the vehicle lighter during driving.
[0041] Furthermore, such as Figure 1 , Figure 2 As shown, the top wind panel 3 can be tilted backward, allowing the airflow in front to flow smoothly downward along the tilted surface. More specifically, the Z-direction cross-section of the top wind panel 3 is a slightly curved curve tilted backward, which allows the airflow to flow more smoothly.
[0042] The airflow passing in front of the top wind panel 3 is also guided and diverted to both sides of the top wind panel 3 in the Y direction, specifically, as follows: Figure 3The upward arrow indicates the airflow ahead. The top wind panel 3 faces the airflow ahead and diverts it, directing it to flow backward and to both sides along the Y-axis of the top wind panel 3. In other words, the top wind panel 3 guides the airflow ahead to flow regularly to the sides and up and down, reducing wind resistance and increasing lift. Combined with... Figure 4 It can be seen that the Y-direction length of the arc-shaped surface in the middle of the top wind panel 3 near the first side end 43 is longer, thereby guiding more airflow in front to the bottom of the vehicle. That is, guiding the airflow in front to flow backward along the straight line shape of the first side end 43 at the bottom of the vehicle, thereby driving the airflow direction of the vehicle chassis and preventing turbulence from occurring under the vehicle.
[0043] To facilitate the installation of the air deflector 2 on the front bumper lower guard plate 1, such as Figure 2 , Figure 3 as well as Figure 5 The deflector 2 is also provided with a mounting base 35, which is located on the rear side of the top wind panel 3, and as shown in the figure. Figure 3 and Figure 6 As shown, the mounting base 35 has a fixing hole 37, which is used in conjunction with... Figure 11 As shown, the fixing hole 37 is used to install the fixing connector 36; Fixed connector 36 can be as follows Figure 11 The stud shown in the embodiment engages with the fixing hole 37, allowing the mounting base 35 to be detachably installed on the front bumper lower guard plate 1. In other embodiments, the fixing connector 36 may include, but is not limited to, bolts, clips, or other easily detachable fixing components, allowing the guide plate 2 to be detachably installed on the front bumper lower guard plate 1 through the engagement of the fixing connector 36 and the mounting base 35.
[0044] Furthermore, such as Figure 2 and Figure 3 The guide plate 2 is also equipped with a positioning pin 34, combined with Figure 11 Positioning pin 34 is used to pre-position the lower front bumper guard 1. For example... Figure 2 and Figure 3 As shown, the positioning pin 34 and the mounting base 35 are integrally formed, so that while the positioning pin 34 is positioned and installed on the front lower guard plate 1, the fixing hole 37 of the mounting base 35 is also aligned with the mounting part of the front lower guard plate 1. This facilitates the fastening connector 36 to pass through the mounting part of the front lower guard plate 1 and extend into the fixing hole 37. Moreover, the integral formation of the positioning pin 34 and the mounting base 35 increases the strength of both. It can be understood that the above-mentioned effect can also be achieved if the positioning pin 34 and the mounting base 35 are set separately.
[0045] Combination Figure 6As shown, the mounting base 35 is columnar, with connecting ribs 38 extending radially outward from its outer side. The connecting ribs 38 enable the mounting base 35 to have high strength while maintaining a light weight. The locating pin 34 is provided with several fins 39 extending radially outward from the center. This structural design enables the locating pin 34 to have high strength while maintaining a light weight.
[0046] Each wing 39 of the positioning pin 34 is divided into a top 41 and a bottom 42. The width of the top 41 along the radial direction of the positioning pin 34 is smaller than the width of the bottom 42 along the radial direction of the positioning pin 34. The top 41 is used for positioning with the front lower guard plate 1, and a part of the bottom 42 is connected to the connecting rib 38, which further enhances the strength of the mounting base 35 and the positioning pin 34.
[0047] Combination Figure 3 and Figure 5 It can be seen that the top wind panel 3 is relatively long in the Y direction. In order to better position the top wind panel 3 on the front bumper lower guard plate 1, multiple positioning pins 34 can be set on the top wind panel 3 to better position the top wind panel 3 on the front bumper lower guard plate 1.
[0048] like Figure 5 In this embodiment, the deflector 2 is provided with two positioning pins 34, which are located near the corner of the top wind panel 3. It is understood that the corner, due to its curvature, makes it difficult to fit snugly against the front lower guard plate 1 during installation. Therefore, positioning the pins 34 and mounting bases 35 at the corner allows for better positioning and ensures that the top of the top wind panel 3 fits more closely against the front lower guard plate 1, thus securing it more firmly. It is understood that the closer the top of the top wind panel 3 fits against the front lower guard plate 1, the smaller the gap between the top wind panel 3 and the front lower guard plate 1, preventing airflow from passing through the gap and disrupting the fixed connection between the top wind panel 3 and the front lower guard plate 1.
