Vehicle undercarriage

Abstract

The objective is to provide a vehicle undercarriage structure that can prevent damage to the underbody cover due to road surface interference. [Solution] The vehicle understructure includes an under cover 4 that covers the bottom surface of the vehicle body 1 in front of a pair of front wheels 2 and in the area between the pair of front wheels 2. The under cover 4 has a movable panel 11 that is movable in the vertical direction, a fixed frame 12 positioned above the movable panel 11 and fixed to the bottom surface of the vehicle body 1, and a deformable member 13 that connects at least the front end 11c of the movable panel 11 to the fixed frame 12. The deformable member 13 is made of a material softer than the movable panel 11 and is configured to deform when the movable panel 11 comes into contact with the road surface, thereby enabling the movable panel 11 to move upward.

Description

Technical Field

[0001] The present invention relates to a vehicle lower structure.

Background Art

[0002] Conventionally, various vehicle lower structures provided with a member such as an undercover on the lower side of the front portion of the vehicle body have been proposed in order to control the airflow flowing under the vehicle body during vehicle travel.

[0003] For example, Patent Document 1 discloses a vehicle provided with an undercover that descends when the vehicle travels at high speed. In this vehicle, the negative pressure at the bottom of the vehicle body is increased by the bottom surface of the undercover that descends during high-speed travel, thereby improving the adhesion of the vehicle body to the road surface and enhancing stability during high-speed travel.

[0004] Further, Patent Document 2 discloses a vehicle provided with a movable tire cover that descends in front of a tire when the vehicle travels at high speed. This movable tire cover prevents wind from hitting the tire during high-speed travel.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0006] In both of the above two structures, when the vehicle is traveling with a member such as the undercover on the lower front portion of the vehicle body lowered to a position near the road surface, if an obstacle such as a block protruding from the road surface or a large step is encountered, the undercover may interfere with the obstacle or the step. In that case, the undercover may be damaged due to interference with the obstacle or step on the road surface.

[0007] This invention has been made in view of the circumstances described above, and aims to provide a vehicle undercarriage structure that can prevent damage to the underbody cover due to road surface interference. [Means for solving the problem]

[0008] To solve the aforementioned problems, the vehicle understructure of the present invention comprises an under cover that covers the bottom surface of the vehicle body in front of a pair of front wheels and in the area between the pair of front wheels, wherein the under cover comprises a movable panel that is movable in the vertical direction, a fixed frame positioned above the movable panel and fixed to the bottom surface of the vehicle body, and a deformable member that connects at least the front end of the movable panel to the fixed frame, wherein the deformable member is made of a material softer than the movable panel and is configured to deform when the movable panel comes into contact with the road surface, thereby enabling upward movement of the movable panel.

[0009] According to this configuration, the underbody cover includes a movable panel, a fixed frame fixed to the underside of the vehicle body, and a deformable, flexible member connecting at least the front end of the movable panel to the fixed frame. Therefore, when the movable panel of the underbody cover comes into contact with an obstacle or step protruding from the road surface while the vehicle is in motion, i.e., when the movable panel interferes with the road surface, the flexible member deforms and moves upward to reduce the load on the movable panel. This makes it possible to prevent damage to the underbody cover when it interferes with the road surface.

[0010] In the above-described undercarriage structure of the vehicle, it is preferable that the movable panel is made of polypropylene and the deformable member is made of elastomer.

[0011] With this configuration, the deformable member is made of elastomer, making it significantly softer and more deformable than a movable panel made of polypropylene. Therefore, when the movable panel comes into contact with the road surface, the deformable member deforms significantly with a small load, enabling rapid and smooth upward movement of the movable panel. As a result, it becomes possible to reliably prevent damage to the under cover when it comes into contact with the road surface.

[0012] In the vehicle understructure described above, it is preferable that the deformation member is arranged along the entire front end of the movable panel and the side ends on both sides in the vehicle width direction, excluding the rear end, and that the rear end of the movable panel is fixed to the fixed frame.

[0013] In this configuration, the front end and the rear ends of both sides of the movable panel are connected to the fixed frame via a deformation member, and the rear end of the movable panel is partially fixed to the fixed frame. Therefore, since the movable panel is supported by the fixed frame in a cantilevered manner only at its rear end, the front end of the movable panel can swing significantly in the vertical direction when it comes into contact with the road surface. As a result, it becomes possible to reliably prevent damage to the underbody cover when it comes into contact with the road surface.

[0014] In the above-described underbody structure of the vehicle, it is preferable that the length of the longitudinal cross-section of the deformable member at the front of the under cover is greater than the length of the vehicle width cross-section of the deformable member at the side of the under cover.

[0015] With this configuration, the vertical swing range of the front end of the movable panel is increased, making it possible to more reliably prevent damage to the underbody cover when it comes into contact with the road surface.

[0016] In the above-described vehicle understructure, it is preferable that the deformation member extends between the front end of the movable panel and the fixed frame to a length such that when the front end of the movable panel moves upward, the deformation member is less than or equal to the height of the front end of the deformation member.

[0017] According to such a configuration, the deformable member extends for the aforementioned length between the front end portion of the movable panel and the fixed frame, so that when the front end portion of the movable panel moves upward during interference with a road surface, the height of the front end portion of the movable panel does not exceed the height of the front end portion of the deformable member. This eliminates the risk that the front end portion of the movable panel moves above the front end portion of the deformable member and pulls the deformable member, causing damage thereto. Effects of the Invention

[0018] As described above, according to the vehicle lower structure of the present invention, damage to the undercover due to road surface interference can be prevented. Brief Description of the Drawings

[0019] [Figure 1] This is a perspective view of the undercover and its peripheral part showing the main part of the vehicle lower structure according to the embodiment of the present invention, as viewed from the diagonally front-left lower side. [Figure 2] This is an enlarged perspective view of the undercover of Fig. 1, as viewed from the diagonally front-right lower side. [Figure 3] This is a bottom view of the left portion of the undercover of Fig. 1. [Figure 4] This is a side view of the front portion of the left side surface of the undercover of Fig. 1. [Figure 5] This is a front view of the front left half of the vehicle body of Fig. 1. [Figure 6] This is a sectional view taken along line VI-VI of Fig. 5. [Figure 7] This is a perspective view of the right half of the undercover of Fig. 1, as viewed from the diagonally lower-right side. [Figure 8] This is a sectional view taken along line VIII-VIII of Fig. 7. [Figure 9] This is a sectional view taken along line IX-IX of Fig. 7. Modes for Carrying Out the Invention

[0020] Hereinafter, the vehicle lower structure according to the embodiment of the present invention will be described in detail with reference to the drawings.

[0021] Figure 1 discloses a vehicle understructure equipped with an under cover 4 as an embodiment of the vehicle understructure of the present invention.

[0022] Specifically, the vehicle understructure shown in Figure 1 includes an under cover 4 that is movable in the vertical direction Z and covers the bottom surface of the vehicle body 1 in the area between the pair of front wheels 2, in front of the pair of front wheels 2 by X1. As shown in Figures 1 and 5-6, the under cover 4 is positioned on the bottom surface of the vehicle body 1 in the area from near the front end of the bumper 3 to the front end of the front wheels 2.

[0023] Furthermore, in the vehicle understructure of this embodiment, as shown in Figure 1, a floor panel 5 covering the bottom surface of the vehicle body 1 is positioned X2 to the rear of the vehicle from the under cover 4. In addition, a pair of side under covers 6 are positioned on both sides of the under cover 4 in the vehicle width direction Y. Note that these floor panels 5 and side under covers 6 are not essential components in this invention and may be replaced with other members.

[0024] The following provides a more detailed explanation of the specific structure of Undercover 4.

[0025] As shown in Figures 2-9, the under cover 4 includes a movable panel 11 that is movable in the vertical direction Z, a fixed frame 12 positioned above the movable panel 11 and fixed to the bottom surface of the vehicle body 1, and a deformable member 13 that connects at least the front end 11c of the movable panel 11 (in this embodiment, the area A excluding the rear end 11d at both side ends 11e (see Figure 7)) and the fixed frame 12.