[0049] To reinforce the top wind panel 3, combined with Figure 5 and Figure 6 It can be seen that the deflector plate 2 is also provided with a support base 31. The support base 31 is located on the rear side of the top wind panel 3, which is used to increase the structural strength of the top wind panel 3 and its installation connection parts, and to prevent the top wind panel 3 from deforming due to the impact of the airflow in front.
[0050] Specifically, such as Figure 6 As shown, the support base 31 includes a connecting part 32 and a mounting part 33. Multiple connecting parts 32 are arranged along the Y direction of the rear side of the top wind panel 3 and protrude rearward from the rear side of the top wind panel 3. The mounting part 33 is located on the top of the connecting part 32 and is integrated with the connecting part 32 to form a frame structure. This frame structure is integrated with the top wind panel 3, which can further increase the strength of the top wind panel 3.
[0051] exist Figure 6 In this embodiment, the positioning pin 34 and the mounting base 35 are disposed on the mounting part 33. With the support of the mounting part 33 and the connecting part 32, a stable connection between the positioning pin 34 and the mounting base 35 and the top wind panel 3 can be achieved.
[0052] Combination Figure 1 and Figure 6 It can be seen that the mounting part 33 provides support for the positioning pin 34 and the mounting base 35, so that the positioning pin 34 and the mounting base 35 can be connected to the front lower guard plate 1 along the Z direction, reducing the difficulty of the connection operation. During installation, only the up and down direction insertion and connection action is required to realize the connection between the guide plate 2 and the front lower guard plate 1, and make the installation of the guide plate 2 and the front lower guard plate 1 more stable.
[0053] In order to better guide the airflow ahead, combined with Figures 7 to 10 As shown, an air guide panel 21 is added below the top wind panel 3. The air guide panel 21 extends from the lower end of the top wind panel 3 and bends to the rear side, so that the air guide plate forms a quarter-spherical shell shape. The air guide panel 21 is integrally formed with the top wind panel 3 and is used to guide the airflow in front to the bottom.
[0054] Specifically, with Figure 7 The arrows from right to left in the diagram indicate the airflow ahead. As can be seen from the diagram, the top wind panel 3 guides the airflow upwards and downwards. The guide panel 21 extends the top wind panel 3 downwards to guide the downward-flowing airflow after it has been diverted from the top wind panel 3. Figure 7 The downward-curving arrows flow downwards and backwards along the air guide panel 21, thereby increasing the guiding distance of the downward-flowing airflow. The airflow flowing backwards along the air guide panel 21 can reduce the impact of the frontal airflow (such as...) on the top wind panel 3. Figure 7 The air guide panel 21 reduces the impact of the airflow from right to left on the top wind panel 3, thereby reducing the damage caused by the airflow from the front. Furthermore, the streamlined structure formed by the air guide panel 21 and the top wind panel 3 guides the airflow to the rear, which can also reduce wind resistance at the front and help increase vehicle speed.
[0055] from Figure 11 It can be seen that the air deflector 2 is installed at the bottom of the front bumper lower guard plate 1. Figure 1 and Figure 11 The air deflector 2 in this embodiment is installed in the same way as the front bumper lower guard plate 1. The following will refer to... Figure 11 The following is an example of an embodiment.
[0056] like Figure 11 As shown, the inner side of the front bumper lower guard plate 1 is provided with a mounting boss 11, which has positioning holes and mounting holes (not shown in the figure) for installation with the air deflector 2. Specifically, in conjunction with Figure 10 The illustrated embodiment, in Figure 10 In the embodiment shown, the positioning pin 34 and the mounting base 35 of the guide plate 2 protrude upward from the top of the guide plate 2.
[0057] During installation, the positioning pin 34 of the air deflector 2 and the mounting base 35 extend upward into the interior of the front bumper lower guard plate 1 to achieve accurate positioning and secure installation of the air deflector 2 and the front bumper lower guard plate 1. Specifically, the positioning pin 34 passes through the positioning hole of the mounting boss 11 for positioning, thereby aligning the fixing hole 37 on the mounting base 35 with the mounting hole of the mounting boss 11. Then, the fixing connector 36 passes through the mounting hole and is fixed in the fixing hole 37 to complete the positioning and installation of the air deflector 2 and the front bumper lower guard plate 1.
[0058] During disassembly, the fixing connector 36 is removed from the fixing holes of the mounting base 35 and the mounting boss 11, and the guide plate 2 can be removed from the front lower guard plate 1. It can be seen that the positioning pin 34 and the mounting base 35 of the guide plate 2 of this utility model can facilitate the installation or disassembly of the guide plate 2.