[0026] As shown in Figures 6-7, the movable panel 11 has a flat bottom surface 11a and a forward sloped surface 11b that slopes upward from the front end of the bottom surface 11a toward the front side X1 of the vehicle. The front end 11c and the side ends 11e on both sides in the vehicle width direction Y, excluding the rear end 11d, are spaced apart from the fixed frame 12 (see Figure 7). On the other hand, the rear end 11d of the movable panel 11 is fixed to the fixed frame 12 (specifically, the rear fixing part 12d). Therefore, the movable panel 11 is partially supported by the fixed frame 12 at the rear end 11d in a cantilevered state.

[0027] The fixed frame 12 is a frame fixed to the bottom surface of the vehicle body 1, as shown in Figures 6-7. The fixed frame 12 has a front portion 12a, a pair of side portions 12b extending rearward X2 from both ends of the front portion 12a in the vehicle width direction Y, a front fixing portion 12c fixed to the bottom surface of the bumper 3 of the vehicle body 1, and a rear fixing portion 12d fixed to the suspension cross member 20 of the vehicle body 1 (a cross member extending in the vehicle width direction Y, located rearward X2 from the bumper 3). The front portion 12a is inclined upward as it moves forward X1, at the same inclination angle as the front sloping portion 11b described above.

[0028] The movable panel 11 and the fixed frame 12 are manufactured from deformation-resistant resin or metal materials. For example, the movable panel 11 and the fixed frame 12 are made from deformation-resistant resin materials such as polypropylene. The movable panel 11 has sufficient bending rigidity to swing by elastic deformation in the vertical Z direction.

[0029] The deformable member 13 is made of a material softer than the movable panel 11, and is made of a resin material that is more easily deformed than polypropylene, such as an elastomer. As shown in Figure 6, the deformable member 13 is configured to deform when the movable panel 11 comes into contact with the road surface, thereby enabling the movable panel 11 to move upward.

[0030] Specifically, the deformable member 13 is made of a deformable elastomer film. The deformable member 13 is positioned along the entire front end 11c of the movable panel 11 (the entire length in the vehicle width direction Y) and along the range A of the side ends 11e on both sides in the vehicle width direction Y, excluding the rear end 11d.

[0031] More specifically, at the front portion 4a of the under cover 4, as shown in Figures 6-7 and 9, the front end portion 13b of the deformation member 13 is joined to the rear end portion 12a1 of the front portion 12a of the fixed frame 12. The rear end portion 13c of the deformation member 13 is joined to the front end portion 11c of the movable panel 11. It is preferable that the front end portion 11c of the movable panel 11 be flat, as this facilitates the joining of the deformation member 13, which is made of elastomer. The joining point P2 between the rear end portion 13c of the deformation member 13 and the front end portion 11c of the movable panel 11, as shown in Figure 9, is positioned slightly above (about 5 mm above) the front sloping portion 11b of the movable panel 11. Therefore, there is no risk of the joining point P2 interfering with the road surface (or the slope S described later), and the front sloping portion 11b will interfere with the road surface before the joining point P2.

[0032] Furthermore, on the side portion 4b of the under cover 4, as shown in Figures 7-8, the outer end 13d of the deformation member 13 in the vehicle width direction Y1 is joined to the lower end 12b1 of the side portion 12b of the fixed frame 12. The inner end 13e of the deformation member 13 in the vehicle width direction Y2 is joined to the side end 11e of the movable panel 11. The joint point P1 between the end 13e of the deformation member 13 and the side end 11e of the movable panel 11, as shown in Figure 8, is positioned slightly above (about 5 mm above) the bottom surface 11a of the movable panel 11. Therefore, there is no risk of the joint point P1 interfering with the road surface (or the slope S described later), and the bottom surface 11a will interfere with the road surface before the joint point P1.

[0033] Furthermore, it is preferable that the front end 11c and side end 11e of the movable panel 11 are flat, as this facilitates the joining of the deformable member 13 made of different materials such as elastomer.

[0034] As shown in Figures 8-9 above, the deformable member 13 is connected to the movable panel 11 and the fixed frame 12 with a length that allows for some slack, so it does not obstruct the movement of the movable panel 11 in the vertical Z direction.

[0035] Next, the arrangement and dimensions of the under cover 4 will be explained with reference to Figure 6. Here, the normal road surface is defined as the normal driving surface RBL of the vehicle, and the road surface interference line RCL, which is at a predetermined height HC from the driving surface RBL, is defined as the height of obstacles and steps on the road surface.

[0036] The height HC of the road surface interference line (RCL) is set considering the type of vehicle (such as a regular passenger car or SUV) and the expected driving environment, and is set to approximately 100-130 mm, for example.

[0037] With respect to the running surface RBL, the height HB of the bottom portion 11a of the movable panel 11 is set to a height that does not come into contact with the running surface RBL during normal driving, and is lower than the height HC of the road surface interference line RCL. This height HB is preferably a height at which the negative pressure decreases on the rear side X2 of the bottom portion 11a when the vehicle is in motion.

[0038] Furthermore, the height HD of the front end portion 11c of the movable panel 11 is preferably as high as possible (so that the deformable member 13 does not interfere with the road surface) and it is preferable that only the movable panel 11 does not interfere with the road surface, and if possible, it is better that it is greater than the height HC of the road surface interference line RCL.

[0039] Furthermore, the inclination angle θ of the front portion 4a of the under cover 4 (specifically, the forward sloping portion 11b of the movable panel 11 and the front portion 12a of the fixed frame 12) with respect to the running surface RBL is set to be greater than the angle of an inclined surface expected in usage conditions in which the vehicle may be driven under normal operating conditions, such as a slope S expected when driving on a typical inclined road or when driving off-road (i.e., an inclined surface that assumes a scenario in which the vehicle rapidly goes up and down a bank along the line connecting the contact point of the front wheels 2 and the front end of the bumper 3 when driving off-road).

[0040] Furthermore, in the front portion 4a of the under cover 4, it is preferable that the deformation member 13 is set so as to have a smaller width H2 in the direction Z shown in Figure 9 and a larger width W2 in the front-rear direction X, so as not to interfere with the slope S.

[0041] In order to increase the range of swing in the vertical Z direction of the movable panel 11, which is supported in a cantilevered manner on the fixed frame 12 as described above, it is preferable that the length of the front-rear cross-section of the deformable member 13 on the front portion 4a of the under cover 4 (i.e., the total length of the portion that extends curved from the front end 13b to the rear end 13c) is greater than the length of the cross-section of the deformable member 13 on the side portion 4b of the under cover 4 (i.e., the total length of the portion that extends curved from the outer end 13d in the vehicle width direction to the inner end 13e in the vehicle width direction), as shown in Figures 8-9.

[0042] Furthermore, as shown in Figures 6 and 9, the deformation member 13 is located between the front end 11c of the movable panel 11 and the fixed frame 12. If the deformation member 13 goes above the front end 13b of the deformation member 13 when the front end 11c of the movable panel 11 moves upward, it may pull on the deformation member 13 and cause damage. Therefore, to avoid damage, it is preferable that the deformation member 13 extends to a length such that when the front end 11c of the movable panel 11 moves upward, it is below the height of the front end 13b of the deformation member 13. Accordingly, it is preferable that the horizontal length W2 (length in the front-rear direction X) of the deformation member 13 at the front portion 4a of the under cover 4 shown in Figure 9 is sufficiently longer than the horizontal length W1 (length in the vehicle width direction Y) of the deformation member 13 at the side portion 4b of the under cover 4 shown in Figure 8.

[0043] As described above, when the movable panel 11 and the fixed frame 12 are made of a resin material such as polypropylene, and the deformable member 13 is made of a film of a resin material such as elastomer, the under cover 4 can be integrally formed by two-color molding using two types of resin materials, polypropylene and elastomer.

[0044] Since the deformable member 13 is made of a membrane, it connects the movable panel 11 and the fixed frame 12, and also seals the gap between the movable panel 11 and the fixed frame 12, preventing air and water from entering the inside of the under cover 4.