[0059] This utility model also provides a vehicle, including a front bumper lower guard plate 1 and the aforementioned deflector plate 2. The front bumper lower guard plate 1 is provided with a mounting boss 11, and the deflector plate 2 is installed at the bottom of the front bumper lower guard plate 1.
[0060] The air deflector 2 of this utility model includes a top wind panel 3 and an air guide panel 21. The air guide panel 21 is located below the top wind panel 3. The air guide panel 21 is an arc-shaped panel that arches in the X direction on both sides of the middle. The air guide panel 21 extends downward from the bottom of the top wind panel 3 and bends to the rear end, forming a quarter-sphere shape with the top wind panel 3.
[0061] The airflow generated by the vehicle's movement is split into upward and downward airflows, as well as airflows to the Y-direction on both sides, by the spherical deflector 2. The upward airflow can increase the lifting force under the vehicle, and the airflows on both sides can avoid the front wheels of the vehicle behind the deflector 2, thereby guiding the orderly flow of the forward airflow to the rear and preventing turbulence.
[0062] The rear side of the top wind panel 3 of the guide plate 2 of this utility model is provided with a support base 31, a mounting base 35 and a positioning pin 34. The mounting base 35 and the positioning pin 34 are integrally set with the support base 31, which increases the structural strength of the top wind panel 3 and facilitates the installation of the guide plate 2 on the front lower guard plate 1.
[0063] This utility model also provides a vehicle, including a front bumper lower guard plate 1 and the aforementioned deflector plate 2, which has all the features of the aforementioned deflector plate 2, and therefore also has its corresponding advantages.
[0064] The technical scope of this utility model is not limited to the contents of the above description. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the scope of this utility model.
Claims
1. A deflector plate, characterized in that, Includes a top wind panel (3), which is an arc-shaped panel. The middle part of the arc-shaped panel is arched in the X direction. The two sides of the middle part of the arc-shaped panel are a first side end (43) and a second side end (44), respectively. The first side end (43) is the side closer to the inside, and the second side end (44) is the side closer to the outside. The first side end (43) and the second side end (44) extend backward.
2. The guide plate as described in claim 1, characterized in that, The first side end (43) extends rearward in a straight line, and the second side end (44) extends rearward in an arc shape. The middle part of the arc-shaped panel arches along the X direction near the first side end (43).
3. The guide plate as described in claim 1, characterized in that, The inner side of the guide plate (2) is provided with a mounting base (35), and the mounting base (35) is provided with a fixing hole (37) for being detachably installed to the front lower guard plate (1) through a fixing connector (36).
4. The guide plate as described in claim 3, characterized in that, The guide plate (2) is also provided with a positioning pin (34), which is located on one side of the mounting base (35) and is used for pre-positioning of the guide plate (2).
5. The guide plate as described in claim 4, characterized in that, The mounting base (35) has outwardly radially extending connecting ribs (38) on its outer side, and the positioning pin (34) has a plurality of radially extending winglets (39) from the center outward. The winglets (39) have a top (41) and a bottom (42). The width of the top (41) along the radial direction of the positioning pin (34) is smaller than the width of the bottom (42) along the radial direction of the positioning pin (34).
6. The guide plate as described in claim 4, characterized in that, The guide plate (2) is provided with a support base (31), which is located on the rear side of the top wind panel (3). The mounting base (35) and the positioning pin (34) are located on the support base (31).
7. The guide vane as described in claim 6, characterized in that, The support base (31) includes a connecting part (32) and a mounting part (33). Multiple connecting parts (32) are arranged along the Y direction of the rear side of the top wind panel (3). The mounting part (33) is located on the top of the connecting part (32) and is integrated with the connecting part (32) to form a frame structure. The mounting base (35) and the positioning pin (34) are located on the mounting part (33).
8. The guide vane as described in claim 1, characterized in that, It also includes an air guide panel (21), which is located below the top air panel (3) and extends from the lower end of the top air panel (3) and bends to the rear side, forming a quarter-spherical shell shape integrally with the top air panel (3).
9. A vehicle, characterized in that, The vehicle includes a front bumper underbody protection plate (1) and a deflector plate (2) as described in any one of claims 1-8, the deflector plate (2) being mounted on the bottom of the front bumper underbody protection plate (1).
10. The vehicle as claimed in claim 9, characterized in that, The inner side of the front lower guard plate (1) is provided with a mounting boss (11), and the mounting boss (11) is provided with a positioning hole and a mounting hole for cooperating with the positioning pin (34) and mounting seat (35) of the guide plate (2).