[0045] Furthermore, in this embodiment, as shown in Figures 2-4 and 7, the deformable member 13, which is made of a membrane, has recesses 14 at both ends in the vehicle width direction Y of the front portion 4a of the under cover 4, so as to be the starting points for the deformation of the deformable member 13.

[0046] (Features of this embodiment) (1) As shown in Figures 1 to 9, the undercarriage of the vehicle in this embodiment includes an under cover 4 that covers the bottom surface of the vehicle body 1 in front of a pair of front wheels 2 and in the area between the pair of front wheels 2. The under cover 4 has a movable panel 11 that is movable in the vertical direction Z, a fixed frame 12 positioned above the movable panel 11 and fixed to the bottom surface of the vehicle body 1, and a deformable member 13 that connects at least the front end 11c of the movable panel 11 to the fixed frame 12. The deformable member 13 is made of a material softer than the movable panel 11 and is configured to deform when the movable panel 11 comes into contact with the road surface, thereby enabling the movable panel 11 to move upward.

[0047] According to this configuration, the under cover 4 has a movable panel 11, a fixed frame 12 fixed to the bottom surface of the vehicle body 1, and a deformable, flexible deformable member 13 connecting at least the front end 11c of the movable panel 11 to the fixed frame 12. Therefore, as shown in Figure 6, when the movable panel 11 of the under cover 4 comes into contact with an obstacle or step protruding from the road surface while the vehicle is in motion, that is, when the movable panel 11 interferes with the road surface, the flexible deformable member 13 deforms and moves upward to the movable panel 11, thereby reducing the load on the movable panel 11. This makes it possible to prevent damage to the under cover 4 when it interferes with the road surface.

[0048] Furthermore, with the above configuration, there is no risk of damage to the movable panel 11, making it possible to position the flat bottom surface 11a of the movable panel 11 at a height close to the road surface. As a result, when the vehicle is in motion, the negative pressure on the flat bottom surface 11a of the movable panel 11 decreases from the front end towards the rear, allowing air to flow more easily, and the pair of front wheels 2 located on both sides of the movable panel 11 in the vehicle width direction are less likely to be hit by the airflow. Consequently, it becomes possible to reduce air resistance during driving.

[0049] Furthermore, in order to improve the effect of reducing air resistance, it is preferable that the length of the movable panel 11 in the front-rear direction X, especially the length of the bottom surface 11a, be long. For this reason, it is preferable that the position of the front end 11c of the movable panel 11 be as far forward as possible.

[0050] (2) In the vehicle understructure of this embodiment, the movable panel 11 is made of polypropylene. The deformable member 13 is made of elastomer.

[0051] With this configuration, the deformable member 13 is made of elastomer, making it significantly softer and more deformable than the movable panel 11 made of polypropylene. Therefore, when the movable panel 11 comes into contact with the road surface, the deformable member 13 deforms significantly with a small load, enabling the movable panel 11 to move quickly and smoothly upward. As a result, it becomes possible to reliably prevent damage to the under cover 4 when it comes into contact with the road surface.

[0052] (3) In the vehicle understructure of this embodiment, as shown in Figures 6-7, the deformation member 13 is arranged along the entire front end 11c of the movable panel 11 and along the range A of the side ends 11e on both sides in the vehicle width direction, excluding the rear end 11d. The rear end 11d of the movable panel 11 is fixed to the fixed frame 12.

[0053] With this configuration, the area A of the movable panel 11, excluding the front end 11c and both side ends 11e and the rear end 11d, is connected to the fixed frame 12 via the deformation member 13, and the rear end 11d of the movable panel 11 is partially fixed to the fixed frame 12. Therefore, since the movable panel 11 is supported by the fixed frame 12 in a cantilevered manner only at the rear end 11d, the front end 11c of the movable panel 11 can swing significantly in the vertical direction Z when it comes into contact with the road surface. As a result, it becomes possible to reliably prevent damage to the under cover 4 when it comes into contact with the road surface.

[0054] In this embodiment, the movable panel 11, supported in a cantilevered state, is made of a resin material such as polypropylene, which is less deformable than elastomer but can undergo elastic deformation when it comes into contact with the road surface. Therefore, when the movable panel 11 comes into contact with the road surface, it swings upward while undergoing elastic deformation (bending deformation), but when the road surface contact is removed, the movable panel 11 returns to its normal horizontal position due to its own restoring force. The soft deformable member 13 deforms (bends or is stretched) while following the vertical movement of the movable panel 11.

[0055] (4) In the vehicle understructure of this embodiment, it is preferable that the length of the longitudinal cross-section of the deformation member 13 in the front portion 4a of the under cover 4 shown in Figure 9 (i.e., the total length of the portion that extends curved from the front end 13b to the rear end 13c) is greater than the length of the cross-section of the deformation member 13 in the vehicle width direction of the side portion 4b of the under cover 4 shown in Figure 8 (i.e., the total length of the portion that extends curved from the outer end 13d in the vehicle width direction to the inner end 13e in the vehicle width direction).

[0056] With this configuration, the range of oscillation of the front end 11c of the movable panel 11 in the vertical direction Z is increased, making it possible to more reliably prevent damage to the under cover 4 when it comes into contact with the road surface.

[0057] (5) In the vehicle understructure of this embodiment, as shown in Figures 6 and 9, the deformation member 13 extends between the front end 11c of the movable panel 11 and the fixed frame 12 to a length such that when the front end 11c of the movable panel 11 moves upward, the deformation member 13 is less than or equal to the height of the front end 13b of the deformation member 13.

[0058] With this configuration, the deformation member 13 extends to the above length between the front end 11c of the movable panel 11 and the fixed frame 12. As a result, when the movable panel 11 comes into contact with the road surface and the front end 11c of the movable panel 11 moves upward, it will be below the height of the front end 13b of the deformation member 13. This eliminates the risk of the front end 11c of the movable panel 11 moving above the front end 13b of the deformation member 13 and pulling on the deformation member 13, causing damage. [Explanation of symbols]

[0059] 1. Vehicle body 2 Front wheels 4 Undercover 4a Front part 4b Side part 11 Movable Panels 11a Bottom part 11b Front slope 11c Front end 11d Rear end 11e Side edge 12 Fixed Frame 12a Front part 12b Side part 12c Front fixing part 12d Rear fixed part 13 Deformed member 13b Front end 13c Rear end 13d Outer edge in the vehicle width direction 13e Inner end in the vehicle width direction

Claims

1. It is equipped with an under cover that covers the bottom surface of the vehicle body in front of a pair of front wheels and in the area between the pair of front wheels, The under cover comprises a movable panel that can move vertically, a fixed frame positioned above the movable panel and fixed to the bottom surface of the vehicle body, and a deformable member that connects at least the front end of the movable panel to the fixed frame. The deformable member is made of a material softer than the movable panel and is configured to deform when the movable panel comes into contact with the road surface, thereby enabling the movable panel to move upward. A vehicle understructure characterized by the following features.

2. In the vehicle understructure according to claim 1, The aforementioned movable panel is made of polypropylene, The deformable member is made of elastomer. A vehicle understructure characterized by the following features.

3. In the vehicle understructure according to claim 1 or 2, The deformation member is arranged along the entire front end of the movable panel and the side ends on both sides in the vehicle width direction, excluding the rear end. The rear end of the movable panel is fixed to the fixed frame. A vehicle understructure characterized by the following features.

4. In the vehicle understructure according to claim 3, The length of the cross-sectional area of ​​the deformation member in the front portion of the under cover in the front direction is greater than the length of the cross-sectional area of ​​the deformation member in the width direction of the vehicle in the side portion of the under cover. A vehicle understructure characterized by the following features.

5. In the vehicle understructure according to claim 1 or 2, The deformation member extends between the front end of the movable panel and the fixed frame to a length such that when the front end of the movable panel moves upward, the deformation member's length becomes less than or equal to the height of the front end of the deformation member. A vehicle understructure characterized by the following features.

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